تعيين رابطه سن مولدين نر با عوامل كارايي تكثير مصنوعي در ماهي آزاد درياي خزر ( salmo trutta caspios , kessler 1877)

Determination of Relationship between age with efficiency factors Artificial Propagation in Caspian salmon (Salmo trutta caspious, Kessler 1877) Spawners males

Caspian salmon {Salmo trutta caspious, Kessler 1877) is one of the economically valuable fishes in the Caspian Sea. One of the main problems in itʹs culture is artificial propagation and production of larva. In among of those, male broods have significant role in propagation process. For this target in the propagation season at 2009, is studied the effect of reproductive performance of male broods on Artificial Propagation efficiency in Caspian salmon. For this study, 3 groups of male broods (4, 5 and 6 years old) are fertilized with female fish individually. The results showed that, 6 years old male have maximum rate in mean of body weight before stripping (1766.67 ± 152.75 gr), body weight after stripping (1735.0 ± 152.23gr), total length (56.33 ± 2.08 cm) and milt volume (31.83 ± 6.22 ml), it wasnʹt significant difference spermatocrit percentage and concentration of mail between these male broods (P> 0/05). The present study showed that the produced eggs from fertilization of 4 years old males milt and female mixed ova have maximum average of rate in fertilization percentage (98.5 %), survival rate until eyeing percentage (91/17%), hatching percentage (94/5%) and survival rate until absorption of yolk sack stage (97/16%). So 4 years old male brood stocks are the best choice for economical and environmental in artificial propagation.