While many other fish—such as electric eels and swamp eels—have evolved similar elongated shapes, they belong to different taxonomic orders and are not "true" eels.
True eels are found globally in a vast range of aquatic environments: anguilliformes
: True eels are distinguished by the fusion of rostral bones into a single complex and the lack of a pelvic girdle. While many other fish—such as electric eels and
Anguilliformes is the taxonomic order of , a group of ray-finned fishes containing approximately 1,000 species across 20 families. They are defined by their elongated, cylindrical bodies and a unique life cycle involving a transparent, leaf-like larval stage called a leptocephalus . Key Biological Features They are defined by their elongated, cylindrical bodies
: The family Anguillidae includes catadromous species that live in freshwater but migrate to the ocean to spawn. Major Groups : Well-known families include: Muraenidae : Moray eels. Congridae : Conger and garden eels. Anguillidae : Freshwater eels. Ophichthidae : Snake and worm eels. Life Cycle
: Most species have a snakelike appearance with a complete absence of pelvic fins . Their dorsal, anal, and caudal fins are often continuous, forming a single fringe around the tail.