Early ontogeny of Labeotropheus Ahl, 1927 (Mbuna, Cichlidae, Lake Malawi), with a discussion on advanced protective styles in fish reproduction and development

Par Balon, Eugene K

Environmental Biology of Fishes, 2(2):147-176 août-1977. DOI: 10.1007/BF00005370


" With yolk as a food source, development of Labeotropheus takes place in the buccal pouch of the female until such time as juveniles are formed. Hatching from the vitelline membrane occurs early, after 6 days of incubation, and the eleutheroembryo develops without metamorphic stages directly into a juvenile, forming advanced structures like fins, skeleton and pigments, at a time when a large yolksac is still present. A strong circulatory network on the yolk and anal fin fold, and a yellow carotenoid pigment provide the oxygen supply within the closely packed buccal pouch. A relatively large self-sufficient juvenile, 14% of the adult fish size, is released from the mother's mouth 31 days after fertilization. The evolution of advanced hiding styles in reproductive guilds of fishes is discussed and ends with a speculation that the Latimeria, having had more geological time to refine its hiding style, releases fully developed young, 25 to 30% the size of the adult fish. The advanced style of hiding eggs is accompanied not only with fewer, larger eggs, but also by a successive increase in yolk density in terms of nutrients and respiratory pigments; these in effect determine the size of the released juvenile "

Classement: Physiologie et maladies, Lac Malawi.

Langue: English

Balon, Eugene K. 1977. "Early ontogeny of Labeotropheus Ahl, 1927 (Mbuna, Cichlidae, Lake Malawi), with a discussion on advanced protective styles in fish reproduction and development". Environmental Biology of Fishes. 2(2):147-176. DOI: 10.1007/BF00005370 (crc02950) (résumé)