نوع مقاله : مقاله پژوهشی
گروه شیلات، دانشکده منابع طبیعی، دانشگاه گیلان، صومعه سرا، ایران.
عنوان مقاله [English]
In this study, 17 females (90.1±4.4 g) and 14 males (74.8±2.1 g) broodstock of Razi Siah Mahi (Capoeta razii) were captured by cast net from Shalmanroud River in Guilan Province during the reproduction season and kept in controlled condition. After the adaptation to hatchery condition, 0.5 mg Ovaprim (20 µg sGnRH analogue and 10 mg domperidone per ml) per kg body weight (BW) was injected in the basal pectoral fin region to 10 females and 7 males at one stage. Moreover, other 7 females and 7 males were not injected (as control). All fish were checked 6 h interval and female fish showed positive response to hormone induction 25.9±0.8 h following the injection; while no spawning was observed in control group. All males showed positive response to hormone-therapy and spermiation was observed after 24.8±0.7 h, while no spermiation was observed in control group. After spawning and spermiation, spermatological parameters and reproductive performance were evaluated. The average of obtained oocyte weight and the number of oocytes were determined as 4.2±0.2 g and 445.0±23.7 oocyte g-1, respectively. Absolute and relative fecundities were calculated as 1869.7±183.7 and 22.4±3.9 oocyte per g BW, respectively. The examination of spermatological parameters showed motility time 72.0±12.0 s, motility rate 80.7±3.2%, sperm density 91.4±1.4% and spermatocrit 26.3±5.30%. After insemination, fertilization rate, hatching rate and the number of larvae per spawner were recorded as 86.5±1.8%, 88.5±1.8%, and 1662.8±173.6 larva, respectively. The results of this study showed that Ovaprim successfully induced maturation in female and male Capoeta razii at a single dose in captivity and it can be used in hatcheries for stock rehabilitation and mass production of fry.