Determination of frequency distribution of oocytes at different maturity phases in the ovaries of roach, Rutilus rutilus (L.)
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چکیده
منابع مشابه
Factors 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 ...
متن کاملSexual 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 کاملSperm quality, secondary sexual characters and parasitism in roach (Rutilus rutilus L.)
According to sperm competition models, a male spawning in a disfavoured role should have spermatozoa with higher velocity but shorter longevity compared with a male spawning in a favoured role. Moreover, immunosuppressive androgens are needed to produce both secondary sexual characters and sperm cells. The ‘sperm protection’ hypothesis suggests that the immunosuppressive action of androgens has...
متن کاملHigh prevalence of zoonotic trematodes in roach (Rutilus rutilus) in the Gulf of Finland
The intention to increase roach (Rutilus rutilus) consumption is in focus for ecological and economic reasons in Finland. However, its safety as food has not been considered comprehensively. We collected and artificially digested 85 roach halves originating from the south-eastern coast of Finland, and found trematode metacercariae in 98.8% of the samples. Based on polymerase chain reaction (PCR...
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...
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ژورنال
عنوان ژورنال: Acta Ichthyologica et Piscatoria
سال: 2003
ISSN: 0137-1592,1734-1515
DOI: 10.3750/aip2003.33.1.04