The first findings of the differences in complete blood count between diploid and triploid tench, Tinca tinca L.

The aim of this work was to evaluate differences in complete blood count of diploid and triploid tench and concentration of total protein in blood pla sma of these fish. Haematological examination of 78 specimens of three-year -old tench, consisting of 21 triploids and their 57 diploid siblings was pe rformed in July 1996. Analysis of variance test confirmed a significantly l ower erythrocyte count in triploids (P < 0.01), as well as a significantly lower haemoglobin content (P < 0.05), significantly higher medium corpuscul ar volume, higher medium corpuscular haemoglobin and lower medium corpuscul ar haemoglobin concentration (all at P < 0.01) compared to diploids. The ha ematocrit value of triploids was insignificantly lower compared to diploids . The differences of erythrocyte nuclear area, perimeter, average size, maj or axis and aspect ratio between diploids and triploids were found signific ant at P < 0.01 and the effect of ploidy level on these dimensions was cons idered highly significant (P < 0.0001). No effect of ploidy level was prove n for erythrocyte nuclear minor axis. The leukocyte count of triploids was insignificantly lesser compared to diploids. Triploid tench were found of s ignificantly lower concentration of total protein in blood plasma compared to diploids (P < 0.01). Triploid tench could be hypothesized to have a lowe r oxygenation capacity of blood, as well as a lower non-specific immunity l evel compared to diploids. Insignificantly higher erythrocyte count, haemog lobin content, haematocrit value, and significantly higher concentration of total protein in blood plasma (P < 0.01) was reported for diploid females compared to males.