Chaetopterid Polychaetes from Okinawa Island, Japan, with Notes on the Feeding Behaviour of Spiochaetopterus costarum costarum

Occurrence of four chaetopterid polychaetes, namely Phyllochaetopterus herdmani Willey, P. verrilli Treadwell, Mesochaetopterus sagittarius (Claparede), and Spiochaetopterus costarum costarum (Claparede), are reported from the sandy bottom of Sesoko Island, Okinawa, Japan. Setal morphology and several body characters are described based on the scanning electron microscopical observations. Among them, Phyllochaetopterus herdmani, P. verrilli and S. costarum costarum are new to Japan. Feeding behavior of S. costarum costarum was studied during the rearing experiments using glass tubes. This species performs mucous-bag feeding by employing foliaceous notopodia and a cupule located at the first setiger of middle body region