Morphometric relationship of total weight and total length and condition factor of cultured female whiteleg shrimp, Penaeus vannamei, under semi-intensive condition

Western whiteleg shrimp (Penaeus vannamei) is the most important marine farmed shrimp species in Iran. Because this species is non-native shrimp, provision of broodstocks totally rely on imports from the main producing countries. The culture of broodstocks under Iran's condition is considered as one of the main aspects of developing this industry. So, the morphometric relationship between total length and total body weight and also condition factor of cultured female whiteleg shrimp were analyzed during grow out phase, starting from 70 to 290 days of semi-intensive culture in earthen ponds. Regression lines between total length and total body weight were significantly different among seasons. Shrimps demonstrated the same body weight increase values in autumn and spring. So, the same regression line was considered as BW=0.0049TL3.2096 for these two seasons. This line for winter (BW=0.11TL1.9668) was significantly different from the both previous mentioned seasons. On the other hand, the female shrimps showed significantly higher condition factor in spring is compared to autumn, but not to winter. Considering the relationship between total length and total body weight is suggested to simplify the management of the grow out phase of shrimp and estimation of the body weight and condition factor of individuals by means of total length could be easily managed.