This research note aims at reporting the existence of adult Capitella
capitata sp. I (Annelida: polychaeta) featuring two functional tails.
Seven individuals of this kind have been isolated during 1987 from a m
onospecific laboratory culture held at the Chesapeake Biological Labor
atory (University of Maryland, USA) and originating from worms collect
ed in the vicinity of Woods Hole (Massachussetts, USA).