PROGRESS IN BIOLOGICAL INQUIRIES, 1935 421 



No correlation has been noticed between either the temperature or 

 salinity of the water and starfish distribution, but the distribution is 

 practically limited to those areas where shells are present on the 

 bottom. Shells were found at 110 of the 141 stations, 89.9 percent of 

 the starfish population being confined to these shell-covered areas. 

 The greatest concentration of starfish was found in the extreme 

 western part of the sound on the Long Island side on abandoned 

 oyster beds, and bottoms covered with dead shells. Kesults of the 

 surveys are of considerable practical importance for they disclosed 

 the presence of great numbers of starfish on bottoms which are 

 neglected by the oystermen. 



Although a few specimens of Asterias vulgaris and Ilenricia san- 

 guinolenta were found, Asterias forhesi is by far the predominating 

 species of starfish found in this region. 



Throughout the year the majority of starfish taken were of medium 

 size, 2 to 5 inches in diameter, the size distribution being markedly 

 similar for all surveys. The slight increase in the proportion of 

 small starfish found in the winter survey is due to appearance of 

 the 1935 crop. 



Although field surveys have demonstrated a certain stability in the 

 starfish population of this area, a direct attempt to study the move- 

 ments of starfish seem.ed to be desirable. After experiments had 

 shown all forms of tagging to be unsuccessful, a method of vital 

 staining was developed and successfully employed. On November 19, 

 approximately 15,000 starfish stained with nile blue sulphate were 

 released at a know^n point in the sound. Since then extensive map- 

 pings have shown that migration is evidently slow, as in 2 months 

 the most distant blue starfish were found only about one half a 

 nautical mile souih and west from the point of release. Five months 

 later the starfish were still holding the blue color although a few 

 were somew^hat faded. 



Laboratory studies on the condition of starfish gonads showed that 

 in November there is an increase in gonad size, apparently in prepa- 

 ration for next year's sj:>awning. In Long Island Sound the gonads 

 appear to be mature before January, while near Woods Hole, Mass., 

 maturity is not reached until late February or early March. It has 

 been found that A. forhesi spawns when the temperature of the water 

 reaches 20° C, j^rovided the gonads are mature. Spawning in Long 

 Island Sound first occurs about June 26-28, and continues until 

 August 20. 



Studies of the development of the larvae under laboratory condi- 

 tions showed the larval period lasts 21 days at an average temperature 

 of 20-21° C, Setting continued from July 15 until September 9, 

 taking place at depths from mean low water to 70 feet. 



A protozoan parasite, Orchitophyra steUarwm Cepede, has been 

 found in the gonads of the male Asterias forhesi^ occurring in about 

 1 of every 15. It causes a great reduction in the number of sperma- 

 tozoa in the follicles of the testis, often inducing total sterility. Work 

 is now in progress to study the life history of this organism and its 

 mode of infecting starfish. 



New Jersey and Delaware Bay section. — The principal aim of the 

 Bureau's work in New Jersey is the control of the oyster drills, 



