Aphyosemion ogoense (PELLEGRIN, 1930)

Broken-line Killifish

Classification

Order: Cyprinodontiformes Family: Nothobranchiidae

Distribution

Described from the M’Passa River in the upper Ogooué drainage basin, southeastern Gabon. Its current known range extends from that region into northern and central Republic of the Congo.

Habitat

It’s usually found in small streams under forest cover.

Maximum Standard Length

45 – 50 mm.

Aquarium SizeTop ↑

A tank or container with base measurements upwards of 45 ∗ 25 cm is acceptable for a pair or trio.

Maintenance

The aquarium should ideally should have dense areas of planting and other décor to serve as cover, and the use of floating plants to diffuse the light is recommended. The species is an accomplished jumper so the cover must be very tight fitting.

Water Conditions

Temperature: 18 – 22 °C

pH: 5.0 – 6.5

Hardness: 0 – 143 ppm

Diet

Small live or frozen foods such as Daphnia or bloodworm are preferred although the fish will often accept good quality flake.

Behaviour and CompatibilityTop ↑

A. ogoense can be kept in a community set-up provided tankmates are chosen with care. Any species chosen must not be so vigorous as to outcompete the killis and must also be comfortable in the slightly cooler temperatures required. It’s best kept in a species tank.

Sexual Dimorphism

Males are much more colourful than females and have longer dorsal, caudal and anal fins.

Reproduction

There exist several different methods of spawning it, and much is down to personal preference. A pair can be spawned in an aquarium with a base as small as small as 30 cm x 20 cm. It’s often recommended that this species be spawned in trios but brood sizes tend to be lower when it is bred this way, perhaps due to the fish that is not spawning eating some of the eggs.

Many breeders do not use filtration in killi breeding setups but the use of a small, air-driven sponge filter to prevent stagnation is not a bad idea. Water should be slightly acidic (pH 6.0-6.5) with quite a cool temperature (64-68°F) and the tank should be unlit. Peat filtration is also beneficial.

The fish should be conditioned on a varied diet of live and frozen foods. We recommend keeping the 2 sexes apart in separate conditioning tanks and selecting the best male and plumpest female before placing them in the spawning tank. This method allows females to recover between spawnings. A. ogoense will deposit eggs either in the substrate or in clumps of vegetation in nature and thus, the spawning medium can either be a layer of peat moss on the floor of the aquarium, clumps of fine-leaved plants such as java moss or spawning mops. We recommend a bare-bottomed setup with spawning mops for both ease of maintenance and egg collection.

The eggs can be left in the aquarium to hatch with the parents but some eggs and fry may be eaten. If you want to raise a good-sized group, the eggs should be removed. 10-20 eggs are deposited daily for around 2 weeks and these should be removed gently as they are noticed. Each pair should only be allowed to spawn for a week or so before being returned to the conditioning tank, as the spawning process is hard on the fish (particularly the female) and they can become fatigued and weak if left for too long.

Once removed, the eggs can be incubated either in water or by placing them on a damp layer of peat moss in a small container (margarine tubs are ideal). Less eggs tend to fungus using the latter method, although fungussed eggs should still be removed as they’re spotted. This prevents the indfection from spreading.

If incubating in water, the eggs can be transferred to a small aquarium containing water from the spawning tank to a depth of 1-2 inches to which has been added 1-3 drops of methylene blue, depending on volume. This container should be kept under darkness (the eggs are very sensitive to light) and checked daily for fungussed eggs, which should be removed with a pipette. The eggs will hatch in around 12-21 days depending on temperature.

If incubating on peat moss, place the container in a warm, dark place and simply leave it for 18 days, after which the eggs will be ready to hatch. If you’re spawning several species or multiple broods, it’s a good idea to label each container with the date, hatching date, species and number of eggs to prevent any disasters. Hatching can usually be induced by simply placing the eggs in the raising aquarium after 18 days, where the wetting of the eggs stimulates hatching. If this fails, blowing gently into the water through a straw or piece of airline can trigger hatching.

The fry are large enough to accept Artemia nauplii or similar immediately once free-swimming with the introduction of larger and frozen varieties after 2 weeks or so. The water must initially be kept very shallow but the level can be raised as the fry grow.

Extreme care must be taken regarding water quality in the raising tank as the fry are very susceptible to velvet disease. The fry should be fed twice a day with small water changes every 2-3 days for the best growth.

NotesTop ↑

This species is not an annual fish, being found in permanent bodies of water in nature. Over 20 different forms of it have been discovered at different localities and a handful have been given subspecific names. The most popular in the aquarium hobby include A. o. ottogartneri and A. o. pyrophore, both of which were initially described as separate species. Obviously, the different forms must never be kept together in aquaria as they may hybridise.