Description
U.S. Government Printing Office, Washington, Published 1958. Wraps (staple bound), ii, 73-82 pp.; 26 cm. Fishery Bulletin No. 129, extracted from Fishery Bulletin of the Fish and Wildlife Service, Volume 58.
Rare, out-of-print & unusual books · Since 1997
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Condition & notes
In acceptable condition. Grey paper covers with mild shelf wear, a few small nicks and light creasing to edges, and some toning along edges. Previous owner's address stamp and date-received stamp on front cover. Binding tight. Damp-staining to top corners of pages; pages show mild toning but are otherwise unmarked.A scientific paper by Theodore R. Rice and Rebecca J. Smith reporting experimental work on filter-feeding physiology in the hard clam (Venus mercenaria, now Mercenaria mercenaria) using radioactively labeled phytoplankton. An early example of radioisotope tracer methodology applied to shellfish ecology.[From the abstract] Filtering rates of the hard clam, Venus mercenaria L., were determined by ascertaining the number of radioactive phytoplankton removed from water pumped through the filtering mechanism of the clam. If the cells are not completely filtered from the water pumped, the filtering rate of the clam is less than the pumping rate. The term "filtering rate" refers to the volume of water from which the cells are removed per unit of time. The labeling of algae with radioactive phosphorus made it possible to follow smaller initial populations than have been used in most previous investigations, yet it provided a means of accurately measuring slight changes in these populations. The number of cells present at the beginning of an experiment and the size of these cells influenced the filtering rate. The filtering rate in unialgal suspensions was different from that in mixed suspensions. The filtering rate in natural populations of phytoplankton was higher than in unialgal suspensions of green algae and lower than in unialgal suspensions of diatoms. Silt had an adverse effect on the hard clam, since it reduced the filtering rate and stimulated the formation of pseudofeces. A similar effect was produced by the presence of Chlorella in the water. In relating filtering rates to size of clams, more water per gram of meat was filtered by small clams than by large clams.