Internal Fertilization Examples

Difference between External Fertilization and Internal Fertilization

Some examples of organisms that undergo internal fertilization are:

Internal Fertilization Fish

When a fish undergoes internal fertilisation, the male inserts sperm into the female’s vaginal entrance via an intermittent organ. Only 500 of the more than 33,000 species of bony fish and basal cartilaginous fish exhibit this mechanism, making fish comparatively rare in general.

Internal Fertilization Mammals

All mammals like humans, dogs, elephants, and whales use internal fertilization. The mammalian reproduction involves the direct deposit of sperm into the female reproductive system during copulation and the fertilization occurs within the uterus or oviducts.

Internal Fertilization Reptiles

Reptiles like lizards, turtles, and snakes use internal fertilization, where the males of these species have hemipenis or a penis that transfers teh sperm into the female reproductive tract.

Internal Fertilization Amphibians

Most amphibians rely on external fertilization some of them like salamanders and caecilians use internal fertilization. The salamanders use spermatophores which are picked up by the females in the cloacal region to fertilize the eggs internally.

Internal Fertilization Birds

Most of the birds engage in internal fertilization but the method differs from mammals as the birds lack external genitalia. The birds perform a “cloacal kiss” where the male and female cloacal touch and allow the transfer of sperm.