نتایج جستجو برای: eurasian perch
تعداد نتایج: 6356 فیلتر نتایج به سال:
this study was conducted in order to investigate genetic diversity and population structure of pike-perch in the northern part of iran. for this purpose, 207 adult pike-perches from four regions of the caspian sea watershed (talesh coasts, anzali wetland, chaboksar coasts and aras dam) were collected. dna was extracted and by using 15 pairs of microsatellite primers, polymerase chain reaction (...
780 BioScience • September 2005 / Vol. 55 No. 9 M ecologists and evolutionary biologists are familiar with the saga of the introduced Nile perch (Lates niloticus) in Lake Victoria. The explosion of the lake’s Nile perch population in the 1980s was monitored closely, because it coincided both with a fivefold increase in the economic value of the fishery (Reynolds et al. 1995) and with a halving ...
Food-storing corvids use many cache-protection and pilfering strategies. We tested whether Eurasian jays (Garrulus glandarius) reduce the transfer of auditory information to a competitor when caching and pilfering. We gave jays a noisy and a quiet substrate to cache in. Compared with when alone, birds cached less in the noisy substrate when with a conspecific that could hear but could not see t...
Simultaneous audio and video were recorded of a silver perch Bairdiella chrysoura producing its characteristic drumming sound in the field. The background noise contribution to the total sound pressure level is estimated using sounds that occurred between the pulses of the silver perch sound. This background contribution is subtracted from the total sound to give an estimate of the sound pressu...
The near-surface distribution of young-of-the-year perch was observed with a towed upward beaming echosounder system (SIMRAD EK60 with a circular 7◦ transducer). Perch aggregated densely in the epilimnion during daytime and dispersed evenly below the surface at night. Shoaling commenced in late June when perchmetamorphosed from the larval to juvenile stage. Average shoal widthwas 6.6m and avera...
There has been no previous parasitological survey of perch Perca fluviatilis in Turkey. Consequently, the objectives of the present study were to investigate the metazoan parasite communities of perch and also to calculate infection parameters of the parasites in a eutrophic lake. A total of 52 perch were collected seasonally from Lake Sığırcı in Ipsala, Turkey, between April 2009 and February ...
1. The effects of addition of juvenile perch (Perca fluviatilis) on the microcrustacean and rotifer communities associated with nymphaeid beds were studied, at three different plant densities [high (normal), medium (reduced by a half) and low (reduced to a third of normal)], in eighteen 2 m 3 1 m enclosures in a shallow lake. 2. At the low and medium densities of lilies, Daphnia densities were ...
The purpose of this study was to evaluate the effects of environmentally relevant dietary MeHg exposures on adult female yellow perch (Perca flavescens) and female zebrafish (Danio rerio) ovarian development and reproduction. Yellow perch were used in the study for their socioeconomic and ecological importance within the Great Lakes basin, and the use of zebrafish allowed for a detailed analysi...
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