Biology of Finfish and Shellfish (2+1)

4.6.7. Internal Bearers

In these fishes, the fertilization takes place internally. Incubation may take place either internally or externally (to breed or sit on eggs for hatching). There are 3 major categories. Internal carriers / bearers produce small number of eggs.

1. Ovi-ovoviviparous : Fertilization is internal, incubation is external. No nourishment from the parents. e.g.: sharks and skates
2. Ovoviviparous: Fertilization internal, incubation is also internal without any nutrient supply from the females, but they get protection (Hatchlings come out from the body of female). e.g.: many sharks and skates and living fossil fish, Latimeria chalumnae.
3. Viviparous: Fertilization internal, incubation is internal; also they get nutrient supply from females. e.g.: some sharks – carcharinidae and poeciliidae.