Ctenidia


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Ctenidia

 

the primary gills of mollusks. Each ctenidium is a bipinnate projection in the mantle cavity; it consists of an axial plate or lamella from the flat sides of which project numerous filaments covered with ciliated epithelium. Along one narrow side of the plate there is a blood vessel that brings venous blood, and on the other side there is a blood vessel that carries away oxygenated arterial blood. The number of ctenidia ranges from many pairs (in Amphineura) to a single pair (in Gastropoda and Cephalopoda), and even a single ctenidium (in many Gastropoda). The lamellar gills of bivalve mollusks are a pair of modified ctenidia.

References in periodicals archive ?
Two long ctenidia extending length of succeeding sternite, palpus with no spine-like setae on ventral side.
Abdomen: two ctenidia extending length of succeeding sternite (Fig.
Our identification for this group is based on the length and shape of the male ctenidia as well as the shape of the male fixed finger, particularly the tip.
This study revealed five morphologically distinct endosymbionts of natural Pacific geoduck populations in the Pacific Northwest: an RLO in the ctenidia, an unidentified metazoan in the siphon epithelium, Steinhausia-like spp.
Rickettsiae in ctenidia epithelial cells of the hard clam, Mercenaria mercinaria.
It is the only member of this group without ctenidia.
Flagellum complex typical of group, no ctenidia, no palpal papillae.
The allotype but not the paratype with four tiny, thin ctenidia.
13]C relative to ctenidia and digestive gland tissues in all age classes (Table 1a).
Of the three tissues analyzed, ctenidia was the least variable in [delta][sup.
pansa is an antero-posteriorly elongated organ located at the internal surface area of the mantle, that folds on its posterior side near the rectum, right of the ctenidia and anterior to the kidney (Fig.
Endoscopic visualization of the functional morphology of the ctenidia of the unionid mussel Pyganodon cataracta.