TUBE-BUILDING AND FEEDING IN CHAETOPTERID POLYCHAETES

Abstract

1. Tube-building and feeding were investigated in members of the chaetopterid genera, Telepsavus, Phyllochaetopterus, Ranzanides and Mesochaetopterus.2. With the exception of Chaetopterus, all members of the family construct a more or less straight tube oriented vertically in the substratum. The tube contains one or several transverse perforated partitions.3. The tube is secreted by the ventral surface of the anterior body region. The enlarged fourth notopodial setae are used to remove partitions or to tear open the side of the tube wall in order to construct a new section of tube.4. In Telepsavus and Phyllochaetopterus water is driven through the tube by the beating of ciliary membranelles. The membranelles line the ring-like openings formed by the foliaceous notopodia of the middle body region. In Ranzanides, Mesochaetopterus, and Chaetopterus water is pumped through the tube by the piston-like action of segments of the middle body region.5. A mucous bag is utilized for feeding in all chaetopterids. The number of bags varies from one to many and they are always produced by the middle body region.6. Except in Chaetopterus, a pair of long palps arise from the dorsal side of the head. Each palp carries a large and a small ciliated groove. The large groove, in which cilia beat proximally, functions as an accessory feeding device. The more important smaller groove, in which cilia beat distally, provides for the ejection of fecal pellets and any undesirable material which enters the tube with the incoming water current.