Shrimp growth functions and their economic implications

Obtaining a reliable growth function is an integral part of deriving the optimal harvesting strategy for any aquaculture operation. This paper examines the common functional forms of fitting growth equations for fish and shrimps. The following functional forms are considered: linear, polynomial, log reciprocal, Von Bertalanffy, Gompertz, logistic and exponential. Results of fitting these various functional forms with experimental data for Penaeus vannamei are compared and evaluated using standard statistical goodness-of-fit tests. The implications of these estimated growth functions in determining the optimal harvest schedule is compared and discussed. Results indicate that Gompertz and Von Bertalanffy functions are statistically the best fit to the experimental data and the harvesting schedule calculated based on these two functions well reflect the actual shrimp farm operation. Therefore, the Gompertz and Von Bertalanffy function may be the best functions describing shrimp biological growth and hence might be useful for economic evaluation.