Fundulus gardneri Boulenger, 1911; Haplochilus brucii Boulenger, 1911; Aphyosemion gardneri (Boulenger, 1911); Aphyosemion nigerianum (Clausen, 1963); Aphyosemion gardneri vanderveldei Radda, 1974; Aphyosemion gardneri lacustre Langton (ex Radda), 1974; Aphyosemion gardneri mamfense Radda, 1974; Aphyosemion gardneri obuduense Wright and Jeremy, 1974; Aphyosemion gardneri clauseni Scheel, 1975; Aphyosemion (Paraphysemion) biafranum Kottelat, 1976; Aphyosemion nigerianum meridionale Kottelat, 1976
gardneri: named for ‘Mr. R. D. Gard’ner’, who collected the type specimens.
Native to the Cross River system in southeastern Nigeria and western Cameroon plus the Benue River drainage in central Nigeria.
Known populations include Akaram, Akure, Enugu, Kluge, Lafia, Makurdi, Nsukka, Okwoga and Udi Mountain.
The type series consists of three specimens collected from ‘head-waters of Cross River, Calabar…Okwoga 7°N, 7°45′E’ which corresponds to the town Okwoga in Benue state, mideastern Nigeria.
Of the nominal subspecies (see ‘Notes’), F. g. lacustris is known only from Lake Ejagham and its tributary stream in western Cameroon, F. g. mamfensis occurs in rainforest tributaries of the upper Cross River in the Mamfe lowlands of southwestern Cameroon and F. g. nigerianus is distributed throughout southern, southwestern, central, northern and eastern Nigeria including the Niger and Benue rivers plus minor coastal drainages of southeastern Nigeria, and in the Benue system it’s also been recorded in western Cameroon.
Collections of wild fish are generally labelled with some form of code in order that they can be told apart, thus limiting the possibility of hybridisation.
Most forms inhabit creeks, swamps, streams and pools in humid, forested, highland savannah and areas of rainforest.
Some habitats periodically dry out but in many cases this is not a regular, annual event and they may retain water in some years.
Maximum Standard Length
50 – 55 mm.
The set-up need not be too complicated but be sure to cover the aquarium well since this species is a prodigious jumper.
Temperature: 20 – 26 °C
pH: 6.0 – 7.5
Hardness: 18 – 179 ppm
Behaviour and CompatibilityTop ↑
Males can be aggressive towards one another but provided the aquarium contains sufficient refuges a group can normally be maintained together.
Ideally stock 2-3 females per male in order that no individual is singled out for excessive attention from the male(s).
Males grow larger, are more brightly-coloured and develop more-extended fins than females.
The unpredictable nature of many of this species’ natural habitats have resulted in it evolving what’s often referred to as a ‘switch’ or ‘semi-annual’ breeding strategy whereby the eggs are able to withstand a period of drying but will also incubate and hatch when permanently submerged in water.
If conditions are suitable most forms are not difficult to breed with eggs deposited among live plants, aquatic mosses, synthetic mops, etc., while some breeders prefer to use a small tray of peat which is removed and dried post-spawning.
Eggs are best removed on a daily basis as the adults will eat any they find.
Under water they normally hatch within 14-21 days depending on temperature while 3-4 weeks tends to be the ‘standard’ period of drying.
The fry are free-swimming almost immediately and can be offered Artemia nauplii, microworm and similar as first foods.
This species is also known as ‘Gardner’s Killi’ and ‘blue lyretail’ and the commonly-available aquarium forms are perhaps among the best choices for those new to keeping killifishes being relatively hardy, colourful and easy to breed.
A number of ornamental strains have also been line-bred by aquarists including ‘gold’ and albino.
Wild populations exist in numerous colour forms of which three, F. g. lacustris, F. g. mamfensis and F. g. nigerianus, have been described as nominal subspecies.
The latter is among the commoner forms encountered in the aquarium trade.
- Boulenger, G. A., 1911 - Annals and Magazine of Natural History (Series 8) v. 8 (no. 44): 260-268
Descriptions of new African cyprinodont fishes.