Livebearing fish Live-bearers are some of the most common fish to have in a home aquarium. Some popular live-bearers include but are not limited to guppies, mollies and platys.
Live bearers are fish that are born almost fully developed, and are called fry when first born.
Some fish lay eggs that are fertilized by the male, and the live-bearers actually copulate. They are routinely sold at pet stores and they are usually tank-bred fish. Thus explains some of the unique colors and strains that you see in the pet stores. Fish caught in the wild are rarely seen in pet stores in part because the countries where live-bearers are found are not involved in exporting fish. A unique feature of live-bearers is that many are sexually dimorphic.