نتایج جستجو برای: endangered fish

تعداد نتایج: 117273  

2014
Adam R. Wall Daniel Campo Regina Wetzer

We examined the potential utility of museum specimens as a source for genetic analysis of fairy shrimp. Because of loss of their vernal pool habitat, some fairy shrimp (including Branchinectasandiegonensis and Branchinectalynchi) are listed as threatened or endangered in Southern California by the United States Fish and Wildlife Service. Management of those species requires extensive population...

Journal: :Frontiers for Young Minds 2021

Conservation hatcheries are like luxury fish hotels that raise threatened and endangered nearing extinction in the wild. Raising controlled environment of conservation hatchery usually takes away issues caused population to dwindle first place. However, there is one problem: get used become wimpy, meaning they domesticated do not as well wild if returned natural environment. Managing genes way ...

2017
W. F. Frick E. F. Baerwald J. F. Pollock J. A. Szymanski T. J. Weller A. L. Russell S. C. Loeb L. P. McGuire

a Bat Conservation International, PO Box 162603, Austin, TX 78716, USA b Department of Ecology and Evolutionary Biology, University of California Santa Cruz, Santa Cruz, CA 95064, USA Department of Biological Sciences, University of Calgary, Calgary, AB T2N 1N4, Canada d American Wind Wildlife Institute, Washington, DC 20005-3544, USA e United States Fish and Wildlife Service, Endangered Specie...

2012
Lucas C. Barros Udson Santos José C. Zanuncio Jorge A. Dergam

The middle section of the lake basin of the Doce River in Minas Gerais State, Brazil is plagued by grave environmental problems, including the introduction of non-native fish, which reduces the biodiversity of this region. This study reports the presence of two newly-detected non-native species in the Doce River Basin. Sampling efforts included gill nets with mesh size of 3 to 12 mm (measured d...

Journal: :Ecology 2006
James A Estrada Aaron N Rice Lisa J Natanson Gregory B Skomal

We conducted stable 13C and 15N analysis on white shark vertebrae and demonstrated that incremental analysis of isotopes along the radius of a vertebral centrum produces a chronological record of dietary information, allowing for reconstruction of an individual's trophic history. Isotopic data showed significant enrichments in 15N with increasing sampling distance from the centrum center, indic...

Journal: :Journal of fish diseases 2017
J Barry M Newton J A Dodd D Evans J Newton C E Adams

Infection patterns of the invasive Anguillicola crassus nematode were investigated in a population of the European eel Anguilla anguilla where parasite invasion is very recent, Loch Lomond, Scotland. Intensity levels of the parasite were associated with differences in fish ontogeny and trophic ecology. Although eels foraged on both fish and invertebrates, individuals which were smaller and fed ...

Journal: :Archives of environmental contamination and toxicology 2013
T A Ryan A N Kohl D J Soucek T S Smith T M Brandt T H Bonner D M Cropek

Toxicity tests evaluated chronic and sublethal effects of fog oil (FO) on a freshwater endangered fish. FO is released during military training as an obscurant smoke that can drift into aquatic habitats. Fountain darters, Etheostoma fonticola, of four distinct life stages were exposed under laboratory conditions to three forms of FO. FO was vaporized into smoke and allowed to settle onto water,...

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...

Journal: :Environmental management 2001
L Pejchar K Warner

Resource managers are increasingly being challenged by stakeholder groups to consider dam removal as a policy option and as a tool for watershed management. As more dam owners face high maintenance costs, and rivers as spawning grounds for anadromous fish become increasingly valuable, dam removal may provide the greatest net benefit to society. This article reviews the impact of Endangered Spec...

Journal: :Biology letters 2017
Brad E Erisman Timothy J Rowell

Group choruses of marine animals can produce extraordinarily loud sounds that markedly elevate levels of the ambient soundscape. We investigated sound production in the Gulf corvina (Cynoscion othonopterus), a soniferous marine fish with a unique reproductive behaviour threatened by overfishing, to compare with sounds produced by other marine animals. We coupled echosounder and hydrophone surve...

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