(or How I Got Started with killifish)
by Tony Pinto
Copyright Tony Pinto (reprinted with permission from the author)
A brilliant flash of green, red and yellow was all I saw as the fish dashed into the Java moss in the glass tank. It was my first encounter with killifish and I was hooked! I had become captivated by the antics of a pair of Aphyosemion striatum "Cape Esterias" which were spawning in a small tank in the basement of one of my favorite aquarium stores in London, England, early in the spring of 1981; I gave in to the temptation of buying the pair, took them home and successfully spawned then in the hard London tap water. I was delighted to raise several generations of fry from the parents. They were my introduction to the exciting world of killifish - as a result, I joined the British Killifish Association (BKA). After I had mastered the basic skills for keeping and breeding these easier killies - I moved on to breeding such beauties as Cynolebias nigripinnis and even the stunning Nothbranchius rachovii!
But enough said for now about the other species - from my experience, Aphyosemion striatum are an excellent fish for a beginner who is interested in moving on from the livebearers to the colorful killifish and who might not have a lot of tank room for experimentation - it is relatively easy to acquire a pair of this fish at killifish auctions and once acquired, they are quite easy to feed and maintain (I have managed to get them to take flake and frozen food although they prefer live foods like grindal worms, small whiteworms, chopped blackworms etc.); in addition, they are very easy to breed and can be (in my experience) quite prolific too - the fry aren't difficult to raise. So, a beginner who wants to try his/her hand with top spawning killies can't really go wrong in choosing this species. I would rate them to be as good a beginner's killifish as the Fundulopanchax gardneri species that are often found at aquarium auctions (and occasionally in stores). The fact that I was successful in raising fry in the hard, alkaline London tap water (while soft water is the recommendation for most killifish species originating from the rainforest areas) speaks volumes about the adaptability of this species and of killifish in general (however, I would not recommend hard water for those species whose natural habitat is naturally soft and acid water).
The fish originate from the small brooks and streams flowing through coastal rainforests in Equatorial Guinea and northwest Gabon. Other killifish species found with Aph. striatum are Epiplatys infrafasciatus (formerly Epiplatys sexfasciatus), Epiplatys singa and Aph. microphtalmum. Other members of the Aphyosemion striatum group include Aphyosemion gabunense (with it's subspecies gabunense gabuense, gabunense marginatum and gabunense boehmi), Aphyosemion primigenium, Aphyosemion micropthalmum and the beautiful Aphyosemion exigoideum. Most of these species, with the possible exception of Aphyosemion micropthalmum, are readily available in the killifish hobby. Populations of Aphyosemion striatum currently in the hobby include fish originating from Libereville, Lambarene and Cape Esterias. European killifish collectors visiting Gabon seem to collect these fish regularly and so, the aquarium hobby is fortunate in having quite a few populations of this species circulating through hobbyists' tanks.
Like most Aphyosemion species, the males of the species are more colorful being basically a grass green with four or five red stripes running horizontally across the body and ending near the root of the caudal fin. The unpaired fins are green with red markings - the caudal is peppered with red spots and the upper edge is red-black while the lower edge is yellow. In older males the upper edge of the caudal fin grows a small extension to around 3 mm. The dorsal has a red sub marginal band and a red edge, while the anal has a yellow sub marginal band and by a red edge. The pectoral fins are edged with yellow or orange. Females are a dull gray to brown with colorless fins - sometimes the dorsal shows a black edge, particularly if the females decide to display to males. Males typically grow to around 5 cm while females might remain a 1 cm or so smaller.
These fish can be can be maintained in community aquaria as I have found them to be quite peaceful to other species of similar size although males can be quite intolerant and will bully one another. As an experiment, I once placed a couple of pairs of this species in a planted community tank containing small, non aggressive Asian barbs (i.e. the five banded bard B. pentazona), Rasboras (harlequins - R. hetermorpha, the dwarf rasbora - R. maculata) and various South American tetras (cardinals / glowlights) and witnessed that the dominant male would chase the less dominant one without mercy whenever it came into view. And no, I did not see or raise any fry under these conditions. The fish might be shy initially, but they overcome this shyness and will approach the front of the tank when they think the aquarist has a meal for them - this is completely different from the Aph. elegans types whose behavior might best be described as skittish! A tank cover is a must as these fish are good jumpers (in common with other plant spawning killies) and it is not unusual to find that your fish have jumped out and dried to "crisped fish" if you have fed them and forgotten to replace the tank cover. This is behavior that killies seem to be very fond of, particularly the top spawners! So, it pays to be vigilant and avoid losing your beautiful pets!
If the intention of the aquarist is to breed the fish and raise fry, it is best to keep these in a single species tank - this is a necessity in the case of a lot of other plant spawning killies too. For breeding a well conditioned and well fed pair is maintained in a single species tank - which, for me, is usually a 5 gallon tank with lots of Java moss and a perhaps a sponge filter in a corner of the tank - eggs will be laid in the moss and fry will appear spontanteously. I have tried substituting Java moss with washed peat fiber and can say that the results have been very good - the only issue is that occasionally the peat tends to change the color of the water from clear to amber. This appears to improve the color and health of the fish. Another tried and tested alternative to having plants in the aquarium is to supply an acrylic wool mop for the fish to spawn in. There are several books on killies (ref. 3, 4) which provide the basic instructions to the beginner on making a mop. I have tried floating mops (the mop attached to a piece of Styrofoam) and bottom mops and have collected more eggs near the top of the mops than the bottom one in the case of this species. Eggs numbers vary depending on the health of the fish - the aquarist should check that the females do not have ripped fins or become "hollow bellied" as male Aph. striatum (in common with other killies) are aggressive and can be very hard drivers.
For the aquarist who relishes the experience and excitement of collecting eggs and watching them develop and hatch, it is certainly possible to do this with this species as the eggs possess a hard shell, which is not easy broken. Fertile eggs are round and clear with a diameter of around 1 mm- they develop continuously in water and hatch in approximately 2 weeks. They are relatively easy to detect when searching with fingers in the Java moss. The only drawback to this method of egg collection is that it can be quite time consuming. The eggs can be stored in either a small petri dish or in a clear plastic vial which allows the aquarist to monitor the embryo development. Unfertilized eggs turn white in a day or two and can immediately be removed from the container - otherwise, they develop fungus which rapidly attacks the good eggs, and kill off the developing fry. A variation of the method is to put the eggs in slightly damp peat in a petri dish or vial for around 2 or 3 weeks at 72 - 75 oF. Then I put the eggs into water and hatching usually happens within a day or two. Of course, using this method it is not possible to see the embryos after around 10 -12 days as the eggs appear to be black as development proceeds and the aquarist might think that the eggs have all turned bad.
The method I have had most success with for obtaining fry consists of simply feeding the parents, siphoning the detrius from the bottom of the tank and changing around 10% of the water every week and let the fry swim in the tank with their parents, when they appear - they appear as little gray to black slivers at water surface waiting for any infusorians and small microscopic organisms to come their way. They tend to be very shy at first and dash at the first sign of danger - real or imagined. But they consume microworms and newly hatched brine shrimp from the end of the first week and grow quite rapidly (for plant spawning killifish). Interestingly enough, once the larger fry have reached a size of around inch, it is very rare to spot any of their younger brothers or sisters as the older fry develop cannibalistic tendencies. At this stage I usually move the older fry to other tanks to raise more fry (if I have enough tank space!). The fry show female coloration and I am able to sex them out at around 2 to 3 months with reasonable certainty as males start to color up- they develop the green on the flanks, the characteristic red horizontal stripes and the yellow and red markings on the unpaired fins while the females remain a dull gray. In my experience, some pairs of Aph. striatum appear to produce more males than females - I've had a few occasions when I have raised a tankful of pretty males and not a single female. I am not sure what causes this but perhaps food and pH are factors which trigger this.
To sum up then - this is a very pretty fish which should certainly be more popular and widespread. My original pair lived to be 2 plus years old when I lost them. It was a sad day when I lost them but by that time I had two tanks of fish which was more than a few fish to work with! ...and Aphyosemion striatum continue to be one of my favorite killies.
1. Atlas of Killifishes of the Old World by Jorgen Scheel, published by TFH publications, 1990.
2. Colour Atlas of Cyprinodonts of the Rain forests of Tropical Africa by A.C. Radda and E. Purzl, published by O. Hoffmann-Verlag, 1987.
3. Breeding Killifishes by Marshall Ostrow, published by TFH publications, 1981.
4. Killifish: A Complete Pet Owner's Manual by Steffen Hellner, published by Barrons Educational Series, 1990.
© Tony Pinto