Length-Weight Relationship of Dasyatis kuhlii in Kurunahar Waters, Sri Lanka

Abstract

The present investigation was carried out to identify the length-weight relationship and growth pattern of Dasyatis kuhlii from the Kurunahar waters which is the part of the Jaffna estuary. D. kuhlii is commonly known as blue spotted stingray. Random samples were collected in every month, from January to December 2012 from Kurunahar fish landing centre, Northern of Sri Lanka.month, A total of 285 specimens were analyzed. Covariance analysis for length-weight relationships of male and female D.kuhlii reveals that there was a significant relationship between logistic values of length and weight of male and female (P<0.000), (P<0.000), respectively. The estimates of the regression parameters and equation for male and female of D.kuhlii were TW =0.00229*DW 3084 (N=129, R2= 0.946] and TW= 0.0344 *DW2967 (N=156, R2= 0.972), respectively. The exponent value, b=3.084 for males and b= 2.967 for females, different from 3. Males expressed positive allometric growth whereas females reflect a negative allometric growth. The results will help to establish the yield and convert variables as it is often required during field measurement.