Determination of chromosome number and structure of brown trout (Salmo trutta labrax, S. t. caspius, S. t. abanticus) and their hybrids distributed in Anatolia

In this study, chromosome numbers and structures of Salmo trutta labrax (L), S. t. caspius (C), S. t. abanticus (A) and their hybrits (AC, AL, LC, CA, LA, CL) were determined. Also differences in chromosome structures of these fish were defined by using different banding methods such as C-banding and Ag-NOR. Chromosome number for AA was 2n=80 and fundamental arm number (NF)=100. The diploid complement comprised 7 metacentric pairs (M), 3 submetacentric pairs (SM), 6 subtelocentric pairs (ST) and 27 Acrosentric pairs (A). Chromosome number and diploid complement for CC was 2n=80, NF=98, 7M, 2SM, 2ST, 29A; for LL 2n=80, NF=102, 8M, 3SM, 2ST, 27A. Chromosome number and diploid complement for hybrids 2n=80, NF=100, 8M+2SM+4ST+25A in a AC; 2n=80, NF=102, 8M+3SM+1ST+28A in AL; 2n=76, NF=98, 8M+3SM+3ST+29A in CA; 2n=78, NF=96, 7M+2SM+4ST+26A in CL; 2n=80, NF=100, 8M+2SM+7ST+28A in LA; 2n=80, NF=101, 9M+2SM+1ST+28A in LC. According to Ag-NOR banding results, a pair of NOR regions were observed on the telomere regions of SM chromosome's short arms of all groups and hybrids. Moreover, after C-banding, various numbers of constitutive heterochromatin region were determined either on the centromere or arms of some chromosomes.