564 Bashford Dean Memorial Volume 



FEMALE REPRODUCTIVE ORGANS OF CERTAIN HIGHER SHARKS 



AND VARIOUS RAYS 



For the trilled shark, Chlamydoselachus, it has been shown that unilateral functioning 

 of the rpproductive organs is the general rule, that the right ovary and oviduct are uni' 

 formly fertile, but that rarely are both organs on the left side also functional. I have made 

 some studies on this subject of unilateral functioning of reproductive organs based on 

 dissections of sharks and rays at the U.S. Fisheries Laboratory at Beaufort, N. C, and in 

 the reports on these (Gudger, 1912, 1913) I have given references to a number of articles 

 bearing on this subject. To all these the interested reader is referred. 



The records of my studies on the reproductive organs of sharks and rays dissected at 

 Key West and at Dry Tortugas, Florida, while a guest-investigator at the marine labor- 

 atory of the Carnegie Institution of Washington, have never been published. Since some 

 of these notes bear directly on the subject in hand, and particularly since one of the sharks 

 (Ginglymostoma cirratum) in its eggs and reproductive apparatus shows certain marked 

 likenesses to these structures in Chlamydoselachus, it seems well to quote from these 

 notes here. 



OVARIES AND OVIDUCTS OF SOME FLORIDA SHARKS 



Since the sharks examined in southern Florida show the least departure from their 

 early ancestors in the bilaterality ot their reproductive organs, they will be studied first. 

 The first departure from bilaterality like that noted in Chlamydoselachus has to do with 

 the ovary. 



The Nurse Shark, Ginglymostoma cirratum. — In eight dissected female specimens of 

 this large, flat-bodied, sluggish, shallow-water shark with a large abdomen, both oviducts 

 were always functional, but in each fish the right ovary only was functional. The fish were 

 adults about 8 ft. in length, "over all". One had in the right ovary "30 eggs the size of 

 small oranges (equatorial diameter=60-65 rmn.)". Another had 33 ripe eggs in the right 

 ovary. Still another had ''right ovary enormously enlarged with 40 eggs size of billiard 

 balls, some about 6 in. ui circumference. These would have filled a peck measure or an 

 ordinary water bucket". Three had "right ovary full of gaping pits from which ripe eggs 

 had been erupted". Nearly all these enlarged right organs were median in position, while 

 of the left ovary my notes say "insignificant in size", "hardly recognizable", "had to be 

 hunted for". Not one left ovary had any eggs. It is to be regretted that none of these 

 huge right ovaries was measured. 



Various Other Florida Sharks. — The large, active, voracious tiger shark, Galeocerdo 

 tigrinus, has the oviducts bilateral and functional. In four fish the left ovary was generally 

 small and always non-functional, the right large, and functional with eggs in the anterior 

 part. I have notes for three species of the requin shark, Carcharhinus. In four specimens 

 of C. ohscurus with bilateral functional oviducts, the left ovary was "small", "very small", 

 "reduced"; while the right was always large and functional. In one 8-ft. fish, it w^as 2 ft. 

 10 in. long with 12 eggs, .5 to 1 in. in diameter. In one specimen of C. falciformis, my 



