A study on morphological variation of Chub, Leuciscus orientalis, (Nordmann, 1840) in the southern Caspian Sea basin

In the present study the morphologic traits of Leuciscus orientalis (Nordmann, 1840) populations were examined in the Doogh River, Siahroud River and the Sefidroud River in the Southern Caspian Sea basin. A total of 190 fish specimens were collected and 25 morphometrics, 5 proportional morphometrics and 9 meristic characters were recorded. Existence of sexual dimorphism was confirmed in all populations by t test analysis on morphometric features. Pupil diameter, postdorsal distance, length of anal fin base, interorbital distance and head width were significant different between male and female specimens (p<0.05). Despite of similar meristic characters among populations, Doogh population has more connection to Siahroud population based on taxonomic distance of morphometric traits rather than Sefidroud population. PCA revealed that first and second componants cause 69.77% of total variance of differences. In order to show clear relation of populations CVA/MANOVA analysis has been applied. The results showed that all populations separate significantly (Wilk̍s lambda= 0.052, p<0.05), first and second canonical includes 66.8% of total variance. Coudal peduncle width, pectoral fin base and eye diameter were loaded on first canonical and inter-orbital distance, pupil diameter and length of anal fine base were loade on second canonical.