Gillnet selectivity to roach, Rutilus rutilus, from the Szczecin Lagoon, Poland
نویسندگان
چکیده
منابع مشابه
Sexual ornamentation, androgens and papillomatosis in male roach (Rutilus rutilus)
According to the immunocompetence handicap hypothesis, males with attractive sexual ornamentation are more handicapped than their less ornamented rivals because of the immunosuppressive androgens required for the production of secondary sexual characters. Here we studied the predictions of the hypothesis in a wild cyprinid fish, the roach (Rutilus rutilus). We assayed (1) sexual ornamentation (...
متن کاملInvestigation the selectivity of gillnet used in Roach (Rutilus rutilus L., 1758) fishery in Uluabat Lake, Bursa-Turkey
The purpose of this study was determine the selectivity properties of gillnet used in Roach (Rutilus rutilus) fishery in the Lake Uluabat. In the fishery works, 7 different gill net which were 100 meters in length and 32, 40,50, 60,70,80 and 90 mmmesh size with a same thickness and depth of 50 mesh as vertically have been used. Field work was carried out monthly in a period of January 2011 and ...
متن کاملExtinction risk of exploited wild roach (Rutilus rutilus) populations due to chemical feminization.
A model that assesses risks posed by feminization to wild populations of roach was developed. A population life table matrix model that considered both sexes and a newly developed fertility kinetic function was applied to calculate the intrinsic population growth rate (lambda) of roach populations where males had been feminized. The maximum sustainable yield (MSY) was used to quantify the effec...
متن کاملIntraoligochaete development of Myxobolus intimus (Myxosporea: Myxobolidae), a gill myxosporean of the roach (Rutilus rutilus).
The infection with Myxobolus intimus Zaika, 1965 in the gills of the roach Rutilus rutilus (L.) from Lake Balaton was recorded in 28 out of the 39 fish examined. Developing and mature plasmodia were detected on the gills exclusively in the spring. The Myxobolus intimus infection was found only in 2- to 3-year-old fish. In histological sections, young plasmodia were found in capillaries of the s...
متن کاملFactors affecting between-lake variation in the occurrence of epidermal papillomatosis in roach, Rutilus rutilus (L.).
The theory of island biogeography predicts that the probability of a species occupying an island depends on a dynamic equilibrium between extinction and colonization. Epidermal papillomatosis is a disease manifesting as skin tumours on fish. We studied the factors affecting the occurrence of the disease in roach, Rutilus rutilus (L.), in 34 lakes. The results of discrimination analysis suggest ...
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ژورنال
عنوان ژورنال: Acta Ichthyologica et Piscatoria
سال: 2007
ISSN: 0137-1592,1734-1515
DOI: 10.3750/aip2007.37.1.03