نتایج جستجو برای: acipenser
تعداد نتایج: 1483 فیلتر نتایج به سال:
The associations were quantified between daily and interannual variation in the timing of a closed population of lake sturgeon Acipenser fulvescens migration and arrival at spawning sites with stream environmental and lunar covariates. Spawning data were gathered from 1262 fish in Black Lake, Michigan 2001 to 2008 and by video monitoring 2000 to 2002. Sex-specific variation in responses to exte...
Little is known of the swimming capacities of larval sturgeons, despite global population declines in many species due in part to fragmentation of their spawning and rearing habitats by man-made water-diversion structures. Larval green (Acipenser medirostris) and white sturgeon (Acipenser transmontanus) inhabit the highly altered Sacramento-San Joaquin watershed, making them logical species to ...
Acipenser oxyrinchus is considered extirpated in Europe, but numerous breeding populations still exist on the Atlantic coast of North America. An adult female A. oxyrinchus, 2500 mm total length and 120 kg wet weight, was accidentally fished on 24 November 2010 near the coast of Gijón, Asturias, Spain. The fish was identified by its morphological pattern as well as by mitochondrial and nuclear ...
The present work reports behavioural responses by young-of-the-year (21-30 cm) Atlantic sturgeon Acipenser oxyrinchus oxyrinchus and shortnose sturgeon Acipenser brevirostrum to nine binary combinations of dissolved oxygen saturation (40, 70 and 100%), temperature (12, 20 and 28°C) and salinity (1, 8 and 15). Both species showed no acclimation effects and similar discrimination and avoidance re...
Histological examination of thymi from juvenile Acipenser ruthenus and Acipenser brevirostrum after haematoxylin and eosin staining revealed the presence of Hassall’s corpuscles, in a scattered distribution within the thymic medulla in two of seven, and one of nine examined specimens, respectively. Morphologically, the Hassall’s corpuscles were of the juvenile and premature type and no degenera...
Worldwide, sturgeons (Acipenseridae) are among the most endangered fishes due to habitat degradation, overfishing, and inherent life history characteristics (long life span, late maturation, and infrequent spawning). As most sturgeons are anadromous, a considerable portion of their life history occurs in estuarine and marine environments where they may encounter unique threats (e.g., intercepti...
This study was carried out to investigate the supplemental effects of dietary garlic extract (GE) on growth performance of juvenile sterlet sturgeon (Acipenser ruthenus). The first experiment was designed to determine the optimum levels of garlic extract as growth promoter during 10 weeks. Three groups (two replicates/group) of 240 fish with mean body weight of 85 g were fed with diets containi...
During teleost ontogeny the larval and embryonic stages are key stages, since failure during this period of tissue differentiation may cause malformations, developmental delays, poor growth, and massive mortalities. Despite the rapid advances in sequencing technologies, the molecular backgrounds of the development of economically important but endangered fish species like the Atlantic sturgeon ...
Russian ( Acipenser gueldenstaedtii), Persian ( A. persicus) and Siberian ( A. baerii) sturgeons are closely related 'Ponto-Caspian' species. Investigation of their population structure is an important problem, the solution of which determines measures for conservation of these species. According to previous studies, 'baerii-like' mitotypes were found in the Caspian Sea among 35% of Russian stu...
Immersing Siberian sturgeon fry of an average body mass of 40 ± 4 g in epin solution (0.1 mg l -1 ) resulted in an increase of ceruloplasmin level over the entire experimental period (P < 0.001). The differences between the treated and control groups gradually increased reaching the maximum in the fourth and fifth weeks of the study when average levels of ceruloplasmin in the epin-treated group...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید