Meaning of Name |
From 'exiguus' meaning small. | ||||||||||||||||||||||||||||
First Description |
Boulenger G.A. 1911. Descriptions of New African Cyprinodont Fishes. Ann. & Mag. Nat. History: series 2 (8) : pages 260-268. | ||||||||||||||||||||||||||||
Size |
4cm | ||||||||||||||||||||||||||||
Meristics |
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Karyotype |
n = 18, A = 36 (Scheel 1968, 1974, 1990). n = 18-20 in some publications. | ||||||||||||||||||||||||||||
Sub-Genus |
Kathetys | ||||||||||||||||||||||||||||
Group |
exiguum | ||||||||||||||||||||||||||||
Synonyms |
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Populations
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Ayén - South of Djoum on the border with Gabon. Grell & Eberl (1991) collected them & also found A.kunzi. The following day they collected between Ménguém & Mvengué & found A.exiguum with A.batesii. CGE 91 / 10 - Stream 24 kms west of Ménguémé & 2 kms east of Ngomedzap, south Cameroon. See photo (Grell) BKA newsletter No.458, November 2003. p137. CGE 91 / 14 - Stream, 11·7 kms south of Mbalmayo. See photo (Grell) BKA newsletter No.458, November 2003. p136. GBHL 86 / 8 - Collected by Bardin, Houdu & Lombard in 1986 110 kms from Oyém on the road to Nsak, Ntem drainage. As the crow flies this is only a few kms from the Cameroon border. Thought to have been lost in the hobby. Passaro & Eberl visited the location in 1994 but no fish were introduced to the hobby. GKCAR 90 / 8 - See photo (Grell) BKA newsletter No.458, November 2003. p139. RPC (GJH)(JH) 79 / 154 - Collected by J.H.Huber in 1979. Situated 29 kms south of the turn off on the road to Garabinzam. This collection was not brought back live. Sangmelima - Towards the end of 1972
this population was donated to the BKA by Manchester killie keepers.
Zoatupsi -
Zoetele -
Thys 1964 - Near Melen-Olezoa Scheel 1966 - 23 km north of Sangmélima Clausen 1966 - 18 km east of Olounou towards Djoum Radda 1971 - 8 km south of Sangmélima Houdu 1986 - 110 km NE Oyem to Nsak Bouisson 2001 - Memgbwa
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Type Locality |
Collected by Bates in the Nyong River, Southeastern Cameroon. | ||||||||||||||||||||||||||||
Distribution |
Southern Cameroon on the Inland Plateau, in the Boumba, Boumw, Dja, Lobo, Nyong & upper Sanaga River drainages. This range extends to the south into northern Congo, northern Gabon in the upper Ivindo basin & the southwestern Central African Republic. | ||||||||||||||||||||||||||||
Habitat |
Forested streams & pools in mainly stagnant, swampy areas. They prefer to inhabit clearings where vegetation overhangs the water banks. Scheel found them in Raffia swamps where there was only sufficient light to support the growth of algae. He measured the water at 0.1 - 1.5 German degrees hardness, pH 4.2 - 6.5. Scheel reports in ROTOW 1 that he collected them with A.batesii during the dry season. A.exiguum was found to be breeding at this time. Sympatric sp. include E.sangmelinensis, A.obscurum, A.batesii, A.cameronense, Lac.camerunensis Biotope
of A.exiguum & A.cameronense
near Zoetele, Cameroon | ||||||||||||||||||||||||||||
Distinguishing Characteristics | Distinguished from A.elberti by its squarer looking (less flared) caudal fin. The dorsal fin can become quite long & pointed in older males. Their is a tendancy for the caudal fin to have a thick red submarginal band from the upper caudal peduncle then vertically down the back of the fin returning to the lower caudal peduncle. This is not seen in every population & this characteristic can also be seen in certain populations of A.elberti. | ||||||||||||||||||||||||||||
Colour/Pattern Variability | Fairly high. | ||||||||||||||||||||||||||||
History |
Discovered by G.L.Bates in the Nyong River (Cameroon). This single specimen (a male) was used to describe the species as Haplochilus exiguus by Boulenger in 1911. Boulenger gives the following collectors / locations in his 1915 Catalogue.
In 1966 Scheel collected them in wooded areas of the inland plateau of eastern Cameroon. In the 1960's Dr.Benigno Roman of Madrid received collections from Equatorial Guinea. Results of his studies were published in'Los Peces de Rio Muni'. Barcelona. 1971. p165. Mention is made in the book of a location 'Cuenca del Miyogo, afl Monyoga el 10/8/1966'. This means an area of Miyogo in a stream/water course of the Monyoga drainage. Known to be in the BKA in December 1966. These were sent by Leif Christensen of Denmark & were breeding at one & a half inches. They were described as having a 'yellow body with a pattern of reds & browns'. Also came into the UK through the BKA Species Import Committee late 1968 & June 1974. Collected by Roger Langdon north of Sangmelima (Cameroon) in 1971. Scheel collected at Lolodorf in 1974. Rod Roberts along with 7 Austrians & a Frenchman collected in Cameroon in July 1983 (K/N 228). Rod's group also comprised Ed Pürzl & Hubert Peturka. A population was caught at Febmimbang. This population was distributed in the UK in limited numbers. In January 1986 P.Wagner & R.Wendel found this species in Gabon for the first time. History of the synonymous A.jacobi. Jacob, in 1928, collected 4 specimens from the Lokundje River, Lolodorf, southern Cameroon. This locality is 440 metres above sea level. These were examined by Ahl & used to name the species Panchax jacobi. History of the synonymous A.jaundensis. Ahl described Panchax jaundensis in 1924 from a single female collected at Jaunde, east Cameroon. Holly studied the type material in 1930 & changed some of Ahl's data. History of the synonymous Panchax loboanus. Ahl, in 1924, used a single specimen collected by Schreiner at the upper reaches of the Lobo River, Sangmelima, southern Cameroon. In 1930 Holly re-examined the type specimen & changed some of the meristic data given by Ahl. History of the synonymous Panchax loloensis. Jacobs caught 4 specimens at Lolodorf, eastern Cameroon which Ahl used in 1928 to describe the species. Lolodork can be found on the Lokundje River north of Kribi & south of the Nyong River. Lolodorf is 440 metres above sea level. | ||||||||||||||||||||||||||||
Breeding Notes |
When
first imported to the hobby very few pairs were available & these produced
few fish for distribution. The advent of breeding this sp. in permanent setups
however produced a greater number of fish for distribution. I have found this sp. a little more difficult to spawn & never had more than a few eggs. A dark tank should be used for breeding. Reports suggest that a water change using clean rain water has induced the fish to spawn, although they are not a prolific sp. Eggs are laid mainly in floating mops or vegetation & take 2-3 weeks to hatch. Water incubation is around 10-15 days. Parents are reportedly avid egg eaters (some reports state they are not, & fry go unmolested). Fry can be hard to rear & do best in water from the parents tank which is shallow (2-3"). Fry are small & do best on infusoria for a few days. Water changes should be carried out with extreme caution. Old water would seem to be the key to success with raising this sp. They seemed to dislike harder water of DH10+. Fry are slow to mature & start to sex out in 3-4 months but full sexual maturity is not attained until they reach around 8 months.. In BKA newsletter No.70, June 1971 a dark breeding tank was used with a layer of peat on the base & floating plants. A handful of rotting sphragnum moss was also added. Water temperature 72-74° F, pH 6·6-6·8, DH 2-7. Collecting eggs from mops was not successful as they turned fungussed. It was found more successful to breed them in a natural setup & let fry hatch in the parents tank. One report in BKA newsletter
No.95, July 1973 by Dr.R.B.Ingersoll concerned the breeding of the Roger Langton
collection of 1971 from north of Sangmelima. The brood fish were F2 generation.
The fish were maintained in a bare 5 gallon (US) tank filtered with a corner box
filter. Temperature was 21-23°C, pH 6·2-6·4, DH 2·5.
The tank was kept dark with light excluded from the back & sides. An
article by J.Willerton in BKA newsletter No.113, January 1975 gave the following
breeding information - Aged deionised water was used with the addition of similar
water which had been standing over peat for some time. The mixed water turned
to a 'weak tea' colour with a pH of 6·4-6·6, DH 1. The water temperature
was 72-74°F. A handful of peat fibre was placed in at one end of the tank
which the pair spawned in. A report by Ian Sainthouse in newsletter No.173,
January 1980 gave the following information - The fish prefer to be
in a quiet tank where they cannot see other fish in a neighbouring tank.
Fish can be maintained at DH 6-8 but few eggs are laid. Spawning was
induced by changing 30% of the water with cooler rainwater. Within 24
hours 10-15 eggs are usually collected. This number usually being layed
for 2-3 days. After a week this number dropped to almost zero. Tony Pinto in BKA Newsletter No.325, October
1992 reported having better success raising young with the parents in
a planted tank. Fry raised seperately did not fare so well & losses
ocurred after 3 weeks. George Mamonov in BKA newsletter No.438, March
2002 reported breeding them at DH 8. He found more males were produced
in this water. He used thawed ice with a pH of 6·5 - 6·8,
DH 0·5 - 2, water temperature 24-25°C. Eggs were deposited
on plants at the rate of 5 per week. Eggs laid on the base of the tank
went fungussed. Adults did not eat eggs but would eat the fry. Eggs
are sensitive to pollution. They take 12-14 days to hatch, fry being
1·5 - 2 mm on hatching. Fry are small & need infusoria &
rotifers followed by newly hatched brine shrimp. Growth rate of fry
is slow with maturity at 4-6+ months. | ||||||||||||||||||||||||||||
Diameter of Egg | 1.3 - 1.4mm | ||||||||||||||||||||||||||||
Remarks |
This sp. seems to dislike fresh new water. Water changes should be gradual & with well aged water (rainwater would appear to be best with at least one third mixed with aged tap water). This is not surprising though given that they inhabit more stagnant areas of the rainforest. |