The GSI of female C. arel, gradually increased from October to January, ranging from 0.8 ± 0.13 to 3.53 ± 0.26 (mean ± standard error, SE). The highest value (6.01 ± 0.52) was found in February, followed by steep decrease until June (0.7 ± 0.07). Between June and September, the GSI was relatively low from 0.7 ± 0.07 to 0.63 ± 0.02, that there seems to be a resting period. In male, the GSI were higher between January and June with the highest mean in May (0.10±0.007) and decreased between October and December 2009 and between July and September 2010, therefore this pattern of GSI in males was consistent with