نتایج جستجو برای: rutilus rutilus caspicus
تعداد نتایج: 1051 فیلتر نتایج به سال:
Concern has been raised in recent years that exposure to wastewater treatment effluents containing estrogenic chemicals can disrupt the endocrine functioning of riverine fish and cause permanent alterations in the structure and function of the reproductive system. Reproductive disorders may not necessarily arise as a result of estrogenic effects alone, and there is a need for a better understan...
Understanding the environmental factors driving species-genetic diversity correlations (SGDCs) is critical for designing appropriate conservation and management strategies to protect biodiversity. Yet, few studies have explored the impact of changing land use patterns on SGDCs specifically in aquatic communities. This study examined patterns of genetic diversity in roach (Rutilus rutilus L.) to...
Identifying the relative importance of predation and resources in population dynamics has a long tradition in ecology, while interactions between them have been studied less intensively. In order to disentangle the effects of predation by juvenile fish, algal resource availability and their interactive effects on zooplankton population dynamics, we conducted an enclosure experiment where zoopla...
Species integrity can be challenged, and even eroded, if closely related species can hybridize and produce fertile offspring of comparable fitness to that of parental species. The maintenance of newly diverged or closely related species therefore hinges on the establishment and effectiveness of pre- and/or post-zygotic reproductive barriers. Ecological selection, including predation, is often p...
Abstract The aim of this study was to compare the susceptibility body deformities in juveniles 13 common European cypriniform fish, caused by intensive feeding with same commercial dry diet administered at 25°C according a similar schedule. final share individuals malformations differed considerably among species and 0.0-87.0%. Unaffected were only Barbus barbus (L.), Chondrostoma nasus Cyprinu...
This paper reports the results from mobile hydroacoustic surveys carried out between 1994 and 2018, to assess fish stocks in four impounded reaches, covering 19.8 km of River Thames, England. The data are complemented with electric fishing boom boat results, collected at same study reaches time periods. Hydroacoustic used inter-calibrated dual split-beam scientific echosounders, transducers bea...
The species composition of the ichthyofauna Samara River under influence man-made factors in Novomoskovsk district Dnipropetrovsk region is presented. environmental problem characterized, and on revealed. was analyzed based literature data, field ichthyological studies were also conducted to determine River. results technogenic modern realities have been obtained are summarized relation ichthyo...
Since the arrival of invasive quagga mussels Dreissena rostriformis bugensis in Lake Constance, significant changes zooplankton and benthic invertebrate community were observed. Five years later mussel has become dominating species community. Its effects on other components food web, especially those at higher trophic levels such as fish, remain unclear around world. To evaluate actual impact q...
شاه کولی(Alburnus chalcoides)، ماهی کلمه (Rutilus rutilus caspicus) و ماهی حوض (Carassius auratus auratus) از خانواده کپور ماهیان هستند. هدف از این تحقیق بررسی دستگاه گوارش ماهیان مذکور می باشد. بعد از تهیه نمونه ها، مجرا و ضمائم گوارشی ماهی ها خارج گردید و برای بررسی های هیستولوژی از رنگ آمیزی هماتوکسیلین- ائوزین (H&E) استفاده شد. سن این ماهیان بین 2 تا 3 سال بود. لوله گوارش هر سه ماهی شامل م...
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