نتایج جستجو برای: hatchery litter
تعداد نتایج: 15102 فیلتر نتایج به سال:
This study is situated within a national research program aimed at elucidating the multiple challenges faced by small coastal communities who are sensitive to the social and environmental events that shape and shift their livelihood. Decisions that affect these communities are often embedded within scientific discourse and neglect the diverse and rich locally situated knowledge that exists with...
Genetic diversity of two wild Kalibaus, Labeo calbasu populations and one hatchery stock was studied using random amplified polymorphic DNA (RAPD) method. The three 10–mer random primers (OPA01, OPB02 and OPC03) yielded a total of 26 reproducible and consistently scorable RAPD bands of which 15 (57.69%) were considered as polymorphic (P95) indicating a high level of genetic variation in all the...
Accumulating data indicate that hatchery fish have lower fitness in natural environments than wild fish. This fitness decline can occur very quickly, sometimes following only one or two generations of captive rearing. In this review, we summarize existing data on the fitness of hatchery fish in the wild, and we investigate the conditions under which rapid fitness declines can occur. The summary...
Allelic variation at 10 microsatellite loci was assayed in potentially wild Oncorhynchus mykiss 32 collected from 11 tributaries and three upper main stem river sites (n=547), and compared to steelhead 33 trout from the hatchery operated in the lower main stem river (n=333). The objective was to investigate 34 microgeographic genetic structure of wild O. mykiss , in the face of large-scale hatc...
The high loss of newly released hatchery-reared European lobster (Homarus gammarus) juveniles for stock enhancement is believed to be the result of maladaptive anti-predator behaviour connected to deprived stimuli in the hatchery environment. Our objective was to learn if an enriched hatchery environment enhances shelter-seeking behaviour and survival. In the "naïve" treatment, the juveniles we...
Captive breeding programs are widely used for the conservation and restoration of threatened and endangered species. Nevertheless, captive-born individuals frequently have reduced fitness when reintroduced into the wild. The mechanism for these fitness declines has remained elusive, but hypotheses include environmental effects of captive rearing, inbreeding among close relatives, relaxed natura...
Ž . Brown trout Salmo trutta L. stocking practices in French Mediterranean rivers often result in artificial secondary contact and introgression between substantially differentiated genomes. Single and joint segregation at five protein and four microsatellite loci were analysed in two back-crosses Ž . between hybrid females resulting from domestic=Mediterranean genitors and hatchery males in or...
Captive rearing often alters the phenotypes of organisms that are destined for release into the wild. Natural selection on these unnatural phenotypes could have important consequences for the utility of captive rearing as a restoration approach. We show that normal hatchery practices significantly advance the development of endangered Atlantic salmon (Salmo salar) fry by 30+ days. As a result, ...
The effective population size is influenced by many biological factors in natural populations. To evaluate their relative importance, we estimated the effective number of breeders per year (Nb) and effective population size per generation (Ne) in anadromous steelhead trout (Oncorhynchus mykiss) in the Hood River, Oregon (USA). Using demographic data and genetic parentage analysis on an almost c...
—Spawning date is a crucial life history trait in fishes, linking parents to their offspring, and it is highly heritable in salmonid fishes. We examined the spawning dates of coho salmon Oncorhynchus kisutch and chinook salmon O. tshawytscha at the University of Washington (UW) Hatchery for trends over time. We then compared the spawning date patterns with the changing thermal regime of the Lak...
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