Anatomical Structure of Ctenidium in Megangulus venulosa (Tellinidae: Veneroida: Bivalvia)

サラガイの鰓構造

Anatomical Structure of Ctenidium in Megangulus venulosa (Tellinidae: Veneroida: Bivalvia)

Creators Yamamoto Ken-ichi

Creators Araki Akira

Creators Handa Takeshi

The structure of the ctenidium in the Megangulus venulosa (Tellinidae: Veneroida) was examined. In the outer ctenidium, the outer lamina is lacking and the inner lamina is upturned from the ctenidial axis. In the inner ctenidium, the outer lamina is descending and the inner lamina is ascending. The ventral bend is situated along the top of the outer lamina. Only the inner ctenidium reaches the lateral oral groove into the labial palp. The laminae are flat and are composed of the ordinary filaments. The inner lamina of outer ctenidium is fixed in the fixed-membrane of the inner lamina of outer ctenidium which develops between the ordinary filament (OF) and the longitudinal vessel running along the edge of fixed-membrane of the inner lamina of outer ctenidium. The inner ctenidium is fixed in the inner-laminar connecting membrane which develops between OF of the inner lamina and OF of the outer lamina. Each OF is bonded together in the interfilamentar junction of the form of an intra-plical band and being fixed in the inner-filament connecting membrane composed of the lacunar tissue of the interfilamentar junction. Judging from these structure, the ctenidium of the M. venulosa is Homorhabdic eulamelibranch.

[ISSN]0370-9361