Population dynamics of the Caspian roach (Rutilus caspicus) in the South East Caspian Sea

Abstract

Introduction: This study was carried out to investigate population dynamic of Caspian roach (R. caspicus) on the south east Caspian Sea in 2018 (In the 6 months of the catch season).
Materials & Methods: A total of 215 samples were collected using beach siene (Total length with 0.01 accuracy and total weight with accuracy of 0.001 were measured).
Result: The length of samples ranges from 16.74 to 30.03 cm and weighing from 52 to 346 gr. The age of the specimens was ranges from 3+ to 7+. Length-weight relationship was W=0.009L3.09, indicating positive allometric growth for population. After fitting the regression using least square method, the relationship was W=0.009L3.42. The Von Bertalanfy growth equation as, Lt=37.1033(1-EXP (-0.19(t+0.40)). Natural mortality using Pauly's experimental equation calculated as 0.445. The highest condition factor and growth rate was 0.42 and 0.44 respectively, for population in the south east Caspian Sea.
Conclusion: Overall, the Caspian roach stocks in the southeastern part of the Caspian Sea appear to be in serious danger and require effective management strategies to maintain their reserves.