the evaluation of morphometric and meristic characters of barilus mesopotamicus (cypriniformes: cyprinidae) in seimareh, changoleh and siahgave rivers in ilam province.

study of fishes on aquatic ecosystems in many respects, including ecology, behavior, biology, conservation and management of water resources, exploitation of resources and training are important. so in the autumn 2011, the population structure of barilius mesopotamicus was studied. in this order, 69 samples of the mentioned fish from seimareh (34 samples), changoleh (20 samples) and siahgave (15 samples) rivers caught by electrofishing. twenty nine morphometric and seven meristic characters were analysed. morphological characteristics were standardized before statistical analysis to reduce the error of the allometric growth in morphological characteristics, nine factors were indicators of 73.73% characteristics diversity and in meristic characteristics two factors were indicators of 74.11% characteristics diversity between people of three populations. ten morphometric characters and four meristic characters had significantly showed the difference between populations. although, the principal component analysis (pca) and canonical variables analysis(cva) showed a relative overlap barilius mesopotamicus populations in seymareh and changoleh rivers, the siyah gav,s population located in a separate group. the results of this study showed that the morphometric and meristic characters could be separated the changoleh and seymareh rivers from siyah gav population very well.