Analysis of growth, weight and relevant indices of diploid and triploid population of tench Tinca tinca (Linnaeus 1758)

This study determined biometric and weight parameters and relevant indices of diploid and triploid tench. Altogether, 137 siblings of tench were studied. The effect of ploidy level appeared in significantly better growth of triploids (P < 0.001) as to biometric [total length (TL), standard length (SL), body height (BH), body width (BW)] and weight [fish weight (FW), carcass weight (CW)] parameters of T-3 of both sexes and of T3+ females. The effect of ploidy level also appeared as significantly higher dressing percentage (DP; P<0.001) of triploid T-3 females compared with other groups, significantly higher gonad weight (GW) and gonadosomatic index (GSI; P<0.001) of diploid T-3 females, as well as GSI and hepatosomatic index of diploid T3+ females. The effect of sex appeared in significantly higher (P<0.001) biometric (TL, SL, BH, BW) and weight (FW, CW) parameters of T-3 females of both ploidy levels, as well as of triploid T3+ females. The effect of sex also appeared as significantly higher DP (P < 0.001) of males in diploid T-3 fish, as well as of males of both ploidy levels in T3+ fish and significantly higher GW and GSI (P < 0.001) of females in diploid T-3 fish, as well as of females of both ploidy levels in T3+ fish. This study shows evidence for faster somatic growth and bigger final weight of triploid populations of tench compared with diploids in both age categories T-3 and T3+.