Effectiveness comparison of 3 step injection LHRH-a2+PG with carp pituitary extract (2 step injection) in reproduction function of Barbus sharpeyi

    Barbus sharpeyi of Cyprinidae family is an endemic fish of the province Khuzestan. The Iranian Fisheries Organization (Shilat) produces millions fry (1–5 gr) to restock the horalazim and lagoon Shadgan population annually. The objective of this study was to assay the effectiveness of LHRH-α2 hormone combined with carp pituitary extract (3 steps injection) and carp pituitary extract (2 steps injection) on reproduction index in Barbus sharpeyi including: spawning success, latency period, weight of stripped egg  mass/weight of stripped egg mass remnant ovaries, and fertilization success. 200 fish were divided into 10 groups (180 fish treated with LHRH-α2 hormone combined with carp pituitary extract (3 steps injection) to different concentration  and 20 carp pituitary extract (2 steps injection) 4.5 mg kg^-1 b.w.). The results showed that the LHRH-α2 hormone combined with carp pituitary extract in three steps injection (Second treatment with 8µg/kg LHRH-α2 in step one, 0.5 mg/kg PG in step two and 3mg/kg PG in step three have excess steps than two step injection lead to higher Latency period, spawning success (72%) and weight of stripped egg mass/weight of stripped egg mass (8.67% average) and fertilization success (77.85%) and spawning rate in comparison with method 2 steps injection (P<0.05). Therefore, it can be concluded that LHRH-α2 hormone combined with carp pituitary extract (3 steps injection) is more effective than CPE (2 steps injection) for spawning induction in Barbus sharpeyi specially Second treatment have suitable concentration for artificial breeding.