Karyological study on bighead goby (Neogobius kessleri) from southern part of the Caspian Sea.

Karyological characteristics of bighead go by (Neogobius kessleri) in the Caspian Sea were studied by examining 30 metaphase chromosome spreads from the kidney tissue of 10 specimens. The chromosome number of this species was found 2n=46 and the arm number as NF=46. The prepared karyotype of this species consisted of 23 pairs aero-telocentric (a-t) chromosomes. The chromosomal formula can be stated as 2n=46 (a-t). Karyological parameters showed that relative length was between 2.34-7.04 and length variation range of chromosomes was between 1.67-5.01 and total length was 71.16 (mu)m. It was found that the best chromosomal spread quality were obtained from intraperitonial injection of 40 (mu)g/g colchicine for 5 hours, hypotonization of samples in %1 sodium tri-citrate solution in 4°C and preparation of spreads on cooled slide with flame technique.