PARTICLE FEEDING IN NATURAL POPULATIONS OF THREE MARINE DEMOSPONGES

作者：Henry M. Reiswig · 发表于：Biological Bulletin · 年份：1971 · DOI：10.2307/1540270 · 被引用次数：490 · 研究领域：Marine Biology and Environmental Chemistry、Marine Toxins and Detection Methods、Microplastics and Plastic Pollution

1. Microscopic and chemical analysis of ambient and exhalant water samples collected in situ indicates that the net POC diet of three tropical Demospongiae, Mycale sp., Verongia gigantea and Tethya crypta, consists primarily (80.5%) of particulate (filterable) organic matter which is unresolvable by direct microscopy (URPOC). Microscopically resolvable particulate material (MPOC) accounts for only the remaining 19.5% of the POC diet of these sponges. 2. The three sponges retain available resolvable particulate material within the size range of 0.3-50 µ at high efficiencies—means are 79.0% by calculated carbon content and 82.0% by particle volume. 3. Major components of the MPOC diet and of the total POC diet of these sponges are respectively: unarmored cells 83%, 16.2%; armored cells 12.3%, 2.4%; and bacteria 4.6%, 0.9%. 4. Two functionally independent capture systems appear to be operative in all 3 species, accounting for a basic bimodal pattern of particle retention. A system involving particles between 5 and 50 µ is attributable to phagocytosis by cells lining the inhalant system. A second system involving particles of the bacterial size range (0.3-1 µ) involves capture at the choanocyte collar and ingestion by choanocytes. 5. The amoebocyte capture system is by necessity constantly functional and must accept all particles entering the ostia. A transport path by amoebocyte migration cycles is proposed to account for transport and release of intact armored plankton at signi...