The role of the pelvic fins in the copulatory act of certain poeciliid fishes

Por Clark, Eugenie, R.P. Kamrin

American Museum Novitates, (1509):1-14 07-may.-1951


" In adult poeciliid fishes there is a marked sexual dimorphism particularly in reference to body size, coloration, and fin structure. While considerable effort has been expended over the years in studying the structure and function of the gonopodium (modified anal fin of the mature male), relatively little attention has been directed to an understanding of the pelvic fins which also become modified as the males mature. In the latter, particularly the first and second rays of the pelvic fins show considerable specialization. It has been reasoned from the fin anatomy in such cyprinodont genera as Poecilia, Molliensia, Limia, Xiphophorus (Henn, 1916), and Lebistes (Purser, 1941; Fraser-Brunner, 1947) that the elongated pelvic fins of the males, acting in conjunction with the modified anal fin, help to form a tube through which spermatozoa pass during copulation. Observations on the sexual behavior of Lebistes reticulatus, and Xiphophorus hellerii (Christman, MS; Clark and Aronson, in press; Clark, Aronson, and Gordon, MS) show that during sexual activity, when the anal fin or gonopodium of the male is moved forward and to one side towards the female, the pelvic fin on that side is also coordinated with a forward motion. These studies support the hypothesis that the pelvic fins function in some manner during copulation "

Idioma: English

Clark, Eugenie & R.P. Kamrin. 1951. "The role of the pelvic fins in the copulatory act of certain poeciliid fishes". American Museum Novitates. (1509):1-14 (ffm00296) (resumen)