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The Fishroom Library Archives —
Articles on Fish Species and Related Topics — (1996-2005)
An archived collection of articles, tips, and information about tropical fishkeeping in general, and killi-keeping in particular, from past issues of the G.C.K.A. Newsletter. To read an article, please click on the title (in blue).
All material is copyright © G.C.K.A. or the authors, unless otherwise noted. Reproduction is permitted for non-commercial purposes only (i.e., club bulletins). We do request that you provide source credit, and send us a copy of the publication in which the article appears. Please forward to G.C.K.A., c/o Recktenwalt, 4337 Ridgepath Drive, Dayton, OH 45424.
Adinia xenica – a native killifish.
Aplocheilus lineatus
A new color form of Aplochileus lineatus
Cubanichthys cubensis – The Cuban Pupfish
Cynolebias antenori
Cynolebias magnificus
New Cynolebias populations found
Cyprinodon atrorus – the Coahuilan Pupfish
Pity the poor pecos pupfish – Cyprinodon pecosensis
Epiplatys chaperi
Fundulopanchax sjoestedti – the Dwarf Red Gularis
Fundulopanchax spoorenbergi
Fundulus cingulatus – an attractive American native.
The Fundulus Family – olivaceus, notatus, euryzonus – An Overview
Fundulus heteroclitus – the mummichog
Mutated Mummichogs (Fundulus heteroclitus) are humans driving evolution?
Jordanella floridae – the Florida Flagfish
Nothobranchius eggersi – a clarification
Nothobranchius guentheri
Nothobranchius species Kisaki and Kwaraza
Nothobranchius kafuensis
Color variation in Nothobranchius korthause
Nothobranchius palmqvisti – a matter of some confusion
The Pachypanchax Family
Care and Maintenance of Pachypanchax omonolatus Nosy Be
Rachovia brevis –an interesting annual.
Renova oscari – a “new” species appears in the hobby.
Rivulus cylindraceus
Riviulus xiphidius – a perennial favorite.
Rivulus xiphidius – a beautiful favorite
An Attractive Native – Adinia xenica
Central and southern North America boast a number of native killifish species, some of them as interesting and colorful as any found in Africa or South America. One that is rarely seen in the hobby is Adinia xenica, the Diamond Killifish.
A peaceful, active and beautiful species, A. xenica is native to the tidal swamps and mangroves of the southern U.S. from Florida to Texas. The basic color of the male is dark gray, with a large number of unequally sized vertical silver bars marking the sides. The unpaired fins are dark gray to nearly black, with silver spots and stripes. The dorsal usually sports a white border, and the anal fin may have a yellow tint. Females have similar but paler markings and coloration, with the unpaired fins showing a gray mottling.
This salt and brackish water fish appears to adapt well to various salinity levels. Although it will survive in fresh water, long term maintenance in fresh water presents problems; the fish may develop enlarged thyroids (hyperplasia). The fish will only thrive and breed in brackish or salt water.
Neal Foster reports that he has kept A. xenica in one-sixth seawater. Mike Wilson has maintained his in salt water with a specific gravity of 1.012, along with Floridicthys carpio. He suggests use of a power filter, since the fish revels in water currents. Mike and Jaap DeGreef have collected this species in coastal mangrove areas with numerous inlets that experienced strong tidal influences. “Interestingly, we’ve never been able to find A. xenica in the area at low tide. When tidal influence is bringing in the water, there are small groups or pairs all around. As long as we go to collect on the incoming tide, we can be assured of the collection of some specimens.”
Mike says that the species is easy to feed and breed, but that they seem to do best in groups for long term maintenance, and in pairs for breeding. “A group of 6 to 10 adults in a 20 long is an attractive sight, with very little aggressive behavior apparent.” Newly hatched brine shrimp seems to be the food of choice, but other foods (including dry flakes) are readily accepted.
The eggs are placed in mops, on corks, in gravel, in filters, in rock crevices. “If you can’t find eggs where you expect them,” Mike says, “just keep looking.” Incubation is fairly short, with bag eggs infrequent. The eggs are large and the females tend to produce a few eggs each day over a long period.
The fry grow rapidly, and sexual differentiation occurs at about three months of age.
— G.C.K.A. Newsletter, June 1997 Return to top of page
This species has long been a staple of the aquarium hobby. The original wild form, marked by gold spangles and red highlights, is still occasionally seen, but more common now is the selectively bred “gold” form. This variety, which features a yellow-gold body and fins with an iridescent sheen overall, is being bred in large numbers for the aquarium trade and can often be found in fish stores.
Ap. lineatus is hardy and fairly easy to keep and breed. Give them a 10 gal. tank or larger with plenty of plants and a spawning mop or two. Collect eggs regularly for separate incubation – the adults don’t usually bother the eggs, but they are notorious fry eaters. The eggs hatch in about two weeks, and fry grow quickly.
Origin: India, Sri Lanka
Size: to 4″
Temperament: Generally peaceful to fish its own size or larger. Smaller specimens will be considered as lunch.
Maintenance: Prefers soft, slightly acid water, 70-80° F, with some plants. Breeding is easy in mops. Collect eggs every few days and raise fry separately.. Collect eggs every few days and raise fry separately.
— G.C.K.A. Newsletter, August 2005 Return to top of page
A new color form of Aplocheilus lineatus
Recently a new color form of A. lineatus has appeared in the aquarium hobby – Gold. Like the gold forms that have appeared in other fairly common species, it is assumed that the Gold Lineatus is a color morph which arose as a mutation from regular stock.
However, as Mike Wilson points out, the Gold Lineatus appears not to be a xanthistic morph with a reduction of melanophores as seen in Aphyosemion australe Gold. “The specimens are essentially normal appearing LIN with the male showing an abundance of bright yellow scalation, appearing as a metallic yellow wash in abundance over the body of the males.” Males often have white tipped fin filaments and orange fin edges; the females are generally silvery in color.
The “Golden Wonder Killie”
The strain was apparently sold in New Zealand as “Golden Wonder Killies”, and in the U.K. as “Golden Wander Panchax” (perhaps named after a local brand of crisps [potato chips]).
“It will be interesting to test the coloration stability … and to determine if carotenoids will serve to maintain or enhance the pigmentation.”
Given their prolific nature, the strain could have commercial potential. Many aquarists have had success with A. lineatus, whichare fairly hardy, prolific, and tolerant of a wide range of aquarium conditions, doing well in any type of water, at ordinary temperatures. They will eat almost anything that floats, and that they can get their mouths around – brine shrimp, daphnia, tubifex, fruit flies, blackworms, glass worms, flake and frozen foods, etc.
Breeding
Breeding is easy, using either floating mops or the permanent setup method with a plant filled tank, rotating the parents out after two weeks. “I hadn’t seen any eggs,” says George Davis of the rotation method, “but I got 85 young from a … two week spawning session.” With the rotation method, fry hatch out over a period of several weeks and grow without disturbance, feeding on the natural foods in the tank and supplemental brine shrimp or microworms.
Alternatively, the eggs may be picked from mops for incubation elsewhere. They are quite large, clear when first laid, turning dark as they develop. Incubation is generally 14-21 days at 72° F. The eggs do well in a hatch mix of methylene blue, acriflavine and Aquarisol.
One problem that has been noted with the species is a low fertility rate with young fish, and a resultant high loss of eggs to fungus. However, as the fish mature fertility improves and the loss rate drops.
— G.C.K.A. Newsletter, June, 1998 Return to top of page
Cubanichthys cubensis, The Cuban Pupfish
Unlike many of the known pupfish species, which have (or had) habitats so extremely limited that the slightest variance put them at the brink of extinction, the Cuban Pupfish, Cubanichthys cubensis, occurs in a wide variety of habitats. They have been found in the freshwater interior rivers of Cuba, in swampy lowland lagoons filled with vegetation, in fairly soft to extremely hard water, and even in brackish habitats.
These fish fall into the usual size ranges for killifish: 3 inches for the males, and slightly smaller for the females. Coloration is muted: the body color is a mottled semi-transparent golden tan. A creamy white patch begins behind the gill covers and arches diagonally to the anal fin, encompassing the vital organs. In both sexes, a series of horizontal light blue lines overlay the base color, beginning at the gill covers and extending through the caudal peduncle. A broken dark line often runs from the lower jaw through the center of the eye, and onto the upper gill cover. In the males, coloration is brighter, and the more pronounced blue lines continue onto the bases of the anal and dorsal fins. As in many pupfish, the finnage on the males is more extravagant, with extensions to the dorsal and anal fins; the caudal may show a distinct wash of blue. The plainer females may show mottling or splotching along the midline of the body.
Cuban pupfish are fairly quiet, unsociable, timid fish that tend to do fairly well in small aquaria, but do require well-aerated, slightly alkaline (pH value over 7), clear water at all times. A substrate containing detritus is beneficial, and plants are important. Frequent partial water changes are essential, but sudden complete water changes or transfer into different water should be avoided, since this often results in illness or death of the fish.
The addition of crystalline calcium chloride to the water at the rate of 1 ml (ccm) of the saturated calcium chloride solution per 3-5 liters of aquarium water has proven highly beneficial. Both the adult fish and the fry seem to benefit from a weak solution of trypaflavin, which protects them against infection, although other medications commonly used with aquarium fish are often detrimental or toxic to this species.
During a several day spawning period the females lay up to 10 eggs daily, laid one at a time on water plants. Occasionally a small cluster of eggs will be seen hanging from the female’s urogenital papilla on sticky threads. These are usually soon rubbed off on water plants. The eggs are fairly large, transparent, strongly adhesive, and measure 1.4 mm in size. Since the adults often eat the eggs, transfer of the spawn to a separate aquarium for hatching is desirable. Dr. Stanislav Frank reported his best success when he reared fry in water that measured 10° DGH hardness, 6° DGH carbonate hardness, 4° DNKH noncarbonate hardness, chloride 75 mg/ liter, and pH of 7.6. At 79° F (26° C) the eggs hatched in six to seven days. The fry were free-swimming after three more days, at which time they began to accept live food. Fry were short and robust in form, with an average length of 3.4 mm (less than 1/6 inch). Growth rates are fairly slow; the fry are sexually mature at 4-5 months, and reach full growth between 8-9 months.
Reference: Frank, Dr. Stanislav, “The Care and Breeding of the Cuba Pupfish, Cubanichthys cubensis,” Tropical Fish Hobbyist, November 1985, pp. 70-72.– G.C.K.A. Newsletter, December 1999 Return to top of page
New Cynolebias Populations Found
Cal Hin, on the Killifish Mailling List on September 15, reports that he has been advised of a new collection made in Uruguay recently.
Among those populations found were: Cynolebias elongatus, with females 18 cm and males 7 cm in length.
A new population of Cynolebias cherapodphilus, which appear to be the same as those previously collected, although taken from a different site.
Cynolebias melanoorus.
A new population of Cynolebias alexandri, in the San Javier (Uruguay) area, found with Cynolebias nigripinnis (observed, not collected – a teacher had them in a tank, and was teaching her students how to keep the fish that lived in a pond 4 meters from the school).
Two types of Cynolebias alexandrii, one spotted, the other not.
Cynolebias prognathus, collected in a pond that had not yielded the species on several previous visits.
— G.C.K.A. Newsletter, November 1996 Return to top of pageCynolebias antenori
This is a typically deep-bodied Cynolebias species, named for its original collector, Dr. Antenori L. de Carvalho of the Museum Nacional de Rio de Janeiro, Brasil. Information on its discovery and the presumptive type locality were given by Myers in “Annual Fishes,” Aquarium Journal (San Francisco) 23:125-141; specifically, on page 134. Prof. Myers apparently intended to publish a complete description, but never did so. The type specimens were collected from temporary pools and cattle tracks near Russas, a town on the Rio Jaguaribe, Ceara, Brazil. It is now known from at least two other locations in the states of Ceara and Rio Grande del Norte.
The species is currently available in the hobby, although it is not particularly common. Some discussion remains regarding its actual name. Although the original collection and discussion of this species and its biotope came from Myers, Jean H. Huber has described it as C. heloplites.
C. antenori is approximately intermediate between species like C. bellottii and the elongate C. whitei, in shape and general appearance. Males have elongate subterminal dorsal and anal fin rays and a conspicuous color pattern; females lack the fin extensions and are more plainly colored.
This is a reasonably hardy and undemanding species that prefers higher temperatures of 75-80°F, but can be maintained and bred at 70°F. A pair or trio is easily kept in a three gallon aquarium. Adults will accept frozen and live foods; some will take flake foods. Males may be aggressive, and hiding places should be provided for females. Both sexes establish dominance hierarchies and engage in more display behavior than is usual for other Cynolebias species. Fighting among males is frequent.
The general body color of the males is light steel gray to gray-blue, dorsum darker with a bronze sheen and the pearl-like metallic spots. The anterior half of the body has faint and indistinct vertical bars. The iris of the eye is golden, crossed by a dark vertical bar. Pectoral fins are colorless to faint blue. The basic ground color of the single fins varies from dark blue-green to yellow-green with rows of white pearl spots. The anal fin has a marginal black band and a submarginal zone of yellow to intense red-orange. The pelvic fins continue the anal fin pattern, with red bases and faint black tips. The intensity of coloration is a function of temperature, age, social position, and sexual arousal.
Females tend to have a light brown body color with 3 to 5 rows of dark vertical “worm-like” markings, posteriorly dorsal darker. One to three large dark ocelli on the mid region of the flank; the number of spots may not be symmetrical. The caudal peduncle has a single black spot. Some specimens have faint brown markings on the base of the anal fin.
The species is not difficult to propagate. C. antenori is a substrate diving species best spawned over peat moss or walnut shells 1.5 inches deep. Isolation and conditioning of females is recommended but not essential. Incubation in dry peat is 5 months minimum, with optimal time of 6-7 months. Fry will take brine shrimp nauplii upon hatching. Sexual dimorphism is apparent within 30-40 days.
References: Weber, Dale. E-mail to the Killifish Mailing List, March 1996, citing Campello, Brasil, G., 1973 and 1974; Langton, R.W., 1972; Myers, G.S., 1952; Nielsen, D., 1975; and Tulipano, J., 1973.
– G.C.K.A. Newsletter, September 1999 Return to top of page
Native to the middle Sao Francisco basin, Minas Gerais, in Central Brazil, this is one of those lovely South American annuals that seems to be holding its own in the killifish hobby, appearing in fish shows with fair regularity.
Well-colored males are predominantly purplish with a green sheen anteriorly and a reddish dorsal region. Blue dots cover the sides, except for the belly area. There are two or three faint bars below the forward edge of the dorsal fin. The dorsal fin is pointed, the anal fin slightly extended but not pointed, the caudal fin rounded. The unpaired fins are red with transverse rows of greenish blue stripes.
Females are pale brown with dark bars and spotting and a lighter belly region. The unpaired fins are hyaline.
Maintenance, Spawning and Incubation
In general, this seems to be a not difficult species to breed. Water parameters do not seem to be critical (soft water is recommended, but Brian Watters says he has kept C. magnificus in the same water he uses for his Nothos – pH 7.8-8.0, TDS 250, and they seem to do just as well. Eggs are 1.0 mm, clear to amber in color.
Adults will eat any of the regular live and frozen foods, but do seem to prefer smaller live foods. Fry are able to take newly-hatched brine shrimp.
“I have been maintaining and breeding this species with considerable success for some time and the most important factor for success is patience,” says Brian Watters. Incubation times are erratic and very long. Brian has had only three fry hatch at less than 9 months’ incubation; most have hatched after an incubation of at least 10 months, and repeated wettings of two year old peat still yield fry. Egg development can be speeded up by using higher temperatures, but this also produces more belly slider fry. Brian recommends “normal” incubation temperatures of 24-25° C (75-76° F).
Brian maintains his fish in moderately soft water with a pH of about 7.5, TDS 80-100, He uses either a half-inch layer of peat on the bottom for spawning, or a peat-filled plastic container with a hole cut in the lid. Be certain to siphon off any peat that is spilled, he cautions, since the fish will spawn in any peat and you can save a large number from that “yucky” stuff. “Generally, one tends to underestimate the number of eggs in a spawning.”
“I raise this fish at 24-26° C (75-79° F),” reports Cal Him, “using a small container of peat moss as the spawning medium.” His fish are raised in 40 l tanks with soft water having a pH of 6.0-6.5. Fish may start spawning at four months of age. The fish is fairly prolific, but eggs seem to have no ideal incubation period, with eggs hatching from 3 months to 2 years. “I have been trying to keep the eggs at 30° C (86° F),” and have had some success.”
Christian Rosskopf has tried storing the peat at higher temperatures, 33° C (91° F) during the day, and 25° C (77° F) at night. After seven weeks he got a large hatch, but with 99% females. “I don’t think the sex of the fish depends on the temperatures at which the fry are raised,” says Christian. “I think it depends on the temperature at which the eggs are laid.” He has bred C. magnificus at 25° D (77° F). Christian observes, “in the past I’ve found that pH is unimportant in breeding fish” (pH in his tanks is about 7.5). What is more important, he feels, is to use soft, but not necessarily acid water.
Robert Nahn’s experience with the species is somewhat different. The eggs of C. magnificus are small and “very difficult to find in [wet] peat, as I keep the peat very moist.” Incubation at 78-80° F takes about 4-1/2 months, and again at 12 months. Hatches tend to be good, with 200 fry not uncommon. Robert reports that he keeps 10-15 fry in a shoebox, and that he usually gets about 30% females.
— G.C.K.A. Newsletter, November 2002 Return to top of page
The Coahuilan Pupfish – Cyprinodon atrorus
Unique to the Cuatro Ciénegas Basin, the Coahuilan Pupfish is restricted to the saline waters of the area’s lakes, pools, marshes, and non-thermal springs and their outflows.
Although listed as Threatened by the Mexican government in 1994, the fish is common to remarkably abundant in restricted, local areas. They are usually found in warm (15-45°C) shallow (less than 25 cm) water, over a soft, flocculent, algae-rich bed, where they feed on detritus, algae and small invertebrates.
Behavior of the fish appears to be temperature dependent; below 15°C the sexes mix in loose aggregations of all sizes; at warmer temperatures males and females remain strictly segregated except during breeding. Between 25-45°C males form territories in extremely shallow water, usually less than 5 cm; territory size, posturing, and spawning display all vary with habitat. The females enter the territories only to spawn.
Eggs hatch in a few days and the young move freely throughout their environment. Growth is rapid, with sexual maturity achieved in a matter of weeks at summer temperatures.
– GCKA Newsletter, July 1998 Return to top of page
Pity the Poor Pecos Pupfish … (Cyprinodon pecosensis)
The Pecos pupfish (Cyprinodon pecosensis) of New Mexico faces extinction. Not from habitat loss or human encroachment, but from fickle females.
Scientists have found that the female Pecos Pupfish much prefer males of the Sheepshead Minnow (C. variegatus) as mates. This has lead to hybrid offspring that are more successful than either parent species at defending their breeding territories. For the Pecos pupfish, the consequences have been severe. In five years during the 1980s they were replaced across most of their native range, by their hybrid offspring. Originally inhabiting a 300-or-so-mile stretch of the Pecos River, the pure Pecos pupfish survives now only in isolated spring and sink holes.
In 1999 New Mexico, Texas, the U.S. Fish and Wildlife Service, and the Federal Bureau of Land Management signed an agreement to conserve the Pecos pupfish. Potential habitats were to include Bottomless Lakes State Park, southeast of Roswell, N.M., and private lands in Texas.
Researchers Jonathan Rosenfield and Astrid Kodric-Brown from the University of New Mexico, Albuquerque, believe they have witnessed one of the methods for creation of a new species. “The hybrid zone spread extremely quickly,” says Craig Stockwell, a conservation biologist and pupfish researcher at North Dakota State University.
Other freshwater fish are threatened by the same type of inter-species mating behavior. Roughly 40% of endangered species may be at risk of hybridizing with related exotic species.
References: “Fickle females drive Pecos pupfish to extinction.” Glasgow Herald, June 15, 2000.
“N.M., Texas Agree: Conserve Pupfish.” Albuquerque Journal, March 17, 1999.
“Science Notes.” The Fort Worth Star-Telegram, June 25, 2000.
— G.C.K.A. Newsletter, September 2003 Return to top of page
E. chaperi was first described and named in 1882 by H. E. Sauvage, who based his description on specimens collected by M. Chaper near Couracrou, in the eastern part of the Gold Coast (today the Ivory Coast). However, due to a misidentification by G. A. Boulenger, the species was for some time confused with E. dageti Monroviae, which was distributed under the E. chaperi name. This confusion existed until 1964, when J. Daget and J. Arnoult resolved the confusion, based on study of Sauvage’s original specimens, and subsequently brought E. chaperi out of obscurity.
E. chaperi is one of the “quiet” killies, tending to spend much time motionless in one spot, usually just below the surface. They tend to be more animated when kept with other tropical fish than when kept in species groupings.
Body shape is typical for the Epiplatys, with dark crossbars on the sides, the number and placement of which aids in differentiating the various subspecies. Both have black bars around the chin and lips, and an iridescent spot on the head between the eyes. Females are not as intensely colored as males, and often develop additional barring on the sides. In the center of the caudal fin the rays are elongated to form a square extension.
The species occurs in a fairly large natural range in permanent slow-moving or standing waters filled with vegetation, throughout forest and savanna habitats from southeastern Guinea south and east to the Togo Hills in eastern Ghana. In the forest (woodland) habitats waters are cooler and darker than those in the savanna areas. Native waters are usually acid and soft, with a high concentration of humic acid from decaying vegetation.
Such wide variation in natural habitat seems to make E. chaperi an excellent aquarium fish. In the aquarium the species seems content at a pH of 7.2-7.4, with moderately hard water,does not appear sensitive to bright light, can tolerate a wide range of temperatures, and will eat a variety of freeze dried, frozen and flake foods.
Spawning is typical for the genus, with spawning mops readily accepted. For breeding a trio is recommended, with preconditioning of the females. Egg production is not as good as with E. dageti or E. sexfasciatus, however. Fry hatch in 13-15 days, and growth is moderate. Separation by size is recommended.
Four distinct subspecies, differentiated primarily by their coloration, are recognized, with numerous additional populations found which exhibit highly variable “intermediate” colorations. Hybridization experiments seem to indicate that all E. chaperi, however colored, are reproductively the same.
E chaperi chaperi chaperi (Savage 1882) occupies a restricted range in the southeastern Ivory Coast and southwesternGhana. Basic coloration is pinkish-gray with a purple sheen. A maroon dot marks each scale, suggesting broken horizontal stripes. The dorsal fin is dark edged blue to black, the anal fin has a bright orange border, and the caudal fin is edged in orange and blue. Four bars mark the rear half of the body, the first starting just before the first ray of the anal fin.
E. chaperi sheljuzhkoi (Poll 1953) comes from southwestern Ghana, south of the range of E. chaperi chaperi. The body has an overall blue sheen which extends into the unpaired fins. The subspecies has five dark bars, the first located next to the pectoral fins, the rest placed as for E. chaperi chaperi. Red reticulations mark the scales. Males often develop a row of large dark red spots near the base of the anal fin, which is deeply edged in black.
E. chaperi spillmanni (Arnoult 1960) is found near the city of Bouake, in the centralIvory Coast.Coloration is similar to E. chaperi sheljuzhkoi.
E. chaperi schreiberi (Berkenkamp 1975) comes from an area around Kumasi, Ghana, north of the range of E. chaperi chaperi and E. chaperi sheljuzhkoi. This subspecies has no body sheen; the red spots are evenly distributed over the body and fins in no particular pattern. The caudal and dorsal fins have a blueish/white edge. Five dark bars are present, four as in E. chaperi chaperi and the fifth located at the base of the ventral fins.
Reference: Sellers, Karen and Jerry. “The Real One,” Killie Kolumn, Freshwater and Marine Aquarium, January 1986.
— G.C.K.A. Newsletter, November 1998 Return to top of page
Fundulopanchax sjoestedti Dwarf Red
Water Conditions and Tank Setup
Dwarf Red Gularis are very adaptable, but like all killifish, they are jumpers. Probably the most important thing to remember with these fish is to keep the tank covered.
Dwarf Reds will prosper in a variety of water conditions, ranging from soft to moderately hard, providing that changes in water conditions are done slowly. They do best at temperatures ranging from 72 to 80F, although they can tolerate lower and higher temperatures for short periods of time.
Unlike many killifish, Dwarf Red Gularis can be found at all levels of the tank, although they spend most of their time toward the top of the water. They seem to appreciate plants and other tank decor, and are far less likely to jump if in a planted tank.
Feeding
Dwarf Red Gularis are not picky eaters. They can be well maintained on flake foods (Brine Shrimp Plus flakes work well), but they will also greedily eat frozen foods (blood worms and brine shrimp are favorites) and live (mosquito larvae and daphnia). These fish will show the best color and growth if they get some frozen and live foods in their diets.
Suggested Tankmates
Dwarf Red Gularis can be comfortably be kept in a 15 or 20 gallon community tank. Small, peaceful cichlids (Kribensis work well), many tetras and barbs (as long as they are too big for the Dwarf Red Gularis to swallow) and many livebearers (platies and swordtails are a great match) can be housed with Dwarf Red Gularis.
However, NEVER place Dwarf Red Gularis in with a male betta. Both fish have the same threat display (flaring fins and gills) and the Dwarf Red Gularis will kill the betta within a short time. They are also not good tank mates for any other gouramis or paradise fish for the same reason.
Breeding
Dward Reds are “switch spawners,” using either plants or peat as their pawning medium. Incubation is variable, ranging from two to six weeks (shorter in water, longer on peat). Fry are able to take baby brine shrimp or other small live foods upon hatching.
Comments
Dwarf Red Gularis are hardy and adaptable fish that can be expected to live for two or three years in aquariums if their needs are met. They are one of the brightest colored strains of Fundulopanchax sjoestedti avialable in the hobby. Fertility can be highly variable, depending on the strain and on the age of the fish.
— G.C.K.A. Newsletter, May 2004 Return to top of page
Among the hundreds of species of killifish, coloration ranges from nearly nonexistent (the silvery, iridescent lampeyes) to the spectacular, represented by some of the African annual Nothobranchius species. Among those that fall “in between,” perhaps one of the most colorful is Fundulopanchax spoorenbergi.
This robust, elongate fish, which may reach 3″ in length, was originally discovered by Dutch aquarist Frank Spoorenberg, who came upon it in the tanks of a commercial aquarium store. Although the species is believed to have originated somewhere in the Nigeria-Cameroon border area, no type locality is known. It Is also known by several synonyms: F. sp. “GAR-MIR” (J. Scheel), and A. gardneri obudense (Wright and Jeremy 1974, Scheel 1990). It appears to be related to the complex that includes F. cinnamomeum, F. gardneri, and F. mirabile.
In coloration and pattern, male F. spoorenbergi sport a wide range of variability, but generally have a bright yellow to yellow-green base color that shades to brown on the back, and to white in the belly area. The forepart of the body has a bluish sheen, and large dark red splotches mark the body in various longitudinal and zig-zag patterns. The unpaired fins are golden yellow to greenish; the dorsal is spotted with red and bears a wide red border edged in green. The anal fin carries spots near the body, and a red border. The caudal fin has bright yellow margins with slight extensions, and dark red submarginal bands.
The female is much less flamboyant than the male, but more colorful than many killifish females. Body color is a warm tan shade, lighter in the belly region, with numerous small red spots arranged in longitudinal lines on the main part of the body. Unpaired fins are yellow-orange with some red spotting.
F. spoorenbergi can be considered one of the “semi-annual” species. It lays its eggs on fine leaved plants or mops. The eggs can be hand picked and incubated either in water (2-3 weeks), or on damp peat moss (6 weeks). Some aquarists consider the fish “moderately difficult” to breed; others classify them as “fairly easy.” Recommendations are to keep a pair or a trio in a small, heavily planted tank. Water should be medium to hard, neutral to slightly acid.
The author bred F. spoorenbergi in a bare bottomed 5 gallon tank containing both bottom and floating mops, a mass of Java Moss and a sponge filter. Temperature range was 70-75° F, hardness 180 ppm, pH 6.8 Water changes were weekly, from 10-20%, using tap water (pH 7) treated for Chlorine and Chloramine and aged overnight. The adults were fed on a mixed regimen of flake, frozen, and live foods. Eggs were picked and incubated either in water or on peat. Even more effective was letting the fry hatch out in the tank with their parents. The adults seemed to ignore the fry and predation was no problem.
The fry grew steadily on a diet of microworms, decapsulated and frozen baby brine shrimp, and Sanders brand Fry Gold powdered food. They were fairly large, and soon graduated to finely crumbled flake foods.
– G.C.K.A. Newsletter, December 2002 Return to top of page
In Our Own Backyards …
Fundulus cingulatus
Many aquarists despair when it comes to keeping killifish native to the United States, since many species tend to be rather dull in coloration and uninteresting in either reproductive behavior or personality.
However, Fundulus cingulatus is hardly one of those ordinary brown fishes. F. cingulatus is a moderately sized killifish, with a maximum size of about 3 inches and a shape similar to the more familiar F. chrysotus. Male F. cingulatus are slightly reddish with bright, lemonade pink fins; the tail may have a gray border. In subdued lighting the unpaired fins may take on a deep rosy hue, and horizontal rows of red dots are noticeable along the sides. The eyes of the male reflect a blue sheen, and have an hourglass shaped pupil, a clear indicator of sex. Females are pale in comparison, and show a slight vertical bar along their flanks; they look much like female F. cyrosotus, but without the glittery spots on the sides. Females also tend to show a fleshy area at the leading edge of the anal fin.
These fish, which have become rarer in recent years, are usually found in tidepools along the lower parts of streams and in sluggish, lowland creeks. The species seems to be tolerant of brackish water, but prefers fresh water with just a bit of salinity. It has often been found in areas where red algae thrives, which may partially explain the distinctive coloration of the males.
An Active, Friendly Fish
This species is an upper-level, active chaser that requires plenty of swimming room. Bob McDonnel kept them in a 29 gallon tank that had housed Jordanella floridae. The water was moderately soft, warm (27° C/80° F), with slightly raised salinity (about 1 tsp. of Instant Ocean marine mix per gallon). The decor was simple, consisting primarily of rocks, driftwood and both live and artificial plants. The fish fed readily, willingly taking flakes and any other foods that were offered. Regular water changes and the presence of Malayan Livebearing Snails maintained water quality in the sparsely populated tank The fish tended to be active all the time, were not startled by viewer scrutiny, and enthusiastically greeted the aquarist at feeding time.
Propagation was fairly straightforward. Chasing and courtship were evident in the large tank early on; actual spawning was accomplished in a 2 gallon drum bowl nearly filled with yarn mops and several quarts of water from the main tank.
A single pair of conditioned fish were placed together and left for 4 to 7 days, being fed only live foods (to maintain cleanliness) and a little green water. On the eighth day the pair (still compatible and vigorous) were returned to the main tank.
The eggs were relatively large and developed well at the slightly lower temperature of the bowl (74° F). After approximately two weeks they began to hatch, and java moss was added to the spawning container.
The fry were fairly easy to rear although they grew fairly slowly for the first few days. They actively took brine shrimp nauplii and other small food items, including green water, vinegar eels, and commercial baby fish food formulations. A pond snail was added to boost infusoria and to eat unconsumed material. A 50% water change was done every other day.
— G. C. K. A. Newsletter, July 1998 Return to top of page
The Fundulus Family – olivaceus, notatus, euryzonus
“The Fundulus notatus/F. olivaceus issue is fairly well known to American ichthyologists,” says Bruce Turner, “and has attracted attention from several, including Jim Thomerson (who did his dissertation research on the two forms) and Robert Cashner of LSU,” who surveyed their variation and described a third form, F. euryzonas, from the Lake Pontchartrain drainage in Mississippi and Alabama. Thomerson and the late Carl Hubs had both recognized that the F. euryzonus form was divergent, but had no proof.
F. olivaceus and F. notatus now appear to be “sibling” species, since they are morphologically difficult to distinguish but are genetically distinctive. There is much research still to be done, however. Does their separation remain the same over seasonal fluctuations in habitat size, movement, water temperatures, etc.?
F. olivaceus and F. notatus
“I’ve only [collected] F. olivaceus types in the Wolf drainage [of Tennessee],” says Shane Essary. “But F. olivaceus has that ‘faint’ yet distinctive notatus looking line that runs from head to tail. Yet all these fish fit more the olivaceus provile (lots of specks) and that notatus line is VERY faint. On the other hand, in the Hatchie drainage I find nothing but dark banded killies (notatus), with faint spots. Really, the two fish look almost just alike,” and both occur in the western Tennessee range projected by Etnier and Starnes in The Fishes of Tennessee. According to them, F. olivaceus seems to prefer slightly faster flowing streams, and in unchannellized streams seems to avoid the sluggish downstream areas. F. notatus tends to prefer the more sluggish areas. This ecological separation was also noted by Braasch and Smith (1965).
“Both these species that I have collected were in shallow water [1 to 6 inches],” reports B. G. Granier, “regardless of the flow or lack of flow in their respective habitats, which is generally backwater areas or a captive population … in a pond or in the shallow, fast moving current of a creek. They are very difficult to collect, since they are very wary … of [anthing resembling] fish-eating birds.” F. notatus has also been collected in the drainages of southwestern Ohio.
F. euryzonus
This species appears to only inhabit “the deeper part of the streams in Louisiana and Mississippi, and while they may be found against the bank, the depth of the water is generally over the 1-6 inch depths that F. olivaceus and F. notatus are commonly found in,” says B. G. Granier. “I have had to wade out to chest deep water to find F. euryzonus congregated around any current break, such as log jams, man-made breakwaters or deep pools … beneath a bridge, to catch them.”
– G.C.K.A. Newsletter, August Return to top of page
Fundulus heteroclitus – the mummichog
North America boasts a number of native killifish species, with habitats that range from fresh to salt water, and from very hot to occasionally downright frigid.
One of the more common species that can be collected from native waters – and perhaps not particularly popular because of its easy accessibility – is the mummichog, an inhabitant of marshes in estuaries along the U.S. east coast from Maine to northern Florida. Highly tolerant and adaptable, mummichog can survive with high levels of pollution, in ranges from freshwater to pure seawater, and in temperatures as high as 35° C (95° F). Individuals have even been observed to “come back to life” after being frozen for half an hour.
F. heteroclitus is most commonly collected as a bait fish or for scientific study. However, it should not be overlooked as a suitable and attractive aquarium fish. Males in spawning colors sport metallic blue-green spangles on the sides and yellow-gold fins.
Eric Lund offers one cautionary note, however: the species (especially individuals collected in the Chesapeake Bay area) seems prone to infestation by roundworms, with a high percentage of individuals harboring the parasite. Proper quarantine procedures and treatment for such infestation might be wise, to prevent possible contamination of other fish.
— G.C.K.A. Newsletter, January 1998 Return to top of page
An unpretentious little fish, Fundulus heteroclitus, more commonly called the mummichog, has scientists wondering if foul water is driving its evolution. It has learned to thrive in one of the most polluted natural waters in North America, Virginia’s Elizabeth River.
The mummichog could tell us much about the long range impact that human activities may be having on other species. “We’re interested in how human disturbances affect other organisms over multiple generations,” says Richard T. Di Giulio, an environmental toxicologist at Duke University, who is leading a study sponsored by the Office of Naval Research.
Di Giulio believes at least 50 generations have survived in the foul waters of the Elizabeth, adapting to water so polluted that one study calls it a “toxic hot spot.” If the riverbed is disturbed, oil often gurgles to the surface, creating a slick. But when Di Giulio captures the fish and takes them to his lab, many of them die. Fish taken from clean water have no trouble adapting to Di Giulio’s aquarium.
Fortunately, some do survive and reproduce in the aquarium about six weeks after being collected. Some of their offspring survive and reproduce as well. That gives Di Giulio three generations to study.
The results so far are disturbing and inconclusive.
The mummichog paid a price for their adaptation to the murky waters of the Elizabeth. Adult specimens look healthy, but have liver cancer. That was expected because of the high concentration of carcinogens in their home waters. But they also seem to have lost their ability to protect themselves from some bacteria and such things as fungal diseases. Di Giulio believes that the pollution may have killed the bacteria that cause such diseases, and that over time the mummichog’s immune system may have become partially suppressed.
“They are more prone to various infections, and that’s really why they are dying in the lab,” Di Giulio says. “They are dying of various fungal and perhaps bacterial infections.”
Enough have survived, however, to give Di Giulio a chance to determine whether the effort to adapt to the foul waters of the Elizabeth River actually led to evolutionary changes. In other words, did pollution drive evolution? Possibly.
By the third generation, fish reared in the aquarium have lost about half of their resistance to certain toxins, so some adaptations did not alter the mummichog’s genome. Some things, like their susceptibility to fluctuations in the oxygen level in the water, remain constant, but some changes do seem to be taking place.
“What’s important to know is, are we shaping the evolution of organisms?” Di Giulio says. “I think we are. But these fish paid a price. They’ve lost fitness to other natural stressors.”
In the Elizabeth River, thins are getting a little better. A long range effort to clean up the river has been partially successful, but so many tons of creosote, oil, and waste products have been dumped into the river over the years that two Superfund sites have been designated in an effort to clean up the mess. But it will take years.
So the mummichog won’t have it much easier for a long time to come. Maybe when it’s all over, it will have told us much about the long range impact of pollution.
Reference: Dye, Lee. “Mutated Mummichogs: Scientist Studies Tiny Fishes’ Adaptation to Pollution.” Special to ABCNEWS.com, April 17, 2002.
— G.C.K.A. Newsletter, November 1998 Return to top of page
Right In Our Own Back Yards …
Jordanella floridae
One of the few native American killifish to regularly find its way into pet/aquarium shops is the southern American Flagfish, Jordanella floridae.
Flagfish are considered by many to be an ideal beginner’s fish, being undemanding, peaceful, well colored, and with interesting but not necessarily difficult breeding habits.
Even when not in full breeding attire, the fish are attractive. Males show a blue-green base color with horizontal red stripes on the body and fins. Females are basically green with a black dorsal spot. Maximum size for males is about 2 inches; females are smaller.
Requirements are simple: temperature of 65-70° F, water medium hard, neutral or slightly alkaline, with regular partial water changes. Some recommend brackish water, but this is not necessary. Although they are not picky eaters, they are related to pupfish (Cyprinodon) and require either plants to chew on or a high proportion of vegetable matter in the diet.
Aquarists who have bred the fish report that they can be successfully spawned as pairs or in groups, and that they also sometimes act as nesting fish, digging in the substrate and carefully guarding eggs and fry. As with other species of killifish, it is recommended that the breeders be conditioned separately and then brought together in the spawning tank. When the female begins to fill with eggs, increase the temperature to 78-80° F. Add spawning mops and the male, and in a few days begin harvesting eggs.
Methylene blue should be avoided, since it can have an adverse effect on eggs and fry. Once eggs have hatched, add a snail to the container and begin feeding using Liquifry or similar food. Within a day or so the fry, which tend to grow slowly at first and at different rates, can take newly hatched brine shrimp.
— G.C.K.A. Newsletter – October 1997. Return to top of page
Nothobranchius eggersi – a clarification
Among the Nothobranchius species, one of the more spectacular is N. eggersi. It is found both in the wild and in the hobby in two basic color forms (red and blue) and in a transition form.
This species was most recently collected from the wild in 1995 by Brian Watters, Ruud Wildekamp, and Ian Sainthouse.
There has been, and continues to be, some confusion regarding the various strains of this fish, some of which have deteriorated badly during their maintenance within the hobby. The original strain of N. eggersi (red) was never a pure strain, and has now deteriorated and exhibits unusually stubby bodies. Viability of the blue form has also deteriorated, with many deaths reported among the young stock.
According to Brian Watters, the fish known originally as N. eggersi (Red), N. eggersi Rufiji River Camp and N. eggersi (Red) Selous Game Reserve all belong to the same strain. This strain was never pure; the aquarium strain began with a male N. eggersi (Red) and a female of the Ruhoi River strain (Blue), since no females of the Red form were available.
The original N. eggersi Ruhoi , also known as N. eggersi (Blue) was a pure strain.
On their 1995 collecting trip, Wildekamp, Sainthouse and Watters were able to collect the Rufiji River Camp (Red) form, to recollect the Ruhoi River (Blue) form, and to find a dominantly Blue form in the Rufiji River Camp area. Collected and subsequently introduced to the hobby were: N. eggersi Rufiji River Camp TAN 95/7 (Red);
N. eggersi Rufiji River Camp TAN 95/8; and
N. eggersi Ruhoi River TAN 95/11 (Blue).
Since confusion does exist regarding the populations and strains of these fish, and since there is a very real possibility of producing sterile “hybrids” if populations are mixed, it is very important to maintain the strains pure, and retain all collection code information through subsequent generations.
— G.C.K.A. Newsletter – October 1997 Return to top of page
Nothobranchius guentheri – a question of color
One of the pleasures of working with killifish is the wide range of colors and patterns available, some of them within a single species. In many cases, these variances can be explained by divergence, by the ultimate isolation of populations in the wild, and by natural genetic drift over time. In some species, however, different color forms have been discovered in the same pools. Just to make things more interesting, some forms have been selectively developed by fishkeepers.
Nothobranchius guentheri is one of a number of species that are available in several different color variations. Some types have been wild-caught, while others appeared as sports (mutations) in hobbyists’ tanks.
Females of all forms are typically Nothobranchius plain –undistinguished tan to pale silvery brown.
In contrast, the wild forms of GUE show a fairly wide divergence in coloration. Body color in the males ranges from yellow, to bright or pale blue, to blue with a greenish tinge. Individual scales have a red edge that varies in width, resulting in body patterns that may be fine and netlike, or actually produce discernable stripes. Dorsal fins may be yellow or red, often with a bluish edge, and like the anal fin, may be solid or patterned. In the wild forms, the tail is uniformly red, with or without a dark outer band.
Then there are the “other” forms. The Dutch Pink Tail is “an aquarium-selected strain … that has a very yellow tail in place of the usual red,” says Wright Huntley. “It still has the black border, but this combination gives even more [color] contrast. The blue body and yellow unpaired fins with black borders are most striking.”
GUE “blue”, according to some, equates to GUE “blushing.” Supposedly, there is also a xanthic form (golden) available that shows very little black pigment.
To confuse things further, some aquarists contend that the “blushing”, “blue”, and “yellowtail” forms are all the same fish.
How these various “man-made forms actually came about is open to question, but there is some evidence that the “blue” or “blushing” form was fixed by the late Ed Warner. Some question does remain, however, on the genetic makeup of these forms.
“The bluetailed mutation is recessive,” contends Eric Lund. “…. If you cross a blue tailed male to a female of the normal aquarium strain, you should get only males with red tales in the next generation,” and the following generation should be 25% blue tailed.
However, notes Bruce Stallsmith, “If it is indeed purely a questions of genetics that determines one morph or another, it’s almost certainly more than one gene that controls the expression of color…. Even if it is primarily genetics, …[it is possible] that incubation conditions largely determine color, as different parts of the genome are turned on and off during development.”
— G.C.K.A. Newsletter, February 2004 Return to top of page
Nothobranchius sp. Kisaki and Kwaraza
Among the many spectacular Nothobranchius species to come out of Africa over the last few years, Nothobranchius sp. Kisaki TAN 95/9 and its “sister” fish N. sp. Kwaraza TAN 95/14 are perhaps some of the most beautiful. Both were collected from sites in Tanzania by Brian Watters, Ruud Wildekamp and Ian Sainthouse.
N. sp Kisaki TAN 95/5
Collected roughly 60 km south of Morogoro and just north of the Selous Game Reserve, N. sp. Kisaki has basically a blue-green body with red scale edges. The caudal fin is deep red, the pectorals orange-red, and the throat orange. The anal fin is finely banded in blue-green and red, with prominent orange-red “flame-like” extensions to the fin rays, primarily on the front half. Barry Cooper describes the fish as “a rather elongate, slim Notho, with a strong overall reddish orange color that is … intense in the tail [and] … under the throat area.”
N. sp. Kwaraza TAN 95/14
This Notho was collected from the Ruvu River floodplain just west of Dar es Salaam. While undoubtedly the same species as the Kisaki fish, the two populations should not be mixed.
These new Nothos are easily propagated, robust, active, and often aggressive. Unless maintained in “bachelor” male-only tanks, the males will fight viciously; even the females will inflict serious damage on each other. Brian Watters has reported that keeping a number of pairs together in a large tank worked, but that the fish always looked a bit ragged. His best results occurred when keeping the fish in pairs. When kept in small breeding groups of several females to one male, one female usually dominated, forcing removal of the others.
“This is a prolific population,” notes Brian, “and the fry are large, so raising them is no problem.” Incubation of the eggs, typical for Nothos from the lowland Tanzania area, is 2.5 to 4 months. Water conditions for these fish do not seem to be critical. Barry maintains his in hard water (280 ppm TDS), pH about 8.0.
These two fish (the Kisaki and the Kwaraza populations) were one of four new species discovered during the1995 collecting trip. As of late 1996, formal descriptions were being prepared for subsequent publication.
— G.C.K.A. Newsletter, Sept/Oct 1998 Return to top of page
In 1994 Trevor Wood and Johan Ipped collected a beautiful variety of N. kafuensis from Kafue National Park in Zambia. This fish, N. kafuensis Nanzhila River ZMTW 94, combined beauty and fecundity with a quiet and undemanding personality, making it a perfect Notho for those who have only limited time to devote to their maintenance.
Southern Zambia is a dry region drained by the Zambezi River, which forms the border of three nations: Zambia, Zimbabwe, and Botswana. All are economically poor countries that boast a rich diversity of wildlife. Kafue National Park is one of the largest, and one of the oldest, parks in Africa, close to Moramba (Livingston, named for the explorer/missionary), and to Victoria Falls.
The Kafue region has produced at least six varies of N. kafuensis: Chunga, Kayuni State Farm, Kayuni, Lochinvar, Nanzhila River, and Nega Nega. “Caprivi” may be a seventh, depending on geographic and ichthyological definition. N. kafuensis Nanzhila River ZMTW 94, found along the southernmost edge of Kafue National Park, has alternating tiles of rufous and sky blue covering the entire body. The tail ends in a broad band of sky blue. These are small fish, seldom reaching 2 inches. Males are more rotund than females, having a heavier appearance.
These fish seem quite tolerant, breeding successfully in a range of water conditions, and over a wide range of lighting conditions. They eat almost anything provided, from bloodworms and mosquito larvae to dried food, although they seem ignore food that remains at the water surface. They are not particularly shy, and make a good display in a planted tank.
Breeding is by pairs is recommended, rather than by group spawning. Males are not usually hard on females, damage being confined to occasional fin nipping.
Incubation is three to four months (at 72° F), and usually yields fry over two wettings a month apart
Reference: Lamble, David. “Nothobranchius kafuensis (Nanzhila River ZMTW 94).” Killie Dirt, publication of the Canadian Killifish Association, November/December 1998, Volume V, Number 6.
— G.C.K.A. Newsletter, March 2003 Return to top of page
Color Variation in Nothobranchius korthause
One of the pleasures of working with killifish is the wide range of colors and patterns available, some within single species. In many cases, the variances can be explained by divergence, the ultimate isolation of populations in the wild, and by natural genetic drift over time.
Among the Nothobranchius species, N. korthause appears in two extreme forms, yellow and red, plus a variety of transitional forms.
The original description of N. korthause was published by Dr. H. Meinken in Das Aquarium (West Germany) in 1973. Dr. Walter Foresch described spawning the species, using specimens collected by Edith Korthaus on the island of Mafia, East Africa. Gerg Eggers, his wife Christel Kasselmann, and W. Scholl collected both the red and yellow forms of N. korthause from a pool near the Mafia airport. Seven of the dozen males were yellow-brown and five were predominantly red; a red “of great intensity, especially on the upper side of the jaws and on the uncoupled fins.”
Breeding red males to the original females resulted in half of the males being yellow and half red; although most males displayed some degree of red on the fins and bodies.
Experiences with this fish vary, with hatches producing primarily one color or the other, or a mixture of both. The two color forms of N. korthause occur not only together in the wild, but in fry from the same spawn, so obviously factors other than dispersion are in effect. Two appear to be involved: genetics, and incubation conditions.
“If it [color] is indeed purely a questions of genetics,” says Bruce Stallsmith, “it’s almost certainly more than one gene that controls the expression of color…. Even if it is primarily genetics … incubation conditions [may] largely determine color, as different parts of the genome are turned on and off during development. An earlier hatching could produce fish with the yellow morph turned ‘On.’”
“Gestation/growing conditions might determine/affect adult color,” offers Wright Huntley. “Until we know, selectively breeding for a pure color could be an exercise in futility. Selecting for a ‘pure’ red form might not be possible. It might be a matter of controlling diapause conditions or water parameters.
“Or, maybe only the eggs carrying the gene for yellow could complete development entirely submerged.”
“My initial impression is that the strain is a hybrid of yellow and red,” says Roger Sieloff, “and the yellow form is due to a recessive gene. If this is the case, yellow is the pure strain…. Reds can be either pure strains or hybrids. To further complicate matters, females of reds and yellows are probably identical.”
My N. korthause Red, says Barry Cooper, “throw males that range from mostly red to those with a yellow background with reddish bars. Brian Watters has expressed the opinion that the reds currently in the hobby have probably been crossed with the yellows.” In the red form, both the intensity of the color and the patterns can vary.
In its native habitat, N. korthause lives in abnormally soft (0ºdGH) and acid (pH 6.0) water, although they are tolerant of a much wider range of water parameters, and temperatures from 23-29ºC (73-85ºF ). Salt is beneficial, and water changes of up to 50% weekly are encouraged. This habitat often never completely dries out, so egg development takes place either in water or in a moist substrate. For best incubation, keep the spawning peat fairly wet, either in a sealed plastic bag or in a container with water completely covering the surface. Incubation is 14-60 days, depending on temperature.
For breeding, Jaroslav Kadlec reported that he kept a 1-2 cm layer of peat on the bottom of the breeding tank, with a few tufts of Microsorium pteropus and a glass pan for food. Spawning occurred most mornings, with some 60-100 eggs produced weekly. Eggs are about 1mm in size, with a tea-colored tinge.
Water insect larvae are the optimal food, although other live foods are accepted, including tubifex worms and daphnia. Kadlec’s fish refused both dry and artificial foods, although other breeders have had no such problem.
Reference: Kadlac, Jaroslav. “Two Color Variety of Nothobranchius korthause,” 1994.
— G.C.K.A. Newsletter, November 2003 Return to top of page
Nothobranchius palmqvisti – a matter of some confusion
N. palmqvisti is a fairly easy annual African species of killifish that has been a standby in the hobby for some time, in both location-named and aquarium strains.It is, as one aquarist puts it, “a nice little fish, indeed,” being adaptable, active, and pretty. Although it supposedly prefers cool temperatures (68° F), it can live very happily under warmer conditions and makes a good community tank addition as well.
It is also a fish that has been the subject of considerable confusion over the years, particularly with N. foerschi and N. sp. mugeta, and to some extent with N. vosseleri. This confusion ispartly due to human error and partly due to the changing knowledge of Nothobranchius taxonomy.
N. foerschi
Although similar to N. palmqvisti (and for a time actually called N. palmqvisti Dar Es Salaam) N. foerschi has now been determined to be a separate species. Like N. palmqvisti, N. foerschi is an easy Notho, similar to N. guentheri, N. elongatus, and N. rupriprinnis in terms of husbandry.
Nothobranchius sp. mugeta
N. sp. mugeta is a separate and distinctly different species from the interior (high) plains of Tanzania, and is extremely rare in the hobby. Ithas been collected from the exact same location and introduced to the hobby on three separate occasions, the most recent being Barry Cooper’s collection in 1993 (N. sp. mugeta TAN 93/17). The fish has proven difficult to maintain over the long term. If you have N. sp. mugeta in your fishroom and it looks suspiciously like N. palmqvisti, you most likely do have N. palmqvisti, for a misidentified N. palmqvisti has long been circulating in the hobby under the mugeta name. A notable difference between the twois egg size; true N. sp. mugeta eggs are considerably larger than those of N. palmqvisti.
N. vosseleri
N. vosseleri was originally described in 1924, on the basis of a female specimen, and for a long time was regarded as a synonym of N. palmqvisti.
However, in 1995 Brian Watters, Ruud Wildekamp, and Ian Sainthouse collected a number of wild Nothobranchius, among them several that they identified as N. vosseleri. Brought into the hobby from this collecting venture were: N. vosseleri Korogwe North TAN 95/17, N. vosseleri Korogwe South TAN 95/18, and N. vosseleri Mombo TAN 95/19.
This is, reports Brian Watters, a fairly easy species to maintain and to breed. Populations are prolific, and have a relatively short incubation time of 2-4 months.
— G.C.K.A. Newsletter, October 1997 Return to top of page
The genus Pachypanchax is comprised of three species – P. playfairii, P. omalonotus and P. sakaramyi. Several other populations may or may not be undescribed species. P. playfairii is found on the Seychelles Islands and Zanzibar; the other two are found on the island of Madagascar.
Pachypanchax playfairii (Guenther 1886) has been known in the hobby for almost 80 years, having been first imported into Germany in 1924. It is, however, a species that comes and goes in the hobby, since it is not “new,” and is not as flashy as fish from many of the other killifish genera.
Males have a yellow base color with red dots on the body and black edging on the tail. Females are plainer and have a dark spot at the base of the dorsal fin. P. playfairii, which may reach 4″, are fairly easy to keep and will do quite well in average water. They will eat most foods, and should not be trusted with smaller fish. Under certain conditions, the scales of the male fish stand out from the body, making the fish appear to be suffering from “dropsy.” This condition, which often appears only on the back, is normal for the species.
P. omanolotus (Dumeril 1861) was first imported into Europe about 1953. Their common name, the Powder Blue Panchax, gives an indication of its colors. Males have more intense color, and have longer fins than females. There are two strains currently available in the hobby, an aquarium strain, and “Nosy Be”, named for a small island off the NW coast of Madagascar. Several other populations of this fish exist along the northwest coastal area of Madagascar; these may or may not turn out to be undescribed species. Like P. playfairii, P. omanolotus males are fairly aggressive to the females. They are reported to breed readily.
The third species, P. sakaramyi, is found only in Madagascar. Males are deep yellow-orange with blue on the back and dark fin edgings. The color is said to intensify if the fish are kept in direct sunlight. Females are essentially olive-brown. P. sakaramyi grow to the same general size as the other two species, and share many of the same characteristics, including the aggressiveness of the males. According to some, best results occur when the sexes are kept together in a well-planted species tank.
Breeding all three species is fairly simple, although the males are noted for their aggressiveness when breeding. Best success is often achieved by keeping the sexes separate and bringing them together only for spawning. Provide plenty of bushy plants and dense mops for egg-laying and cover for the females. The eggs are adhesive, and can either be picked from the mops or the entire mop incubated for the 12 days or so required for development. Fry are fairly large, and can immediately take baby brine shrimp and microworms. They grow steadily, and should be sorted regularly by size, since older, larger fry will often eat their younger siblings.
Reference: McFarlane, Paul. “Pachypanchax.” Hamilton & District Aquarium Society Monthly Bulletin (Canada), June 2002. Reprinted in Aqua News, newsletter of the Minnesota Aquarium Society, July/August 2003.
— G.C.K.A. Newsletter, July 2005 Return to top of page
Pachypanchax omanolotus Nosy Be
By Cathy Carney
While Pachypanchax omolanotus of one form or another has been in the hobby for decades, it is currently a species of concern for the Killifish Conservation Committee of the American Killifish Association (AKA). As with many other species from Madagascar, it faces habitat destruction due to human action, and some populations of this species are either endangered or extinct in the wild. Further, although it has adapted well to life in aquariums, it is not currently widely available in the hobby.
Pachypanchax omolanotus is a medium to large killifish, with adults reaching approximately four inches, although they will breed when much smaller. They are a top-dwelling, plant spawning, non-annual killifish, equally at home in tanks as small as 10 gallons for a pair or schooling in a warm lily pond. Tolerant of a fairly wide range of temperatures, they seem to be healthiest and breed best with temperatures of 75-80F.
The Nosy Be population is not the flashiest of killifish — males are “gun metal gray” over most of the bodies with some flashes of iridescence, and females tend to be pale fish, olive shading to gold or yellow orange on the fins. The fish are torpedo shaped, with dorsal and anal fins set far back on the body. They can move quickly when needed and often act as pike-like ambush predators when in pond settings, hovering under a floating leaf, then dashing out to grab anything that hits the water.
Nosy Be’s are easily maintained in aquariums. They are not picky about water conditions or foods in most cases. Even in minimal conditions — a planted 10 gallon tank, partial water changes, and flake food — some fry will grow up with the parents. Add more space, more plants, and live foods, and many more fry will appear. However, as with many other killifish, juveniles and and subadults will eat their younger siblings, so it is best to incubate eggs and raise fry separately if the goal is to raise a large number of these fish.
To breed these fish, start with healthy, well fed parents. They are heavy eaters, so be prepared to feed well and often. In keeping with their upturned mouths and other top-dwelling adaptations, they prefer foods that float at the surface, such as flake food or wingless fruit flies. Food in the water column, such as daphnia and brine shrimp, are also eaten, but food on the bottom is ignored for the most part.
Males can be hard drivers, so offer cover for the female by using a heavily planted tank or several spawning mops. Spawning these fish in trios or harems also can work well, although there will be some egg predation from the non-spawning females.
Eggs are about one millimeter in diameter and amber in color. Fertile eggs look and feel like tiny amber plastic beads. Clear or pale eggs are often infertile and develop fungus in the hatching container. The eggs are typically found toward the top of spawning mops or in floating plants and can be removed easily to smaller containers of tank water for incubation. Deli containers containing half an inch of tank water and a few sprigs of Java moss work well for this. The eggs do not seem to be light sensitive, and hatch in approximately 14 days, depending on temperature.
The fry are tiny upon hatching, and need a few days with infusoria or other tiny foods before graduating to baby brine shrimp. They are also quite sensitive to deteriorating or unstable water conditions, so the rearing container should be larger than normal. Deli contains, shoeboxes and other small containers don’t work well in many cases, but 2-1/2 gallon tanks or 2 gallon pickle jars of tank water with Java moss, riccia, and ramshorn snails work well for up to two dozen fry for the first few weeks. Move the fry from the hatching container to the rearing container using an eyedropper or pipette.
Once in the rearing container, feed daily with finely ground live foods. The fry won’t eat it all at first, but the snails will, and the infusoria in the tank will feed off of the snails’ droppings. The fry grow quickly and will start to eat baby brine shrimp, tiny daphnia, and finely ground flake food within a week or two. They become more tolerant of water conditions as they grow, and small partial water changes can be started after they reach the two week mark.
Once through the critical first few weeks the juveniles become nearly indestructible. Like the adults, they are heavy feeders, and will eat nearly anything they can swallow as long as it is on the surface or in the water column. As with the adults, keep the tank covered and provide floating plants to reduce jumpiness.
Juvenile fish may start to sex out when very small, sometimes at an inch or less in length. Males will show smoky gray colors on the body and some iridescence in the fins first, then develop points to the dorsal and anal fins as they continue to grow. At this point there may be some displaying and sparring among the fish as they establish dominance hierarchies, but usually injuries are minor or non-existent. Providing a planted tank with hiding places at this time helps to reduce aggression.
As with other killifish, Nosy Be’s will start producing eggs once they develop adult coloration, but the majority will be infertile. Fertility will improve as the fish reach adult size. A healthy pair of adult Pachypanchax omonolatus should produce fertile eggs for at least 12 to 18 months, and may live for two or three years or longer.
— G.C.K.A. Newsletter, January 2004 Return to top of page
Racovia brevis – an interesting annual
Although not often seen in the hobby, Rachovia brevis is one of the nicer South American annual killifish, being reasonably pretty, not highly aggressive, and fairly easy to breed.
Native to northern Colombia and northwest Venezuela in the drainage area of the Rio Magdalena and neighboring Atlantic tributaries, R. brevis requires conditions similar to those for the Cynolebias fish – neutral to slightly acid pH, medium hardness, and temperatures of 24-26ºC (76-79ºF), although they can take warmer water. A species tank with plants and a peat bottom is recommended.
The 3″ males, which are larger than the females, show a range of coloration. The base body color is generally a grayish-brown, often with a vague vertical zig-zag pattern, that shows a flush of yellow-gold just behind the head, changing to a pale blue on the caudal peduncle. The anal and dorsal fins are pointed and may be flushed with orange. The tail has elongated tips, and both the anal fin and tail may have narrow margins of yellow or orange. Females are smaller, plainer, have more rounded fins and a narrower caudal peduncle. Life expectancy is up to a year, but the species is noted for a sharp fertility drop with age.
These fish will do well on a varied diet of live foods – blackworms, brine shrimp, fruit flies, grindal and white worms, etc. – with some flake foods. R. brevis is a peat spawner, sometimes diving into the substrate. Breeding is accomplished over a deep peat layer. “I usually breed them in a 2 gal. tank with a plastic freezer box, hole cut in the top, with about an inch of peat,” says Dr. Dan Nielsen. He uses marbles to keep the box down. The eggs are quite hardy, and can take cooler temperatures that the adult fish. Incubation time is approximately 5 months at 22ºC (72ºF), 4 months at 25-27ºC (77-80ºF).
The hatching fry are large enough to take brine shrimp nauplii, and grow rapidly.
Reference Baensch, Hans A., and Dr. Rudiger Riehl. Baensch Aquarium Atlas 2. Mergus, Germany, 1997, p. 672-3.
— G.C.K.A. Newsletter, June 2003 Return to top of page
Recently a new fish has appeared on the list of killifish, Renova oscari. This new genus and new species of annual rivulid killifish was first described in the Icthyological Journal of Freshwater Fishes 1995, but has been in the hobby for some time as Moema sp. Isla Raton RDB 92/22. Representative specimens were collected in a temporary pool on Isla Raton, Upper Rio Orinoco, Amazonas State, Venezuela. Collected from the same pool were Pterolebias xiphophorus, Terranatos dolichopterus, and Rivulus species.
Males, which may grow to 4 inches, have a green/blue body with five to seven lateral red stripes that begin behind the dorsal fin, small pelvic fins, and long extensions of the central caudal rays. Females, which look like typical “big rivulus”, may or may not have a “rivulus spot.”
Maintenance notes: water 25-26 deg. C temperature, pH 6.5. Peat spawning, with an incubation period of 5-7 months. Although the eggs are small (1.25mm), amber in color and hard to see in the peat, the fry are fairly large at hatching (baby guppy size) and can readily take small live foods. Renova oscari appears to be a fairly easy, relatively prolific fish.
— G.C.K.A. Newsletter, October 1996 Return to top of page
Although usually thought of as “one of those ugly brown fish,” R. cylindraceus was for some time confused with the hermaphroditic R. marmoratus. However, it was eventually determined to be a species in its own right
Hailing from Cuba, this fairly plain fish frequents the freshwater streams that feed into bays and rivers. Although they can tolerate salt in the aquarium, in their native habitat they avoid brackish water for the fresher streams, leaving the saltier habitats to R. marmoratus.
Although usually sporting a colorful pattern of … brown … R. cylindraceus has surprised some researchers, according to Bruce Turner, who maintained some as comparative species to R. marmoratus, with which he was working in the lab. “I discovered … quite by accident, that when raised ab ovo (from the egg) on a diet primarily of brine shrimp, [you could just] watch the reds and oranges come out. The color is quite strong and rather impressive.” A technician had raised some R. cylindraceus fry on the diet used for the R. marmoratus; the males of the next generation were impressive.
Bruce reports that he kept two pair in a two liter beaker on a lab bench (with a floating mop) in full room light for several months, and they attracted a lot of attention from visitors.
Two other strains of this species have been seen in the hobby in recent years, a dark green strain supposedly from Isle of Pines, and a “black” strain referred to as “Al Castro.”
– GCKA Newsletter, February 1998 Return to top of page
Rivulus xiphidiusa perennial favorite from those “ugly brown fishes”
Many killikeepers disparage the Rivulus species, scoffing at their lack of color and eye appeal. However, one species has continued to remain popular among killi fanciers – Rivulus xiphidius. Although long popular, it is a species that many breeders find problematic.
R. xiphidius was first described by Huber in 1979 from fish collected in Matoury, the District of Cayenne, in northern French Guiana. The species is most notable for its distinct, neon-like coloration. Although the females are typical “killi drab,” being tan or pale brown with a longitudinal darker stripe, the adult males have a bright coppery bronze body color, slashed by a light blue to turquoise stripe that begins just behind the eye and runs through the caudal fin. Below it is a band of dark to navy blue, followed by another, narrower light blue band that often begins at the lower lip and runs through the anal fin and the tail. The anal and caudal fins have an outer edging of copper. The specific shades of blue and their intensities may vary with the individual fish, and with the collection location.
Although regarded as a “difficult” species, a number of people have successfully bred R. xiphidius.
In general, recommendations include soft water, very good water quality (water changes weekly, or more often), a temperature of 72-74° F, and lots of plants.
“I have been keeping R. xiphidius for the last half dozen years,” says Charles Harrison. He uses 5 gallon tanks with about half the space filled with yarn mops. “I don’t usually pick eggs, but net out three to five fry a week.” He makes total water changes weekly, using his local (St. Louis) tap water, aged at least overnight with an airstone/bubbler. “A little chlorine in the water doesn’t hurt, it helps to keep the bacteria level down, and never bothers the fish.”
Ted Klotz raised R. xiphidius in rainwater, “exclusively.” Sex ratio was 2:1 female to male. “In using rainwater,” he cautions, “you need to watch the pH. With no buffering capabilities, [it] … can crash overnight. A permanent setup with plants negates this in some way. Keeping them on the cool side (70-72ºF) didn’t seem to bother them much either.”
Richard Sexton recommends pH 6-7, hardness 80-150 ppm, temperature about 76-78° F. “Just be patient with the fish. Eventually, over time, fish will produce a decent sex ratio.”
Adrian Heimann succeeded with R. xiphidius using soft water (10-20 ppm tds) and the addition of peat tea – “no actual peat, which lowers the pH somewhat.” Twice weekly water changes kept the pH from dropping too precipitously. He kept the tank well filled with Java Moss, and used top spawning mops that reached down into it. “They should do well with fry hatching and growing in the breeding tank,” says Adrian. “Move the fry when they seem big enough; maturing males will often kill other males. They’re slow growers.”
You might also occasionally siphon the mulm from the bottom of the tank and carefully inspect for eggs; they aren’t very adhesive and often end up on the bottom. Fry will also hide in the mops. One breeder found that he got more fry by simply removing the mop and shaking it vigorously into a bucket than he did by picking eggs.
— G.C.K.A. Newsletter, June 2002 Return to top of page
Rivulus xiphidius – a beautiful favorite
We all know that impulse buying of fish is a mistake!
That didn’t stop me from buying my first pair of Rivulus xiphidius. I saw them and just had to have them. I’d never had Rivulus before. I’d not kept soft-water killifish before. But I was seduced; the shape and the color of those beautiful little fish absolutely captivated me. Discovering the species was a revelation; buying them was a flagrant abuse of the rules of common sense, but I went home with two young pair.
My first acquisition of R. xiphidius several years ago may have been on impulse, but my second (and more successful) experience with them was quite by intent.
Most killikeepers know of R. xiphidius, the Blue-stripe Killie. Native to South America, they are found in slow moving or still water branches of flowing streams in the coastal areas of French Guiana, Guiana, and Surinam. These waters usually have a light colored sand substrate covered by vegetative debris, resulting in relatively acidic water with almost no measurable hardness. R. xiphidius is often found sympatically with R. geayi. Occasionally the tetra Copeina arnoldi is found in the same habitat, or R. agilae, R.. cf. urophthalmas, or R.. holmiae.
I set up a 5 gallon species tank using 2 gallons of well aged water from an already established tank (pH of about 6.4), a gallon of rainwater, and the balance conditioned tap water. Some breeders highly recommend keeping these fish in larger quarters, with low water levels, since the fish seem more comfortable. For substrate I added a thin layer of gravel; a couple of handsful of peat, both to provide cover on the bottom and to aid the water’s buffering ability; a slow running well-established sponge filter; and a generous clump of Java Moss. Since this species prefers some warmth and my fishroom tends to be cool during the fall and winter (68-72° F) I also outfitted the tank with a heater, set to about 74° F, as well as a glass cover.
This is definitely a fish for subdued lighting. Placed into surroundings where it is not at ease, or with too much light, and the colors wash out.
R. xiphidius is one of the more colorful of the Rivulus family. Males sport an overall light copper-brass color with a dark blue diagonal stripe that begins behind the eye and extends on through the lower end of the tail. This is bordered, in the anal fin and tail, by bands of bright turquoise blue. The bottom edge of the tail and the anal fin are bright coppery orange. Adult females are a pale golden brown, with a dark stripe that starts near the snout and extends the length of the body to the tail.
No matter the number of adults in the tank, I rarely saw more than one or two of the fish at one time. They tend to be quiet and shy in nature, more inclined to laze among the plants and cover than to swim out in the open. Occasionally I would see them moving, but usually they appeared only when being fed, and then slowly and with caution.
Feeding was no problem. They readily accepted every food offered: newly hatched brine shrimp nauplii, locally purchased adult brine shrimp; mosquito larvae; cultured white worms; and whatever other small live foods I could collect in my garden. Every other feeding I offered them the usual dry foods/flakes/frozen foods assortment that I feed my other fish.
They had settled in and were eating well, but would they breed? I’d heard that R. xiphidius was a “difficult” fish, but I had to try. I kept the proportion of live foods in their diet high and provided them with a floating spawning mop that extended from the water surface to the substrate.
For some weeks regular checks of the spawning mop yielded nothing. During this time I was careful to not disturb the fish, including easing off on my schedule of regular water changes. R. xiphidius seems to prefer “dirty” water, at least several weeks old, for spawning.
Then – magically – one single, very large, amber colored egg. The egg was nearly double the size of the eggs laid by my Aphyosemion mirable- an incredibly large egg for such a small fish as R. xiphidius. I collected the egg, placed it into a small glass baby food jar about 1/3 filled with conditioned water just tinted yellow with Acriflavine, and set it aside. Over the next couple of weeks I collected a total of eight eggs, most but not all in the upper reaches of the mop.
Breeders report having experienced problems with egg development in this species- eggs hatching too early, disintegrating completely, or being consumed by fungus. Bob Tornatore reports success with the species by storing only small groups of eggs (20 maximum) together, and by washing them every day (100% water change) until they eye up. He then hatches the eggs and raises the fry in water from the parents’ tank. Others have incubated the eggs for two weeks on wet peat, then added an inch of water to the container until hatching occurs.
I keep my water and wet peat incubating eggs in labeled containers in a box on a bookshelf in my fishroom. There they receive limited indirect light from the room and were subject to temperature variations of 68 to 76° F, depending on the ambient house temperature. Several times a week I checked the contents of each container and removed any diseased or disintegrating eggs. When necessary, I replaced part or most of the water in the hatching containers.
It took nearly eight weeks for the R. xiphidius eggs to hatch, although others have had hatches occur after much shorter periods. The eggs darkened considerably in color during incubation, to a clear, rich, dark amber, with the embryo clearly visible.
As the eggs aged, the outer surface roughened and appeared to shed “flakes,” leaving them with a surface appearance similar to peeling paint. These flakes of shed material lay on the bottom of the hatching container, but seemed to cause no problems. There was no sign of deterioration of the eggs themselves during the incubation period, or of the water turning foul, so I left the eggs alone.
The morning I found a newly hatched fry I immediately moved it (using an eyedropper) into a plastic shoebox half filled with water from the parents’ tank, with a clump of Java Moss. Although clearly visible from the side in the hatching container, the fry “disappeared” in the grow-out container- they are nearly transparent, and practically invisible from above. As the rest of the eggs hatched, I moved them into the grow-out container. Raising the fry was not difficult although I found that they grow very slowly.
I start most fry out on a combination of Liquifry, baby brine shrimp, and microworms. With the natural microflora/fauna of the Java Moss and regular partial water changes, they tend to develop quite well. When they have gained some size I transfer the fry to larger growout containers or 5 gallon tanks.
My only distress was that it was so hard to see them! In order to assure myself that they still were present in the container, I would have to completely remove the Java Moss and pour out most of the water (through a net, of course). Even then I would have to look closely to find them. Most fry are dark, move around somewhat, and show up clearly; R. xiphidius fry are light in color and tend to hover nearly motionless in one place.
A problem often encountered with R. xiphidius is skewed sex ratios. There is some evidence that the water hardness and temperature directly affect the sex ratios of the fry. There is also a theory (and some research evidence extant) indicating that hormone production by the dominant young male causes the other males to become submissive, and perhaps keeps “would be” females from developing. This has been at least partially borne out by experiments that separate the fry into small containers, each with two fry. When raised together, two juvenile fish often resulted in one adult pair. Best results with R. xiphidius, producing fairly even sex ratios, seems to occur using very soft water (hardness near zero), with a pH between 6.0 and 6.5, and a temperature of 72-75° F.
The sex ratio in my fry seems to be fairly good when grown out in softwater with lots of Hornwort and Java Moss.
Difficult? I don’t really think so. Fussy, perhaps. If they have received a “difficult” reputation, it may be because they are fairly shy and not terribly prolific. If I was lucky, I got three or four eggs a week from a spawning pair. But they can be maintained, and propagated. In my opinion having these little jewels around to admire is well worth the effort required.
Resources: Schneider, Peter. “The Blue-Striped Killifish, Rivulus xiphidius. Tropical Fish Hobbyist, July 1996, pp. 84-89
— G.C.K.A. Newsletter, February 2005 Return to top of page
Page copyright G.C.K.A.and Donna M. Recktenwalt 1996-2005. Return to G.C.K.A. Home Page.