. Culture methods for invertebrate animals;. Invertebrates -- Cultures and culture media; Invertebrates -- Collection and preservation. Fig. 8.—The clam hoe. Fig. 9.—The hooker. (Fig. 9) used in digging in the hard mud, has four thin, sharp prongs and a short handle. The shovel. An ordinary steel shovel is a valuable tool for collecting animals living in sand or mud on the beaches or in shallow water. The dredge. The dredge is the most efficient instrument for collecting bottom dwelling forms regardless of the depth of the water. Dredging at great depths is a difficult operation requiring cost
. Culture methods for invertebrate animals;. Invertebrates -- Cultures and culture media; Invertebrates -- Collection and preservation. Fig. 8.—The clam hoe. Fig. 9.—The hooker. (Fig. 9) used in digging in the hard mud, has four thin, sharp prongs and a short handle. The shovel. An ordinary steel shovel is a valuable tool for collecting animals living in sand or mud on the beaches or in shallow water. The dredge. The dredge is the most efficient instrument for collecting bottom dwelling forms regardless of the depth of the water. Dredging at great depths is a difficult operation requiring costly equipment, but dredging in shallow water not exceeding 100 feet, may be carried out from a small boat and does not require special machinery. There are many types and sizes of dredges, ranging from small instruments about 1 foot wide to large commercial oyster dredges several feet wide and having a capacity of over 25 bushels. The description given here refers only to small in- struments that may easily be used by the collector of scientific material. The dredge is always made of a rigid iron frame to which a bag made of heavy netting or interwoven chain rings is attached. The most com- monly used type is the so-called scraper or scallop dredge (Fig. 10) which consists of a triangular framework with an iron blade (B), 2 inches wide, set at an angle so as to dig into the bottom. On the upper side a raised cross bar connects the two arms. The net with a wooden hori- zontal bar at the end is fastened to the cross bar and to the top of the blade. Additional weight (A) may be put on the cross bar if it is desired that the instrument cut deeper into the bottom. The dredge shown in figure 10 has a metal sheet (A) which serves the double purpose of pro-. 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 Galtsof
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Keywords: ., bookcentury1900, bookcollectionameri, bookcollectionbiodiversity
