this research was conducted to study the length-weight and length-length relationships and condition factor of six cyprinid fish species viz. alburnus atropatena , barbus lacerta , capoeta capoeta , carrasius gibelio , romanogobio macropterus and pseudorasbora parva from zarrineh river (urmia lake basin, iran). a total of 188 specimens ranging from 2.9 to 21.4cm in total length and 0.22 to 176g...

primary man in trying to find food went everywhere. but by forming ranching arranged a chain of places and became emigrant. by happening industrial revolution, human life was centralized on one place.  places that base on its advantages make different biologic and behavioral types. forming cities in seaboard, river shore, boundary of mountains and champaign cause to make different cultures that...

Peripheral populations often experience more extreme environmental conditions than those in the centre of a species' range. Such extreme conditions include habitat loss, defined as a reduction in the amount of suitable habitat, as well as habitat fragmentation, which involves the breaking apart of habitat independent of habitat loss. The 'threshold hypothesis' predicts that organisms will be mo...

Environmental Flow Requirement (EFR) is defined as the flow that is necessary to ensure the existence of habitats in water resources systems. EFR is defined in rivers as flow index commonly. Tennant method is the most popular hydrological method in rivers and based on the historic flow data. The most common method of hydraulic rating method is the wetted perimeter method. Habitat simulation tec...

Knowledge of habitat requirements of aquatic animals plays an important role in fisheries and protection programs of aquatic ecosystems. Hence, this study was conducted to investigate the suitability indexes of habitat use and habitat suitability index (HSI) of Barbus cyri in its distribution range in Tootkabon River. A number of environmental variables, including elevation, water depth, river ...