Czech J. Anim. Sci., 2005, 50(5):213-219 | DOI: 10.17221/4152-CJAS

Chemical composition of flesh of diploid and triploid population of tench (Tinca tinca, Linnaeus 1758)

H. Buchtová¹, L. Vorlová¹, Z. Svobodová^1,2, M. Flajšhans^3,4

¹ University of Veterinary and Pharmaceutical Sciences, Brno, Czech Republic

² University of South Bohemia České Budějovice, Research Institute of Fish Culture and Hydrobiology at Vodňany, Czech Republic

³ Joint Laboratory of Genetics, Physiology and Reproduction of Fish, Institute of Animal Physiology and Genetics, Academy of Sciences of the Czech Republic and University of South Bohemia České Budějovice, Research Institute of Fish Culture and Hydrobiology at Vodňany, Czech Republic

⁴ Department of Fishery, Faculty of Agriculture, University of South Bohemia České Budějovice, Czech Republic

The objective of this study was to determine differences in relevant parameters of the basic chemical composition of flesh (descriptors: dry matter - DM, crude proteins - CP, net proteins - NP and net muscle proteins - NMP, fat - F, ash - A) of communal stock of diploid (2n) and triploid (3n) tench (Tinca tinca L.) of the same origin, in relation to sex (F: female vs. M: male) and age (T₃: 36 months, after overwintering vs. T₃₊: 42 months, after one summer in the pond). Altogether 137 siblings of tench were studied. The basic chemical composition of flesh of 2n and 3n tench of T₃ age was found to be nearly the same. The only significant difference (P < 0.05) was found in DM content in diploids (5.7% higher DM content in females). Marked changes in the basic chemical composition were related to the increasing age of tench: after one summer in the pond (from T₃ to T₃₊) the DM content increased significantly in all groups of tench (by 5.4% in 2n females, P < 0.05; by 6.5% in 2n males, 9.9% in 3n females and by 7.4% in 3n males, all at P < 0.01). The content of nitrogenous substances was found to increase significantly (P < 0.01) in flesh of 2n males: CP by 3.2%, NP by 4.2% and NMP by 3.3% and in flesh of 3n males: CP by 7.0%, NP by 6.6% and NMP by 7.3%. Muscles of 3n females contained 107.3% higher fat content (P < 0.05). The proportion of ash decreased in 2n and 3n by 2.5% and 1.7%, respectively (P < 0.05). The flesh quality of T₃₊ tench after one summer in the pond was higher if compared with that of T₃ tench after overwintering. Related to the ploidy level, more favourable chemical composition of flesh and more favourable flesh quality were found for triploids of T₃₊ age.

Keywords: tench; genome polyploidy; dry matter; crude proteins; net proteins; net muscle proteins; fat; ash

Published: May 31, 2005  Show citation