Karyotype analysis in Schizothorax zarudnyi from Hamoon lake, Iran

The karyotype and chromosomal characteristics of (anjak, hamoon mahi, shir mahi) Schizothorax zarudnyi (Nikolskii, 1897) in Hamoon Lake of Iran were investigated. The examination of 85 metaphases spread prepared from 20 fingerling specimens indicated that the chromosome numbers of this species was found 2n=96 and the arm number was determined as NF=142. The prepared karyotype of this species was consisted of 9 pairs of metacentric (M), 14 pairs of submetacentric (SM) and 25 pairs of subtelocentric (ST) chromosomes. The chromosome formula can be stated as 2n = 9m + 14sm + 25st. Karyological parameters shown that centromeric index, arm ratio, relative length and so length variation range of chromosomes of this fish are between 25.00 - 49.24, 1.03 - 3.55, 0.88 - 4.13 and 14.57 - 67.70 respectively and total length of chromosome is 1639.16 μm. The largest chromosome in this species is a pair of the submetacentric chromosome. The sex chromosomes were cytologically indistinguishable. With respect to the number of S. zarudnyi chromosomes and resistance of this fish to the environmental conditions, it seems to be tetraploid origin fish. This study may provide the first knowledge on chromosome analysis in S. zarudnyi and add basic useful information for its chromosomal manipulations. © Central Fisheries Research Institute (CFRI) Trabzon, Turkey and Japan International Cooperation Agency (JICA).