Showing 2 results for Histology
Volume 8, Issue 2 (10-2009)
Abstract
The Caspian sea as a unique habitat has accommodated Rutilus frisii kutum for as long as the course of history but has undergone extreme ecological & managerial disturbances over the recent centuries which has in turn, borought about dire consequences including the formation of a potentially fragile ecosystem. In fact, various researches undertaken on this issue has shown that the specter of such ominous changes in ecosystem and the living resources of the Caspian Sea loom near. The present study aims at investigating the sexual and biological aspects of fish &their sex organs in Rutilus f. Kutum along the southern coasts of the Caspian Sea. To this end, the fish and gonad samples of Rutilus f. kutum migrating to rivers & estuaries were collected & analyzed through sampling procedures based on fish gonad. Upon treating the samples with Bouin & the related preparations, (I.e. extraction of water, making from the sample them transparent, molding & doing them based on H&E method), , whereas Peterson correlation coefficient was applied for toxic variables. The results of the analysis shows that 45 percent of sampled fish with an average length of (349 58) mm weighing 564 334) were male and 54.4 were Females. The sexual maturity rate, as specified by the six stages analysis me Thad of Johnson’s (Johnson’s, 1970) in dictated the position of female in the stages: IV & V during March, April & June. 32% of female fish were in stage V & %68 in stage IV in March whereas the percentages of female fish in April was %87 in the stage V followed by %94 in the stage V during June.
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Volume 10, Issue 3 (2-2010)
Abstract
Abstract
In lizards spermatogenesis takes place in two different ways: seasonal and non-seasonal. In seasonal type usually found in temperate-climate lizards, the process of spermatogenesis is limited to a defined period of the year, whereas in non-seasonal type observed in tropical-climate lizards this process occurs continuously year-round. In this research the spermatogenesis activity was studied in species of Laudakia caucasia occur in central Zagros Mountains. To fulfill this task, we collected 34 specimens of this species from Norabad, Lorestan province, during two seasons of their biological activity. The specimens were then killed and their testes were removed. After measuring the testis dimensions the specimens were prepared for histological observations. The results obtained from morphometric, histometric as well as histological examinations showed that the spermatogenesis in this taxon is seasonal and contains two phases: active and inactive. The active phase which coincides with late spring to early summer is the period in which cells in seminiferous tubules are actively involved in sperm-making process and all shapes of spermatogenic cells are seen within the tubules. During the inactive phase which begins in late-summer and lasts until the next spring, no spermatozoids is seen in the tubules as the process of spermatogenesis has been ceased. However, in this period, the regeneration activity is taking place in the gonad and the animal is preparing for its next spermatogenesis season.
