Use of diploid and triploid tench (Tinca tinca) blood as standards for genome size measurements

The ploidy level of 10 diploid and 10 induced triploid tench, Tinca tinca, was verified using flow cytometry to determine relative DNA content of DAPI‐stained erythrocyte nuclei. The C‐value (haploid nuclear DNA content; pgDNA nucleus⁻¹) of these same individuals was determined by means of Feulgen image analysis densitometry, in comparison to the chicken (Gallus gallus domesticus; 1.25 pg P < 0.05) standard, using three different approaches. Highly similar mean C‐values were obtained, thus confirming the possibility of using tench blood as a frequently used standard in European pond aquaculture for ploidy determination in fishes.