Spawning cycle, GSI index and length maturity of Deep flounder in northwest of Persian Gulf, Iran

During this study from December 2009 to November 2011, 363 Deep flounder fish were caught and their weights and lengths were measured. Total number of caught fishes included: 18 males, 200 females and 155 immature fishes. The mean, maximum and minimum total lengths were 264 ± 57, 415, and 115 mm, respectively. The mean, maximum and minimum total weights for this species were 238 ± 150, 827, and 14 g, respectively. The length-weight relationships were calculated as W = 0.000007FL3.09 (n = 200, R2 = 0.96) for females, W = 0.00002FL2.90 (n = 18, R2 = 0.94) for males and W = 0.000009FL3.04 (n = 363, R2 = 0.96) for total fishes verifying calculated b with 3, using Students t-test. There was no significant difference between calculated b and 3, and growth pattern was isometric. The mean values of condition factor (K), hepatosomatic index (HIS) and gonadosomatic index (GSI) were 1.25 ± 0.43, 1.13 ± 0.04, and 1.14 ± 0.97 for total fishes, respectively. The highest values of K, HIS, and GSI were observed in February, August and April; whereas the lowest values were observed in January, December and January. Mean GSI value indicated that spawning time were occurred during April to May. Using one-way ANOVA Test, the relationship between GSI index and temperature and salinity was significant. The mean size at first sexual maturity (Lm) was 237 mm for total fishes.