New York, N.Y. : American Museum of Natural History
Abstract
20 p. : ill. ; 24 cm.Includes bibliographical references (p. 18-20)."Serranid fishes exhibit several types of hermaphroditism. 2. Members of the genus Serranus, and its relatives Hypoplectrus, Diplectrum, and perhaps others, are synchronous hermaphrodites, with the gonad divided into separate male and female zones. There are separate ducts for the eggs and sperm. 3. Members of the genera Epinephelus, Mycteroperca, Alphestes, CephalophoIis, and Petrometopon are protogynous hermaphrodites in which the presumptive testicular tissue is scattered as crypts throughout the epithelial layer of the ovarian lamellae. Precocious sperm are formed in some crypts during the juvenile and female phases. Transformation to the male phase is accomplished by proliferation of these crypts, accompanied by the development of sperm sinuses in the gonad wall. The ovarian lumen remains in the male phase, but there is a separate sperm duct. 4. The genus Rypticus has a type of sexuality intermediate between that of Epinephelus and that of Serranus. Rypticus is a protogynous hermaphrodite, with male tissue confined to narrow bands on each side of the oviduct. Male and female elements are intermingled in this region. 5. Although the sexual pattern of Rypticus is intermediate between that of Serranus and that of Epinephelus, it is unlikely that it gave rise to Epinephelus. Rather, Rypticus must be regarded as a specialized derivative of an intermediate ancestor. 6. Hermaphroditic serranids have the acinus type of testes. Gonochoristic Serranidae of the genus Roccus have testes of the radial type. The spermatogonia line connective tissue tubules which radiate from the sperm duct. Their relationship to the marine Serranidae, on the basis of this evidence, does not seem to be particularly close"--P. 17-18