Species of this genus inhabit most areas of Africa east of Benin (formerly Dahomey), and particularly from the Niger to the Congo. Seasonal species are less common than the continuous breeders of drought-free areas; some species exhibit breeding patterns intermediate between both types.
The eggs of the blue gularis, a seasonal killifish, incubate in 5 weeks at 22°C. Size: 12 cm. •
The exact coloration of the steel-blue killie varies according to its geographical origin. It is a continuous breeder. The eggs hatch in 2-3 weeks. Size: 6 cm.
The two-striped aphyosemion reaches 6 cm in length, but its growth is slow. The sticky eggs incubate in less than 2 weeks. It is a continuous breeder. Size: 6 cm.
Walker's aphyosemion or Walker's killifish is a seasonal breeder. Kept in continually moist peat at 18-20°C, the eggs hatch in under 15 days. Size: 6 cm.
The marbled killifish employs an intermediate form of reproduction. If you leave the eggs in the aquarium, incubation lasts 15-20 days, and hatching will be correspondingly staggered Kept in peat, they will take longer to hatch, but all the fry will emerge simultaneously. Size: 6 cm. T
The Cape Lopez lyretail or the lyretail panchax is obtainable from most commercial outlets and is the species of aphyosemion most frequently recommended to hobbyists wishing to familiarize themselves with the genus. It is hardy, and spawns continuously without particular problems. Prepare a bed of peat in a small tank, introduce fine-leafed plants and keep the temperature below 23°C.
The pH should be between 6 and 7, with almost zero hardness. The female lays 50-100 eggs, each only 1 mm in size, which hatch after 2 weeks. Remove any infertile eggs (cloudy instead of transparent). Hatching can be accelerated by raising the level of dissolved CO2 (carbon dioxide) - a technique also valid for other species. One way to do this is by blowing gently down a tube into the water. Size: 6 cm.
Other Cyprinodontidae: Roloffia - Epiplatys - Aplocheilus - Fundulus - Rivulus — Nothobranchius - Cynolebias
Besides Aphyosemion, there are several other genera popular with hobbyists. They are not normally available from commercial outlets, but you can obtain them through clubs and aquarists' associations. Roloffia species are native to the African coastal countries west of Benin, unlike their close relatives Aphyosemion. They prefer soft water (23-24°C maximum) and moderate levels of light. Epiplatys is a genus of killifish found from Senegal to Chad and even as far south as the Congo, in the watercourses of tropical forests. They are continuous breeders, usually sticking their eggs to plants. The genus Aplocheilus consists of a small number of species native to Asia. Their breeding habits resemble those of Aphyosemion.
Fundulus is a genus originating from the United States - some species are found in Canada - and Central America. Specimens are rarely found on the commercial market. The eggs adhere to plants, hatching in around 2 weeks.
Rivulus, from Central America or the northern zones of South America, is a genus preferring calm waters, with a moderately warm temperature of around 24°C. Note that these fish can jump out of the aquarium. They are continuous breeding, laying eggs on plants or on the bottom.
Nothobranchius species live in the waters of East and South-East Africa, in those areas with alternating rains and droughts. Fish of this genus have more slender bodies than those belonging to Rivulus, but are just as colorful.
Cynolebias comprises seasonal killies from South America. Some species will even bury themselves in the peat to lay their eggs. There are several species, closely related to the two illustrated below.
The black-finned pearl fish is a seasonal species; the eggs must be kept in peat for 4 months. Size: 5 cm.
The males of the Argentinian pearl fish will sometimes fight one another or harry the females. The breeding of this seasonal species is difficult. The eggs must be kept for 3-6 months in moist peat; after replacement in water, they hatch within a week. Size: 5-6 cm.
• Rivulus cylindraceus
The female of the Cuban rivulus is arger than the male and can also be distinguished by the black patch bordered with white on her caudal fin. The eggs (3 mm) incubate in around 15 days. There are no particular requirements for water quality. Size: 7-8 cm.
• Notobranchius guentheri
A seasonal, difficult breeder, Gunther's notho is small but very handsome. You need to preserve the eggs in peat for 6-12 weeks; return them to water, and they will hatch over a period of
The striped panchax requires a large tank, as it can reach 10 cm in length, with plenty of vegetation. The eggs are laid in the plants; the fry are tiny, and they require live prey small enough to swallow. Size: 8-10 cm.
The clown killie is only 3-4 cm long and is a top-dweller. It lays its eggs in fine-leafed vegetation; they hatch after 8-10 days.
A CYPRINODONT TO KEEP WITH CICHLIDS:
This is a species of interest to anyone seeking tankmates for Cichlids (see page 104). Both originate from the same habitat: Lake Tanganyika. L. tanganicanus, the Tanganyika pearl killie can reach 12 cm and its lively, shoal-swimming behavior makes it an ideal companion for Cichlids, though a fascinating subject in itself. Unfortunately, you are unlikely to obtain this species from your dealer.
• Roloffia occidental's
The golden pheasant is a seasonal species spawning in soft, acidic conditions. The diapause can last 4-5 months, sometimes longer. The male is brightly colored, the female duller. Size: 8-9 cm.
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