Cyclical Changes in the Distribution of the Testis Lipids in the Common Frog, Rana temporaria

The annual cycle in the testis of the catfish

“…T urner [ 1919[ has described the presence of a cord of germ-cells outside the testis in Perea Jlavescens from which he believes that a new crop arises. Similar statem ents have been given by Foi.ey [1926] in Umbra lim i and Lofts and Marshall [1957] in Esox lucius. These workers could not determ ine the point of origin of the cells but Foley guessed that the source might be extra testicular.…”

“…In Ciarías batrachus the value of gonosomatic index is m aximum in August but decreases rapidly after Septem ber. In Perea jlavescens (Turner [1919]), Umbra limi (F oley [1926]), Gasterosteos aculeatus (Craig-Bennett [ 1931]), Enneacanthus obesas (H arrington 11956]) and Esox lucius (Lofts and Marshall [1957]) sperm atogonial pro liferation and sperm atogenesis are completed during autum n. No further gonadal activity has been recorded till spring, when sperm are shed from the lobules and spawning occurs. Bullough 11939] has reported the sperm atogonial proliferation during sum m er, the form ation of prim ary sperm atocytes till autum n and secondary sperm atocytes and sperm atozoa till spring.…”

Spermatogenesis and spermatology of some teleost fish species

“…It is supposed that spermatogenesis is continuous in male guppies in the laboratory because females seem to be gravid all year long (Rosenthal, 1952 ;Billard, 1966). In nature, spermatogenesis is seasonal in temperate zone species ; Atlantic salmon (Jones and Orton, 1940), brook trout (Henderson, 1962) and pike (Lofts and Marshall, 1957) show spermatogenesis in summer and the sea-bream in spring (Papadopol, 1962). In some cases, spermatogenesis may begin in autumn and finish in spring as in the stickleback (Craig-Bennett, 1931) ; it appears to also be seasonal in some subtropical and tropical species ( 3.…”

fflSTOLOGICAL CHANGES IN THE TESTES OF THE FISH Gerres oyena (Forsskal, 1775) DURING THE REPRODUCTIVE CYCLE IN SUEZ BAY, RED SEA, EGYPT

“…The most common arrangement of lobules would appear to be that of the radial type, which are converging on the spermatic duct. This arrangement has been described by Turner (1919), Lofts and Marshal (1957), Latif and Saady (1973), EL-Maghraby et ah, (1981), Zaki et ah, (1994), Asem (1995) and EL-Boray (1997). In G. oyena, the lobules run lengthwise with lateral communications, becoming evident during the prespawning and spawning periods, similar to the observation of Rastogi(1968).…”