gg U. S. BUREAU OF FISHERIES 



presentation of evidence pertaining to investigation of operations 

 and claims of Florida oyster promoting concerns; Virginia Commis- 

 sioner of Fisheries, studies of the reproductive condition of winter 

 dredged crabs from Chesapeake Bay; North Carolina Department 

 of Conservation and Development, practical procedure for continua- 

 tion of oyster rehabilitation program ; Duke University, construction 

 of biological laboratory at Beaufort, N. C, for studies of marine life 

 of this region; Union Carbide and Carbon Corporation, corrosion 

 tests with stainless steel cable under marine conditions. 



Laboratory facilities for marine research have been provided for 

 11 independent investigators from other institutions who were en- 

 gaged in the following studies: Dr. H. V. AVilson, professor in the 

 University of North Carolina, behavior of embryonic cells under 

 controlled conditions; Dr. A. S. Pearse, Dnke University, crustacean 

 parasites and marine ecology; Dr. W. C. George, University of 

 North Carolina, blood of Echinoderms and Annelids; Dr. Henry 

 Vander Schalie, University of Michigan, the mollusca of the Beaufort 

 area; Dr. H. H. Harkins, Fordham University, attachment of Cir- 

 ripedia to submerged surfaces; Fred F. Ferguson, University of Vir- 

 ginia, morphology of marine Rhabdocoeles ; W. Henry Leigh, Univer- 

 sity of Illinois, the parasites of marine fishes; Gordon H. Tucker, 

 University of North Carolina, regeneration in certain of the lower in- 

 vertebrates ; J. Albert Fincher, University of North Carolina, cell be- 

 havior and embryology of sponges ; John C. Ayers, Duke LTniversity, 

 respiration of Crustacea; George W. Wharton, Jr., Duke University, 

 gregarine development in mud crabs. 



Terrapin culture. The terrapin farm or hatchery operated at the 

 U. S. Fisheries biological station at Beaufort is the largest in the 

 world. It has produced more than 116,000 diamond -back terrapin 

 since the artificial propagation of this species was undertaken in 

 1909. During the summer of 1937, 11,783 baby diamond-backs were 

 hatched in the five concrete breeding pounds surrounding the station. 

 This brood after being cared for under protected conditions for a 

 period of approximately 9 months will be distributed throughout the 

 South Atlantic region in cooperation with the various State conserva- 

 tion departments. Just prior to 1931 the brood stock was increased 

 to 1,775 females and 440 males and since then the hatch of young 

 terrapin has ranged from 10.060 per year to a record production of 

 13,245 in 1935. Capt. Charles Hatsel has been in immediate charge 

 of this work since its inauguration. 



Though breeding of diamond-back terrapin under seminatural con- 

 ditions has been very successful, the general results indicate that each 

 adult female has produced an average of only 6.5 young per year 

 whereas twice this number should be expected according to previous 

 experiments with small lots of animals. During the summer of 1937, 

 experiments were conducted under the direction of Dr. Prytherch in 

 which the brood stock was distributed in the breeding pounds in 

 different concentrations and in varying percentages of each sex. It 

 was found that the ratio of males to females, though varying from 

 1 to 2 to over 1 to 6, had no noticeable effect on egg production in 

 the different pounds. The principal factor appears to be the de- 

 gree of crowding of the brood stock as shown by the results from 

 3 similar pounds in which the hatch per female was 3.0, 6.2, and 9.3 



