How do cypricichlids from Lake Tanganyika, such as Cyprichromis species, breed in the wild? Matt Clarke explains.
These beautiful spindle-shaped cichlids from Lake Tanganyika are unusual among cichlids because they live and spawn within the water column and don’t use the substrate for spawning.
Adults are found mainly at depths of 4-20m/13-66’ and form large schools which feed on zooplankton, such as Daphnia. The schools are often assorted by size and non-breeding fish often swim in open water elsewhere.
Like marine anthias or fairy basslets, Cyprichromis occupy a midwater three-dimensional territory which they defend on all sides from rival males. Large schools of females form a huge sedentary school with which the males periodically spawn.
Females visit male mating territories, spin in the water column, release an egg which the male fertilises and then catches it in her mouth. She then nuzzles the male’s abdomen to persuade him to ejaculate near her mouth so she can draw in the milt and fertilise the eggs. Once she has laid her clutch of just nine or ten, she leaves the territory and rejoins the shoal of females for protection.
In the lake, the spawning cycle of Cyprichromis follows the lunar cycle. The fry released by are very large — about 15-20mm/0.6-0.8” long — and capable of taking zooplankton as soon as released from the female’s mouth.
Juvenile of Cyprichromis leptosoma form large schools near nesting sites of the fish-eating Lepidolamprologus profundicola. The female profundicola drive away fish that might eat their own eggs, but don’t bother with the relatively harmless C. leptosoma. Cyprichromis use L. profundicola’s breeding territory as a zone safe from potential predators.
This item was first published in the November 2009 issue of Practical Fishkeeping magazine. It may not be reproduced without written permission.