نتایج جستجو برای: fish reproduction
تعداد نتایج: 168650 فیلتر نتایج به سال:
the pollution of aquatic ecosystems may affect natural reproduction of fish populations by decreasing the fertilization efficiency. among the various sources of pollution, heavy metals are important group, being found in both freshwater and marine environment. the present study investigated changes of sperm characteristics of caspimyzon wagneri when exposed to manganese (mn). spermatozoids were...
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...
251 specimens of kutum fish caught by bony fish persine on the southern shores of the Caspian Sea (Mazandaran) during the years 2017-2019 were studied to study the growth trend of this species. In this study, maximum estimated length (L∞) and annual growth coefficient (K) of kutum fish were estimated 71.79 cm and 0.13, respectively. The results of natural reproduction of this species in Kheirud...
We used genetic parentage analysis of 6200 potential parents and 5497 juvenile offspring to evaluate the relative reproductive success of hatchery and natural steelhead (Onchorhynchus mykiss) when spawning in the wild between 2008 and 2011 in the Wenatchee River, Washington. Hatchery fish originating from two prior generation hatchery parents had <20% of the reproductive success of natural orig...
prozac alters reproductive performance and filial cannibalism in male fighting fish, betta splendens
background: fluoxetine (prozactm) is one of the most popular antidepressant that can be released to aquatic systems via sewage-treatment effluents. it is suspected to provoke substantial effects in the aquatic environment. methods: in spawning tanks, specimens were exposed to concentrations of 0 and 0.54 µgl-1 fluoxetine from male introduction until the larvae had hatched. prior to spawning, ne...
Success in aquaculture depends on the mass production and quality of juveniles. However, many fish species suffered high losses during the early stages of development. Therefore, in order to decrease mortality, produce a large number of healthy larvae is a fundamental issue. On the other hand, one of the micronutrients that can be effective in larvae health is ascorbic acid. During the embryoni...
The aim of the project is to assay the effectiveness of different values ofLHRH-a2 combined with carp pituitary extract in 3-stages way on reproduction indices of Arabibarbus grypus that belong to Cyprinidae family and is a native fish in Khuzestan province. Fifty individuals of fish in 4 treatments were studied. Control treatment were injected by 4mg/kg pituitary extracts, first treated: 4mg/k...
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