SOME PREVIOUSLY UNRECOGNIZED ANATOMI- 

 CAL FACTS AND THEIR RELATION TO 

 FISH-CULTURAL PRACTICES* 



By Dr. William Converse Kendall 



Scientific Assistant, U. S. Bureau of Fisheries 



Washington, D. C. 



The present discussion pertains to the peritoneal mem- 

 branes of the abdominal cavity of salmonoid fishes, principally 

 those membranes connected with or having relation to the 

 ovaries and the deposition of ova. 



Ninety-six years ago (1824), Rathke described the ovaries 

 and oviducts of the various fishes, among which were certain 

 salmonoids. Nearly 60 years later (1883), Huxley studied 

 the European smelt {Osmerus eperlanus) and reviewed 

 Rathke's work, confirming his statements in respect to the sal- 

 mon, but in the case of the smelt correcting certain errors and 

 amplifying the description by demonstrating the presence of 

 oviducts, which all salmonoid fishes including the smelt were 

 supposed not to possess. For nearly 100 years erroneous con- 

 clusions derived from Rathke's inaccurate interpretation of the 

 structure and arrangement of the female reproductive organs 

 have been perpetuated in every published account or reference 

 to salmonoid genitalia. And fish-cultural practices pertaining 

 to salmonoids, based as they were upon error, have resulted in 

 apparently hitherto unexplainable conditions, such as a large 

 percentage of unfertilized eggs, monstrosities among the fry, 

 reduced Qgg production, sterility, and even mortality in the 

 brood stock. 



The fish-cultural error is embodied in the following quota- 

 tion from Cambridge Natural History, p. 258, where the writer 

 says of the Salmonidse : "The large size of the eggs, their lack 

 of adhesiveness, and the fact that they fall into the abdominal 

 cavity (italics mine), out of which they may be easily squeezed, 



• This paper was awarded the prize of $ioo in the annual competition by the 

 American Fisheries Society for the best contribution covering original biological work. 



