Morphological changes in the sexual organs of the pulmonates were observed throughout a year and correlated with reproductive-cycle periods. Reproductive-organ weights of the snail Megalobulimus abbreviatus were recorded seasonally and gonad sections were analyzed morphologically. The weights were used to obtain the organosomatic index. Mean oocytic diameter and oocytic maturation index were ba...

Seasonal changes in the reproductive activity of the adult male viscacha (Lagostomus maximus maximus) were investigated during the annual reproductive cycle. Assays of heterologous in vitro binding between compatible gametes were used to evaluate the ability of viscacha spermatozoa to achieve primary binding during its annual reproductive cycle. Sperm were collected by mincing cauda epididymis ...

Freshwater fish that live exclusively in rivers are at particular risk from fragmentation of the aquatic system, mainly the species that migrate upriver for reproduction. That is the case of Salminus hilarii, an important migratory species currently classified as "almost threatened" in the São Paulo State (Brazil), facing water pollution, dam construction, riparian habitat destruction and envir...

Morphometric changes in body condition, liver, sonic muscle and gonadal development associated with the annual reproductive cycle and behaviour of the intertidal-nesting male plainfin midshipman Porichthys notatus were investigated. Body condition of type I males rapidly increased during the pre-nesting (PN) period, peaked at the beginning of the summer nesting cycle and then gradually declined...

shirbot ( barbus grypus ) is one of the species in south and southwest of iran which is greatly favorable to residents of the region. unfavorable ecological conditions in habitat of this species and overfishing have led to the reduction of the population of shirbot. therefore, to restore the natural stock of this species, identifying its reproductive cycle associated with its habitat is of a gr...

the aim of this investigation was to study macroscopic and microscopic structures of ovaries in barbus grypus of karoon river and their changes during annual maturation cycle. for this purpose, 120 adult  b.grypus with a mean weight of 835.0 to 1012.0 g, were caught from karoon river and transferred alive to the laboratory. after biometrical studies, the weights and morphological appearances of...

Satish Kumar Gupta and Biswa Ranjan Maiti (1996) Histological and histochemical studies of the postovulatory follicles during the annual reproductive cycle including nesting cycle of a wild avian species, the pied myna, Sturnus contra contra L. Zoological Studies 35(4): 292-295. The post-ovulatory follicles were studied during the annual reproductive cycle and nesting cycle of the pied myna, St...

To describe the morphological and histological changes during the annual reproductive cycle of the gonads of Cyprinion tenuiradius, a total of 341 specimens (102 female and 235 male specimens) were collected monthly from the Rudbal River (in the Qarah Aghaj sub-basin, the Persian Gulf basin), Firuzabad, Fars Province, southern Iran. The randomly sampling was adequate to collect males and female...