Hurricanes, red tides, fresh water, and mechanical harvesting have been 

 blamed for disappearance of clam stocks in the Ten Thousand Islands area, 

 but the cause has not been identified. Densest concentrations of hard clam 

 on the west coast of Fla. are found on firm, sticky mud bottoms with 

 abundance of sea grasses, Thalassia testudinum or Diplanthera wri.gh.tii. 

 Clam growth is not normally interrupted by winter temps as in northern waters. 

 Clams were carried by air from Milford, Conn, and planted in screened boxes. 

 Northern clams were 0.25 to 0.5 in long and hybrids of male M. aampeohiensis 

 and female M. meraenaria were 0.0625 to 0.125 in long. At Crystal River, in 

 salinities from 13 to 28°/oo, most clams were lost, and results were 

 inconclusive. At St. Petersburg, in salinities between 30 and 34°/°°, hybrids 

 quadrupled in size and northern species doubled in size from Nov. 1960 to 

 Feb. 1961. By June 1961 maximum length of hybrids was 1.5 in, northern 

 species 1.75 in. Survival of hybrids was 75%, but about half of the northern 

 species were lost. In Sarasota County northern clams grew about 1 in from 

 Apr. to Aug. 1960, when they were killed by fresh water. By mid-June 1961 

 hybrids planted in Nov. 1960 had grown to max lengths of 1.5 in and 

 northern clams to max 1.25 in, at salinities of 27 to 31°/°o. Clams on open 

 bottom grew faster than those protected in boxes. At Sugarloaf Key northern 

 clams at the end of May 1961 ranged from 0.3 to 0.7 in long, and about half 

 had survived.' Hybrids were all lost. At Sebastian in Indian River County 

 50% of hybrids and 10-15% of northern clams were dead 7 days after planting 

 in Nov. 1960. By mid-June 1961 max length of hybrids was 1.25 in, of 

 northern clams 1.375 in. Salinities were 21 to 29°/°° • At Oak Hill in 

 Volusia County, at salinities 23 to 32°/ 00 , except during heavy rains, 

 hybrids and northern clams had nearly doubled in size by mid- Jan. By 

 mid-May 1961 both groups were 1 in long. Mortalities in this area were 

 relatively low. - J.L.M. 



2048 



Woodwell, George M. , Charles F. Wurster, Jr., and Peter A. Isaacson. 1967. 



DDT residues in an East Coast estuary: A case of biological concentration 

 of a persistent insecticide. Science 156(3776): 821-823. 



Samples of water, plankton, Crustacea, bivalve mollusks, insects, saltmarsh 

 plants, fishes, and birds from Carmans River estuary, Long Island, N.Y. were 

 analysed for DDT, DDE, and DDD. Residues of DDT varied from 0.00005 ppm wet 

 weight of whole organism in water to 75.5 ppm in ring-billed gull, Larus 

 delawarensis . In general, values were lowest in invertebrates and plants, 

 intermediate in fishes, and highest in birds, but variation was considerable. 

 Meraenaria meraenaria had 0.42 ppm in the proportions DDT 71%, DDE 17%, and 

 DDD 12%. - J.L.M. 



2049 



Wright, Anne McCoy, Merilyn Moorhead, and J. H. Welsh. 1962. 



Actions of derivatives of lysergic acid on the heart of Venus meraenaria. 

 British J. Pharmacol. Chemother. 18(2): 440-450. 



Lysergic acid derivatives showed a wide spectrum of action on isolated heart 

 of V. mercenaria. Lysergic acid diethylamide had an exciter effect resembling 

 closely that of 5-hydroxytryptamine (5-HT) . Methysergide failed to excite, 

 even at high concentrations, and inhibited the response to 5-HT in a molar 

 ratio of 1:1. Other derivatives were intermediate in their actions. The 

 order of relative activities of lysergic acid derivatives on Venus heart was 

 tentative, partly because it was difficult to make repeated tests on a given 

 heart. Even if this were not so, it would be unwise to generalize on the 

 actions of these derivatives on other molluscan hearts, because pharmacology 

 of different classes and families show considerable variation. - J.L.M. 



568 



