Some of these clams had discharged spermatazoa at this time. Definitive 

 males and females became distinguishable in September of their second year, 

 after they have spawned as males. In males a second period of spermato- 

 genesis begins in autumn and continues at a reduced rate in winter. Many 

 small ovocytes are retained by the male sexual gland. Gonads of clams to 

 become females after their male phase, remain empty and distended through 

 winter. Ovogenic activities began in spring when water temperature 

 approached 15°C. Three true hermaphrodites were found in 650 clams studied. 

 - D.L. 



1105 



Loosanoff, Victor L. 1937. 



Seasonal gonadal changes of adult clams, Venus mevaenaria (L.). Biol. 

 Bull. 72 (3) : 406-416. 



Spawning of hard clam in Long Island Sound was completed at the end of 

 August or early September. Post-spawning males began gametogenetic 

 activities by late September or early October and continued until 

 hibernation in mid-December when water temperature was about 5°C. Except 

 for a brief post-spawning period, mature adult males contain mature 

 spermatazoa every season of the year. Soon after female clams discharged 

 the bulk of their ripe eggs, ovogenetic activities began. Ovocytes con- 

 tinued growing rapidly in late fall and growth occurred although at a 

 much reduced rate during winter. By the end of May, the females are 

 sexually mature and will discharge their eggs when water temperature is 

 at the point which induces spawning. - D.L. 



1106 



Loosanoff, Victor L. 1937. 



Spermatogenesis in the hard-shell clam (Venus mevaenaria LinnaeusJ . Yale J. 

 Biol. Med. 9: 437-442. 



Describes in detail, for the first time, with illustrations, the various 

 stages of spermatogenesis in quahogs. - J.L.M. 



1107 



Loosanoff, Victor L. 1939. 



Effect of temperature upon shell movements of clams, Venus mereenaria (L.). 

 Biol. Bull. 76(2): 171-182. 



An apparatus which measures and records shell activity of bivalves was 

 described. Forty-seven hard clams attached to the apparatus for 399 days 

 were subjected to temperatures from -1 . 0°-28 . 0°C . The length of time that 

 shells remained open partly depended on water temperature. Hibernation 

 began when water temperature was decreased to 5.0 and 6.0°C. In the range 

 3.9°-10.9°C, the average time shells remained open increased from 4 to 88% 

 of the total time with increasing temperature. There was no such correlation 

 in the temperature range 11. 0-27. 9 °C, in this range, shells were open 69-90% 

 of total time. Clams remained open 90% of total time at temperatures 21.0- 

 22.0°C. There was considerable variation in behavior among clams under 

 identical environmental conditions. - D.L. 



1108 



Loosanoff, Victor L. 1941. 



Pearl in quohog (sic). Am. Naturalist 75(759): 399-400. 



Well-formed, lustrous pearls (or pearls of any kind) , are very rarely found 

 in hard clams, probably because the edge of the mantle is firmly attached to 

 the shell along its pallial line. This excludes foreign particles which 

 might serve as a nucleus. A clam at least 5 yrs old taken from a tributary 

 of Milford Harbor, Conn, contained a pearl of perfect oval shape 1.4 cm long, 

 1.1 cm wide, and weighing 3.1 g. It was milky white with a delicate pink 



309 



