NATURAL COMPONENTS TO COMBAT DISEASES.  PARTIM 1: MORE ROBUST SHRIMP BY STIMULATING PROTEIN CHAPERONES.

Optimizing the health status throughout the entire production cycle is an essential part in the holistic prevention of diseases for all aquaculture organisms. A promising way to improve the host's defense is by stimulating its heat shock proteins (HSP). HSP induction (HSPi) results in having more chaperones pro-actively produced in the animal so that they can better cope with anticipated future stressful conditions and infections (Fig.1). Here we present the results of a 3-year joint research project between INVE Aquaculture and Ghent University aimed at proving this concept.

First, a wide variety of compounds from plant origin were screened for their protective HSPi potential in a gnotobiotic Artemia model. Based on a database of efficacy and toxicity data for individual compounds in Artemia and shrimp, a mixture of natural HSPi components was selected to apply in the culture water of P. vannamei during the hatchery cycle. Temperature and osmotic stress tests demonstrated the improved robustness of the treated postlarvae, and their overall survival and biomass was 12-25% higher compared to the control standard hatchery protocol (tested in 175L, 3 m³ and 60m³ tanks, each replicated 3 times in time).

Subsequent evaluation of survival at PL14 after a simulated 12 hour transport at PL10 showed that those shrimp that were exposed to the HSPi mixture during the hatchery cycle and during transport were better adapted to overcome this stressful stage (Fig.2).

In conclusion, a synergistic mixture of natural HSPi components was formulated which enhances the intrinsic disease and stress resistance of shrimp postlarvae via a known pathway. For shrimp, investing in the quality of postlarvae by applying state-of-the-art hatchery management results in a significant return on investment for hatcheries and subsequent pond farming.