[Ebook] Encyclopedia of Aquarium & Pond Fish – Introduction to Freshwater Fish – Breeding – Reproductive behavior
Fish can be divided into two broad categories on the basis of their breeding behavior. Egg-layers, which form the majority, practice external fertilization, while in livebearers the eggs are fertilized in the female’s body and emerge as fully formed young. Some species show little regard for their offspring and cannibalize their own eggs or fry. Others display surprisingly high levels of parental care.