Immune Competence of Wild and Hatchery Produced Macrobrachium rosenbergii Juvenile Exposed Experimentally to Vibrio spp

Abstract

This study was conducted to evaluate the immune competence of wild and hatchery produced Macrobrachium rosenbergii juvenile against Vibrio spp. It was conducted in plastic aquaria, providing same level of feeding under different treatments; Control wild (CW), Control hatchery (CH), Treatment wild (Tw), Treatment hatchery (Th). In the treatment groups, prawn juveniles were exposed to Vibrio spp. at a concentration of 2×10⁹ CFU/ml for seven days. In this study, Vibrio spp. was isolated from diseased giant freshwater prawn (M. rosenbergii). The results demonstrated that there was a significant difference (P<0.05) of mortality rate and THC between the control and the treatment groups of wild and hatchery prawns. There was no mortality in the control groups but 25% cumulative mortality rate (CMR) was found in both wild and hatchery treatment groups on day 5, and more than 50% CMR was on day 7 in both hatchery (65%) and wild (60%) groups. Total haemocyte count (THC) was found higher in treatment groups. Differential haemocyte count (DHC) data revealed that there was a significant difference (P<0.05) of large granular cell among the control groups of hatchery, treatment groups of hatchery and control groups of wild prawns but no significant difference (P<0.05) was found in treatment groups of wild prawns. On the other hand, significant difference was found among control group of hatchery, treatment group of hatchery and control group of wild for Semi granular haemocyte (SGH), Smaller granular haemocyte (SmGH) and Non granular haemocyte (NGH). However, this study pointed out that the prawns had dynamic response regarding THC and DHC, particularly in stress condition, of which association are to be determined through further research.