1 research outputs found
The study of artificial propagation efficiency and fingerlings production of Coregonus lavaretus
In order to study of the artificial propagation efficiency in white fish (Coregonus
lavaretus) and its fingerlings producing in IRAN, a 9 mounts study project was been
done which during it, the characteristics of the matures and brood stocks fishes, the
condition of their natural and artificial propagation, and the characteristics of produced
frys, were been studied. Throughout the total 82 pieces caught fishes during September
til February 2003, 10 pieces of them were the female brood stocks which during the
catch time did not have spouse. The study of these fishes showed that there was no
significant correlation between their weight and their length. The most and the least
absolute fecundity of these brood stocks were 19120 and 11496 respectively. The
artificial propagation was been done by 5 males and 4 females broods took which
57602 ova, with 89/2% fertilization rate, earned from them. The incubation period
prolonged 55 days in 8°c. At the end of the incubation, 23913 larvae released. So the
artificial propagation efficiency was calculated 41/51% in this study. Yolk sack
absorption prolonged 4 days. 3 different food treatment were considered for fry
breeding which contain of Brachiouns plicatilis as live food, salmon starter food as
commercial food, and the mixed of equal amounts of live and commercial foods as third
treatment. For each treatment, 3 repeat has been considered. Breeding duration
prolonged 13 weeks throughout this period, different characteristics of fry were been
studied weekly. The breeding results showed that there was very significant correlation
between the weight and the length of frys. However the live food provided better results
in growth and survival rate of frys during breeding initial 6 weeks.
More ever, commercial food, in some characteristics, provided more acceptable results
in comparing the live food after sixth week. The results of this study project showed
that the artificial propagation in whitefish is possible in IRAN and the producing of its
frys in order to restocking or introducing this species to the other Iranian suitable water
resources is executable. Based on the earned information from this study, the suitable
time for natural spawning of whitefish in IRAN (Amirkabir dam lake) determined
between 10th January til 20th February