A New Asymmetrical Near-bottom Calanoid Copepod, Paramisophria platysoma, with Observations of Its Integumental Organs, Behavior and In-situ Feeding Habit

非対称の体を持つ近底層カラヌス目カイアシ類の1新種Paramisophria platysomaの記載及びその皮殻器官, 行動, 天然餌料

Ohtsuka Susumu

Mitsuzumi Chikanobu

日本プランクトン学会報

A new hyperbenthic calanoid copepod, Paramisophria platysoma collected from the littoral and sublittoral zones on the Pacific coast of Japan is described. The new species has a remarkably asymmetrical body with the left lateral side compressed. However, a SEM examination revealed that the integumental organs of the female cephalothorax are nearly symmetrically distributed. Three different patterns of behavior of living copepods were observed using a VHS tape recorder sytem: (1) usual, continuous swimming with the compressed left lateral side parallel to the bottom, using antennae 2, mandibular palps and maxillae 1; (2) fast "jumping" possibly with flaps of swimming legs; and (3) resting with the left lateral side just on the bottom. The gut content analysis of adult females showed that they fed carnivorously on benthic harpacticoid nauplii and copepodids. Their asymmetrical bodies, peculiar swimming behavior and feeding habit dependent on benthic organisms seem to be adaptations to a hyperbenthic life in shallow waters.

Zoology [ 480 ]

eng

日本プランクトン学会

Copyright (c) 1990 The Plankton Society of Japan

[ISSN] 0387-8961

[NCID] AN00197015