Branchiostoma

Branchiostoma is one of the few living genera of lancelets (order Amphioxiformes). It is the type genus of family Branchiostomatidae.

thumb|left|Anatomical diagram of B. lanceolatum (click for description) These small vaguely eel- or snake-like animals are close relatives of vertebrates. The scientific name means "gill-mouth", referring to their anatomy – unlike vertebrates, they do not have a true head (with a skull capsule, eyes, nose, a well-developed brain etc.), but merely a mouth adjacent to the gill-slits, with the slightly enlarged anterior end of the dorsal nerve cord above and in front of them. It dislikes the light.