Redescription of Scoliorhapis lindbergi comb. nov. (Echinodermata: Holothuroidea: Apodida: Chiridotidae), with Special Reference to the Ultrastructure of Sigmoid Bodies

Abstract

We reclassify and redescribe the apodid holothurian Scoliodotella uchidai Oguro, 1961 as Scoliorhapis lindbergi (D’yakonov in D’yakonov et al., 1958) comb. nov., based on newly collected topotypes of the former from Akkeshi Bay, Ja- pan. We confirm the previously proposed, but not widely recognized, synonymy between these two nominal species. Scan- ning electron microscopy of 968 sigmoid bodies from 17 specimens of S. lindbergi from Akkeshi Bay revealed that 12.0% of them possessed spinelets, which varied in size, number, and arrangement, and that 0.8% were anchor-shaped, resembling ossicles characteristic of Synaptidae.