نتایج جستجو برای: endangered fish
تعداد نتایج: 117273 فیلتر نتایج به سال:
The paddlefish (Polyodon spathula) is a primitive fish that is found in several large rivers of the Mississippi River drainage. The status of paddlefish populations in these large rivers is debatable due to several factors including habitat loss, contaminants and commercial fishing (Sparrowe 1986; Gundersen and Pearson 1992). The roe of female paddlefish is used to make domestic caviar and comm...
Reintroduction of endangered fishes to historic habitat has been used as a recovery tool; however, these fish may face competition from other fishes that established in their native habitat since extirpation. This study investigated the physiological response of tidewater goby, Eucyclogobius newberryi, an endangered California fish, when competing for food with threespine stickleback, Gasterost...
Abstract. We consider consumers’ preferences for food fish diversity in a multispecies fishery model. Studying both the long-run equilibria and the transitional dynamics of an open-access fishery we conclude that the outcome is generally less sustainable the stronger preferences for diversity are. We show that even without biological interactions the optimal landing fees for the different stock...
In the present study, the effect of successive milt collection was investigated on spermatological parameters and reproduction successes of wild and cultured endangered caspian brown trout. The milt collection was done 3 times with two weeks intervals. After milt collection, amount of milt was allocated for milt quality evaluation and reminders used for fertilization. According to results, in w...
Genotyping of endangered species is helpful for establishing and evaluating conservation strategies. Mitochondrial sequence data was analyzed from 541 individuals of a critically endangered fish, Acheilognathus typus from present-day range-wide localities to re-evaluate an in-progress restoration program around Lake Izunuma-Uchinuma, Miyagi, Japan. Acheilognathus typus showed low sequence diver...
In India, freshwater environments are experiencing serious threats to biodiversity, and there is an urgent priority for the search of alternative techniques to promote fish biodiversity conservation and management. With this aim, the present study was undertaken to assess the fish biodiversity within and outside a river protected area, and to evaluate whether the protected river area provides s...
Desert springs, which harbor diverse and endemic invertebrate assemblages, are often used as refuge habitats for protected fish species. Additionally, many of these springs have been colonized by invasive fish species. However, the potential impacts of recently established fish populations on invertebrate communities in desert springs have been relatively unexplored. We conducted a mesocosm exp...
The Endangered Species Act of 1973, as amended, assigns the U.S. Fish and Wildlife Service the responsibility for listing species of plants and animals in the United States whose existence is either threatened or endangered. After a species is listed, the Service is responsible for, among other things, developing recovery plans, reviewing proposed federal actions to ensure that they do not comp...
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