. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. CILIARY CURRENTS OF ADULA FALCATA 33 Particles which are accepted by the palps are carried orally over the crests of the palp folds and on to the mouth via the proximal oral groove (Fig. 4). Generally, rejected particles are passed direrctly to the ventral borders of the palps where they are collected by cilia lining the inner surface of the mantle lobes or the visceral mass (Figs. 2, 4, and 5). Subsequently, this rejected material is carried posteriorly to the embayment of the inhalant siphon (Fig. 6), and extruded from the
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. CILIARY CURRENTS OF ADULA FALCATA 33 Particles which are accepted by the palps are carried orally over the crests of the palp folds and on to the mouth via the proximal oral groove (Fig. 4). Generally, rejected particles are passed direrctly to the ventral borders of the palps where they are collected by cilia lining the inner surface of the mantle lobes or the visceral mass (Figs. 2, 4, and 5). Subsequently, this rejected material is carried posteriorly to the embayment of the inhalant siphon (Fig. 6), and extruded from the burrow as pseudofaeces. On occasion, A. falcata draws the palps across the lips of its mouth in a wiping fashion, leaving particle-laden mucus- strings within the proximal oral groove (Fig. 4). This material is ingested by the mouth and conveyed to the stomach, where it undergoes further sorting and FIGURE 6. The ventral aspect of the posterior portion of the mantle cavity in A. falcata. The valves have been expanded to demonstrate the ciliary currents (solid arrows) of the ctenidia and the inhalant siphon. The dashed arrows indicate the direction of the currents on the inside surface of the mantle-siphon lobes. The primary function of the labial palps of A. falcata is that of a sorting mechanism, but of almost equal importance is their role as a metering device, controlling the maximum volume of particles and mucus strings reaching the mouth. When the volume of food matter in the oral groove exceeds the ingestion rate of the mouth, mucus strings back up within the groove and are swept away by the rejectory cilia on the palp borders (Fig. 4). This rejected material either leaves the mantle cavity as pseudofaeces or, more rarely, is accepted by the cilia at the base of the inhalant siphon and returned to the ctenidia for resorting (Fig. 6). The ciliary currents of digestion The gut, associated organs, and ciliary currents of A. falcata are similar to those of
Size: 2296px × 1089px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
