نتایج جستجو برای: alosa braschnicowi
تعداد نتایج: 268 فیلتر نتایج به سال:
The Laurentian Great Lakes are large dynamic aquatic ecosystems with a diversity of available habitats and associated fish communities. The increasing prevalence of invasive species has influenced habitat associations of native species and altered trophic relationships throughout the food webs. We sought to identify habitat and biotic relationships associated with common nearshore fish abundanc...
Although predation by non-native alewife (Alosa pseudoharengus) on lake trout fry (Salvelinus namaycush) has been documented, whether or not emergent lake trout fry innately recognize alewives as predators is unknown. This study investigated the behavior of post-emergent, free-swimming lake trout fry in the presence of alewives. Study objectives were to determine (1) if fry respond to the prese...
Question: It is well established that predators can influence the structure and dynamics of prey communities and that changes in prey communities can drive predator evolution. Here we ask whether changes in prey communities, brought on by the effects of predators, can feed back to mould the evolution of predator foraging traits. Study system: We sampled lakes in Connecticut (USA) containing eit...
The timing of life history events in many plants and animals depends on the seasonal fluctuations specific environmental conditions. Climate change is altering regimes disrupting natural cycles patterns across communities. Anadromous fishes that migrate between marine freshwater habitats to spawn are particularly sensitive shifting conditions thus vulnerable effects climate change. However, for...
In a mesocosm experiment, we tested whether larval fish show an active behavioural response to hydrodynamic impacts. Exposing I to 3 week old allis shad (Alosa alosa) larvae to a pulsed wave regime, we found that already I week old larvae immediately adapt their microhabitat use and activity patterns at the onset of the wave pulses. The fish larvae in stantaneously increased their activity leve...
The analysis of net catches made in Absheron Gulfs of the Caspian Sea during 2011-2012 is provided. The ichthyofauna of Absheron Gulfs, including 26 species found in the North Gulf, and 33 species and subspecies found in the South Gulf was studied for the first time. A taxonomical and ecological diversity of the fish fauna of North and South Absheron Gulfs is characterized. The peculiarities of...
تحقیق حاضر با هدف مطالعه بررسی برخی از پارامترهای بیولوژیکی و محیطی و تاثیر آن ها بر روی میزان صید شگ ماهی خزری alosa caspia در سال 1394-1393، در حوزه جنوب غربی دریای خزر در استان مازندران انجام پذیرفت. در مجموع 481 نمونه در طول این دوره مورد بررسی قرارگرفت .نتایج نشان داد که میانگین طول چنگالی شگ ماهی خزری 89/30±73/259میلیمتر و 16/36±168 گرم بوده و رابطه طول و وزن شگ ماهی خزری به صورت w=0.0442...
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