Definition: The word 'actinopterygian' refers to a type of fish that belongs to the family Acanthopoda, which includes many species found in both freshwater and marine environments. These fish are primarily adapted for living in cold water and have evolved to live in large groups known as schooling. Actinopterygians are generally referred to as 'fish' because they have a single nucleus surrounded by a cytoplasm that is similar to the nucleus of some animals but much smaller. They also have a relatively short life span, often living for several months or even years. Actinopterygian fish can be found in many different aquatic habitats, including coastal and freshwater waters where they are known to live in schools with other species. Some examples include the common carp, brown trout, pike, and perch. Actinopterygians have a number of interesting characteristics that set them apart from other fish. They have large eyes for vision and tend to feed on aquatic plants and plankton.

actinopterygian