ABSTRACT
Suckered tube foot is absent from asteroids belonging a few families, while they have pointed tube feet. Presence and absence of suckered tube feet has been an important character in sea star taxonomy (Blake 1987). Because of bearing characters, one of which is pointed tube feet, Blake (1988) considered paxillosidans including the genus Astropecten, which commonly has been considered primitive, is specialized. Suckered tube feet were reported by external observation in the metamorphosing juveniles of Astropecten latespinosus (Komatsu 1975) and Astropecten scoparius (Oguro et al. 1976), which the tube feet of their adult lack suckers. In the present study, scanning electron microscopic observations of tube foot of just metamorphosed juveniles and adult in Astropecten polyacanthus Müller et Troschel in addition to some histological structure by 1 µm thick sectioned specimens are presented.
