Changes of gonadosomatic index of pike (Esox lucius Linnaeus, 1758) during spawning season

The present study was carried out to evaluate the effect of spawning ongonadosomatic index (GSI) of pike (Esox Lucius) during spawning season. For thispurpose 108 pike specimens were caught (54 males and 54 female) in December 2012(pre-spawning), January (final maturity) and February 2013 (post-spawning) usinggill net from Anzali Wetland. Body and gonad weights were measured to the nearest0.1 and 0.001 gram respectively. Comparison of mean of GSI among three spawningstages, was performed using Tukey post-hoc test at a significance level of 95% inSPSS 16.0. The results of ANOVA showed a significant differences in GSI valuesbetween oocytes in final maturation with pre and post- spawning stages in females(P<0.05). In male spawners however such differences was observed only betweenfish in post-spawning stage with two other stages examined in this study (P<0.05).The obtained result showed a reduction in GSI index when fish enter the restingstages following spawning.

کلیدواژه ها:

Reproduction ، GSI ، Pike (Esox lucius) ، Anzali Wetland