نتایج جستجو برای: acipenseridae
تعداد نتایج: 71 فیلتر نتایج به سال:
Atlantic sturgeon (Acipenser oxyrinchus oxyrinchus, Acipenseridae) populations in the United States were listed as either endangered or threatened under the Endangered Species Act in 2012. Because of the endangered/threatened status, a better understanding of Atlantic sturgeon life-history behavior and habitat use is important for effective management. It has been widely documented that Atlanti...
Abstract The current data on the place and time of origin Acipenseriformes family Acipenseridae, as well their distribution in connection with history development sea river basins, are summarized. supposed areas initial radiation long-term habitation were eastern Laurasia a part modern Chita Region, Eastern Central Mongolia, northern northeastern China. Asia should also be considered Acipenseri...
effect of different photoperiodic regimes was evaluated on growth performance and survival rate of the beluga ( huso huso ) prelarvae and larvae. newly hatched prelarvae were stored in 5 round fiberglass 500‑l tank with different photoperiod (24l:00d, 18l:06d, 12l:12d, 06l:18 d, 00l:24d) till 50 days post hatch with three replicates. light intensity was 200 lux during the experiment. feeding wa...
Geoecology of the Ural River: landscape, climate, flora, and ichthyofaunal are given. Features air water temperature, winds, sources, balance detailed. Information about Sturgeon fishes Acipenseridae family, number which is critical, presented. The interaction natural conditions anthropogenic factors in creature spawning biotopes described.
A phylogenetic hypothesis is presented illustrating relationships among 23 extant sturgeon species based on nucleotide data from five mitochondrial genes (cytochrome b, NADH5, control region, 16S, and 12S). The tree supports our previous hypotheses regarding relationships among species of Acipenser and Huso. The introduction of Scaphirhynchus and Pseudoscaphirhynchus to the analysis does not ch...
مطالعات مختلف در خصوص تعیین جنسیت و مراحل رسیدگی جنسی ماهیان خاویاری به ویژه در مراحل اولیه زندگی نشان داد که برخی از روش ها مانند تکه برداری، سوند و آندوسکوپی علاوه بر هزینه بالا، سبب آسیب های شدید فیزیکی به ماهی می شوند. روش های مختلف ژنتیکی نیز فاقد کارایی لازم جهت تشخیص جنسیت تاس ماهیان می باشند. روش هایی چون اندازه گیری صفات مورفومتریک و تصویربرداری از سوراخ تناسلی از دقت اندازه گیری مناسب...
While the proliferation of the species-rich teleost fish has been ascribed to an ancient genome duplication event at the base of this group, the broader impact of polyploidy on fish evolution and diversification remains poorly understood. Here, we investigate the association between polyploidy and diversification in several fish lineages: the sturgeons (Acipenseridae: Acipenseriformes), the bot...
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...
early body shape changes of beluga sturgeon were studied using landmark-based geometric morphometric approach to recognize its allometric growth pattern. sampling was done from hatching up to 50 days post hatching (dph). left side of specimens were photographed using digital camera and nine landmark points were digitized on two-dimensional images. total length (ti) was measured using the softwa...
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