ASYMMETRY OF MALE GONAD OF THE SEA TROUT (SALMO TRUTTA TRUTTAL.) IN THE FIRST YEAR OF LIFE
Journal Title: ELECTRONIC JOURNAL OF POLISH AGRICULTURAL UNIVERSITIES - Year 2009, Vol 12, Issue 2
Abstract
Paired gonads occur in the majority of teleostean fish species. In females a greater mass and fertility of the left one ovary has often been reported, while much less attenti on has been devoted to a comparative analysis of gonads in males. In this study an assessment of asymmetry of male gonads in sea trout in the first year of life has been made on the basis of their mass determination. The observations were made on 218 males, aged 5-6.5 and 12 months, caught in the streams located in north- western Poland. In the first year of life, immature and mature te stis shown asymmetry. In the majority of males studied (77%) t heleft gonad was greater. In 5% of the males the gonads were of the same size, while in 18% of the males the right was greater. The mass of the right gonad was on average 79% of the mass of the left testis. The difference in mass between left and right gonads was on average 14% of the mass of both gonads (21% of the larger gonad) and was statistically significant p<0.001. The statistically significant differences in mass between the left and right gonad were from 6-month old males. In the separatedgroups of male with a greater left gonad, the difference in ma ss between larger and smaller gonads was twice greater than in the group with the greater right gonad. Differences between mass of left and right gonads in immature and maturemales were similar (chi-squared test, p>0.05).
Authors and Affiliations
Katarzyna Dziewulska , Józef Domagała
Keywords
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