In this method, the laid eggs are collected to the brooder’s mouth(the female carries the first incubation period after laying), fertilized and develop to fry. Eggs development relies on oxidized water flow through the brooder’s gills. There are two classifications of mouth-brooding among cichlids in Lake Tanganyika:
A) Maternal mouth-brooding– the female incubates the eggs, with no help from the male. For example – the cichlid Cyprichromis leptosoma (Boulenger, 1898). Spawning occurs at the male’s territory in mid-water. After spawning, the female leaves the area and joins a group of mouth-brooding females for protection. After three weeks of incubation, the females release the fry together in a common area
The spawning of the cichlid Callochromis macrops (Boulenger, 1898) takes place at the male’s pit, located near rocks or vegetation. After spawning, the female leaves the pit and hides among the rocks or heavy vegetation, there the female will stay for the next three weeks and the realese the fry in the same area. In both cichlids that were mentioned, there’s no guarding the fry further more after completing incubation.
Callochromis macrops Ndole spawn
B) Bi-parental mouth-brooding– the male and female incubate the clutch, each in it’s turn. The female will incubate the clutch first, and after few hours\days (differs in each genus) will transfer the clutch to the male. This action is repeated several times during the incubation period and the pair exchange the maintenance of the clutch many times. For example – male and a female of the cichlid Eretmodus cyanostictus (Boulenger, 1898) lives in pairs at the shallow rocky area. After spawning, the female remains near the territory of the male and hids from him. After several days of incubation, the female leaves her hideout and signals the male, then they exchange incubation on the clutch and so on until full development of the fry, and then the offsprings released at the rocky area. In bi-parental mouth-brooders, female can eat after several days of fasting, unlike maternal mouth-brooding, where the female does not eat\barely eat for three weeks of incubation. Therefore, recovery and readiness for next spawn would be faster in bi-parental females.