نتایج جستجو برای: fish distribution
تعداد نتایج: 706269 فیلتر نتایج به سال:
Recent studies in streams and ponds have demonstrated that the distribution and biomass of aquatic organisms can be estimated by detection and quantification of environmental DNA (eDNA). In more open systems such as seas, it is not evident whether eDNA can represent the distribution and biomass of aquatic organisms because various environmental factors (e.g., water flow) are expected to affect ...
iran contains 33 named endemic fish species, which together with undescribed taxa, approximates one-third of the ichthyofauna. endemism in relatively large species such as fishes, which are better known systematically than other taxa, can often serve to indicate areas in need conservation. an analysis of endemicity is given in terms of systematics, distribution and ecology.
the systematics, morphology, distribution, biology, economic importance and conservation of the freshwater eel ( anguilla anguilla ) of iran are described, the species is illustrated, and a bibliography on this fish in iran is provided. the species is found in the caspian sea basin as an exotic.
Effective conservation of fish species of greatest conservation need (SGCN) requires an understanding of species-habitat relationships and distributional trends. Thus, modeling the distribution of fish species across large spatial scales may serve as a potentially valuable tool for conservation planning. Our goals were to evaluate the status of 10 Iowa fish SGCN in wadeable Iowa streams and tes...
the major lymphoid tissues in teleost fish are the kidneys, thymus, spleen and mucosa-associatedlymphoid tissue including the skin, gills and intestine. the head of kidney (pronephros) is an importanthaematopoietic organ and has morphological similarities with the bone marrow in higher vertebrates. in thisstudy, during 12 months from august 2002 to july 2003, 120 grass carp (10 fish/month) were...
The over-arching goal of this project was to investigate the processes affecting the productivity of capelin and walleye pollock, important forage fishes in the Gulf of Alaska (GOA). The first objective was to investigate the key physical processes by comparing the distribution of fish with oceanographic properties and the distribution of prey. The second objective was to investigate the potent...
Effects of climate change on animal behavior and cascading ecosystem responses are rarely evaluated. In coastal Alaska, social river otters (Lontra Canadensis), largely males, cooperatively forage on schooling fish and use latrine sites to communicate group associations and dominance. Conversely, solitary otters, mainly females, feed on intertidal-demersal fish and display mutual avoidance via ...
Subarctic Siberian freshwater ecosystems are unique due to severe climatic conditions and strong seasonal changes of water supply, temperature and nutrient availability. In this work we evaluated the relative influence of the illumination level linked with the diurnal cycle, local environmental heterogeneity and water level changes during the receding flood on the distribution and migrations of...
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