. The biology of marine animals. Marine animals; Physiology, Comparative. 208 THE BIOLOGY OF MARINE ANIMALS and thence to the buccal funnel. MacGinitie has also described an altern- ative mode of feeding by formation of a mucus-bag. This is produced by the aliform notopodia and extends posteriorly to a dorsal cup organ where it is rolled up. All the water which flows through the burrow must traverse this net, which filters out suspended food matter. At intervals the front margin is detached and the net is transported anteriorly to the mouth by. Fig. Mucus-bag Feeding in a Tubicolous Polyc
. The biology of marine animals. Marine animals; Physiology, Comparative. 208 THE BIOLOGY OF MARINE ANIMALS and thence to the buccal funnel. MacGinitie has also described an altern- ative mode of feeding by formation of a mucus-bag. This is produced by the aliform notopodia and extends posteriorly to a dorsal cup organ where it is rolled up. All the water which flows through the burrow must traverse this net, which filters out suspended food matter. At intervals the front margin is detached and the net is transported anteriorly to the mouth by. Fig. Mucus-bag Feeding in a Tubicolous Polychaete Chaetopterus variopedatus. (From MacGinitie, 1939.) /~vXâ>J^ .JV â â â J\/~%fyu«^J|ft~»4r»^^ Fig. Extract from an Irrigation Record of Chaetopterus variopedatus (duration 4 hours) The worm was carrying out mucus-bag feeding and pumping steadily, except for brief pauses at the peaks when the lever returns to null position. The frequency is about 1 fan stroke per sec, too fast for individual strokes to be distinguished on this record. At the pauses, which occur every 18 min, a mucus-bag is passed forwards to the mouth and swallowed. (From Wells and Dales (103).) reversal of ciliary beat in the dorsal groove. The mucus-bag forms a very efficient straining apparatus, and by feeding proteins of different particle sizes it has been calculated that the mesh openings are about 40 A in diameter (63, 65, 103). In cryptocephalous polychaetes exemplified by Sabella, feeding is carried out by a branchial crown consisting of a circlet of tentacles (Figs. ,). These bear lateral pinnules which are ciliated and form a filtering apparatus. Water is drawn into the branchial funnel by abfrontal cilia on. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Nicol, J. A. Colin (Joseph Arthur Colin), 1
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