Anguilliformes (2026 Release)

: 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 anguilliformes

: 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 : Many species lack scales entirely; if present,

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. Key Biological Features : The family Anguillidae includes

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

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.