Azam Mansoori - Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran
Mehregan Ebrahimi - Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran- School of Biological Sciences, Flinders University, Adelaide, SA, Australia
Ali Gholamhosseini - Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran
Hamdi Reza Esmaeili - Department of Biology, College of Sciences, Shiraz University, Shiraz, Iran

The karyological and cytological characteristics of an endemic cyprinodont fish of Iran, Aphanius shirini have been investigated for the first time by examining metaphase chromosomes spreads obtained from gill epithelial and kidney cells. The diploid chromosome number of this species is 48. The karyotype consisted of one submetacentric and 23 subtelocentric pairs of chromosomes (2Sm + 46St). The chromosome arm number (NF) is 50. Sex chromosomes were cytologically indistinguishable in this tooth-carp. Based on the present and previous reported diploid chromosome number for other cyprinodont species, it can be suggested that the diploid chromosome number of 2n = 48 is the modal number of the cyprinodont fish.

Cyprinodontiformes, Chromosome, Cytogenetical analysis, Idiogram