RELATIONSHIP BETWEEN BP (BACULOVIRUS-PENAEI) AND ENERGY RESERVES IN LARVAL AND POSTLARVAL PACIFIC WHITE SHRIMP PENAEUS-VANNAMEI

The relationship between energy reserves of the penaeid shrimp Penaeus vannamei and Baculovirus penaei, or BP, were investigated in a series of experiments using mysis stage or early postlarval shrimp. Pre-expo sure and post-exposure levels of protein and triacylgycerol (TAG) were determined. The effect of pre-exposure protein and TAG levels on susc eptibility to BP infections was also investigated by starving a group of shrimp immediately prior to BP exposure. There was no consistent re lationship between either pre-exposure or post-exposure protein levels and the percent of shrimp developing patent BP infections. There was, however, a significant positive correlation between TAG levels immedi ately prior to viral exposure and prevalence of infection 72 h later. Experimental reduction of TAG reserves prior to BP exposure delayed th e development of a patent infection. In some, but not all, experiments there was a significant reduction in TAG levels of infected compared with uninfected shrimp 72 h post-exposure. The effect of patent BP inf ections on host TAG levels was subordinate to fluctuations in TAG cont ent associated with the ontogeny of the hepatopancreas. Results of thi s study support histological observations that shrimp lipid levels can be altered by baculovirus infections. Furthermore, high levels of ene rgy reserves in the form of TAG are associated with increased suscepti bility to BP infection in larval and postlarval shrimp.