The Male Reproductive Organs of Some Common Crabs 

 of Puget Sound 



Nathan Fasten, 

 University of Washington, Seattle. 



During the past summer the writer, while stationed at the Puget 

 Sound Marine Station, collected various Brachyurans for the purpose 

 of studj'ing their spermatogenesis. The forms which were found to be 

 in particularly good condition during the months of June and July 

 were the common edible crabs, Cancer productus and Cancer magister; 

 the decorative crabs, Hyas lyratus and Oregonia gracilis; the purple shore 

 crab, Haemigrapsus nudus; the helmet crab, Telmessus chiragonus; and 

 the kelp crabs, Epialtus productus and Pugettia gracilis. Aside from 

 gathering testicular material of these forms for cytological study, at- 

 tention was also directed to the gross structure of the male reproductive 

 organs, and these latter findings are set forth in this publication. 



• The reproductive organs of the male crabs are located in the 

 chamber of the ceijhalothorax, and when fully developed they occupy a 

 goodly portion of this cavity. The organs lie directly below the heart 

 and above the digestive glands, or the so-called liver. The testis (Figs. 

 1-4 and 6-9, t), which comprises the main part of the male reproductive 

 organs, is bilobed and profusely tubular in structure. Each testicular 

 lobe is found in the upper part of the cephalothoracic region, running 

 laterally along the stomach. Both lobes unite in the median plane of 

 the body, underneath the anterior portion of the heart (Figs. 1-1 and 

 6-9, .r). Near this junction point two slender tubes make their origin, the 

 so-called vasa deferentia (Figs. 1-4 and 6-9, v. d.), one tube originating 

 from each testicular lobe, and these run posteriously to the base of the 

 fifth pair of walking legs, where they open to the outside. The position, 

 shape and size of the various male reproductive elements are shown in 

 figures 1-9 of plates 4-6. 



In Cancer productus the testicular lobes (Fig 1, t) are very well 

 developed and occupy a larger portion of the cephalothorax than the 

 same elements in Cancer magister (Fig. 2, t). However, in the latter 

 the union between the lobes of the testis is developed to a greater extent 

 than in Cancer productus (compare Figs. 1 and 2, .r). The vas deferent 

 ducts of both species (Figs. 1 and 2, v. d.) are coiled, straight tubes 

 running to the base of the fifth pair of walking legs. In Haemigrapsus 



(35) 



