Study and comparison of some characters of reproductive biology of two relative species : Barbus barbulus, Barbus pectoralis

This study was carried out from December 2007 to November 2008 in Karoon River in Khuzestan province. From the total number of 578 specimen 53, 58 were females and males respectively, and 125 specimen were immature (Barbus barbulus) besides 51,62 were males and females, and 229 were immature (Barbus pectoralis). Samples were caught by cast nets and fixed gill nets. Total length, age, sex, and maturity of these fishes were determined. Lenght range of B.pectoralis was 945-200 mm and their weight ranged was 11170-52gr. B.barbulus range was 885-230 in length and 8460-99 gr in weight. Spawning season of B.pectoralis is determined by using the GSI obtained ,and the analasys of information shows it is the February (Bahman) and for B.barbulus is in March (Esfand) in Shushtar staition. LM50 of male and female of B.barbulus is determined 45-50cm, 50-55 cm respectively. This was identified for B.pectoralis male and female 35-40 cm and 50-55 cm respectively. First maturity of male and female of B.pectoralis observed at 35-40 cm and 40-45 respectively. This was identified for B.barbulus male and female 30-35 cm, 40-45 cm respectively . Maturity age of male and female of B.pectoralis is determined 3+, 4- respectively. This was identified for male and female of B.barbulus 2+, 3- respectively. Sex ratio of B.pectoralis and B.barbulus is determined using chi square test,those are identified (male/female) as 1/1:1 and 1:1 respectively. Conclusively these species were separated form each other previously so they are independent now.