Comparison of morphological and reproductive indices of spring and autumn migratory populations of Mahi sefid (Rutilus kutum) to Anzali lagoon

The present study was conducted with the aim of comparing the morphological and reproductive indices of spring and autumn migratory Mahi sefid populations to Anzali lagoon. Therefore, 120 spring and autumn migratory Mahi sefid were caught at a station leading to Anzali lagoon. The results of the comparison of morphological characteristics showed that these characteristics were significantly higher in autumn broodstocks than spring broodstocks. Based on the analyzing into main factors, total length, fork length, standard length and body weight traits expressed 73.33% of the diversity of morphological characteristics between spring and autumn populations. Comparison of reproductive characteristics did not show any significant difference in absolute fecundity between spring and autumn populations (P>0.05). The average relative fecundity, number of eggs and sperm volume of the spring broodstocks were significantly higher than the autumn breed (P<0.05). The fertilization percentage after 24 and 48 hours in the autumn form were significantly higher than the spring form (P<0.05). Therefore, the broodstocks of the autumn form were higher in morphological characteristics and fertilization percentage, and the broodstocks of the spring form were higher in relative fecundity, number of eggs and sperm volume.