نتایج جستجو برای: fish diversity
تعداد نتایج: 287954 فیلتر نتایج به سال:
The endangered Rio Grande silvery minnow persists as a remnant population in a highly fragmented and regulated arid-land river system. The species is subject to dramatic annual fluctuations in density. Since 2003, the wild population has been supplemented by hatchery-reared fish. We report on a 12-year (1999-2010) monitoring study of genetic diversity and effective population size (N(e)) of wil...
Cooperation is considered to be very important for an autonomous multiagent system (called MAS in short) composed of many autonomous agents. However, keeping a suitable combination of cooperation and diversity is considered to be more important for a MAS behaving in a dynamic environment. In this paper, as the examples of autonomous MAS, two species of fish schools with different cooperation an...
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...
More than 50% of Chinese mangroves were lost between 1950 and 2000 to habitat destruction, prompting an urge for conservation. To assess the importance of the protected Maowei Gulf mangrove estuary for fish population assemblage in the Beibu Gulf (China), we studied species composition and abundance of juvenile fish (including larvae) from July 2012 to June 2013. A total of 11 691 specimens wer...
While introductions and supplementations using non-native and potentially domesticated individuals may have dramatic evolutionary effects on wild populations, few studies documented the evolution of genetic diversity and life-history traits in supplemented populations. Here, we investigated year-to-year changes from 1989 to 2009 in genetic admixture at 15 microsatellite loci and in phenotypic t...
Coral reefs are in decline across the globe as a result of overexploitation, pollution, disease and, more recently, climate change. The impacts of changes in coral cover on associated fish communities can be difficult to predict because of the uneven dependence of reef fish species on corals for food, shelter or the three-dimensional structure they provide. We compared live coral cover, reef fi...
Swallenia alexandrae, Eureka Valley dune grass (Poaceae, Chloridoideae), is a narrow endemic known only from three localities in the Eureka Valley and adjoining Saline Range in the northern portion of Death Valley National Park (Inyo County, California). This monotypic genus is listed as endangered by the US Fish and Wildlife Service and as rare by the California Department of Fish and Game. Ge...
The implications of shallow water impacts such as fishing and climate change on fish assemblages are generally considered in isolation from the distribution and abundance of these fish assemblages in adjacent deeper waters. We investigate the abundance and length of demersal fish assemblages across a section of tropical continental shelf at Ningaloo Reef, Western Australia, to identify fish and...
To provide more morphological data of I. persa, in this study, morphological characteristics along with scales and otolith were studied. Fish samples were collected from Khorgo spring and transferred to the laboratory. Fish were classified into three class sizes based on standard length. Based on the results, the size of the first class was different in 12 relative traits but did not show a sig...
43 44 Title What is the impact of 'liming' of streams and rivers on the abundance and diversity of fish and invertebrate populations?
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