Anguilliformes May 2026

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.

The most distinct feature of the Anguilliformes is their . After hatching as transparent leptocephali , they drift on ocean currents for months or years. They then transform into juvenile "glass eels" before reaching their adult form.

: 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. anguilliformes

: Many species lack scales entirely; if present, they are deeply embedded in the skin. Diversity and Habitat

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 While many other fish—such as electric eels and

: True eels are distinguished by the fusion of rostral bones into a single complex and the lack of a pelvic girdle.

: 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 They then transform into juvenile "glass eels" before

The oldest fossil record of a living true eel lineage ... - bioRxiv