This study examined the ultrastructure, parasitology, histopathology and effects of captivity on the Hawaiian Deep-Sea Caridean shrimp H. Leavigatus. Shrimp trapped at 2,000 feet were found to have a significant difference in muscle organization when compared to shallow water species (Penaeus vamamei). H. leavigatus also harbored several unusual epicuticular intracellular microorganisms and a single-celled organism in the gill lamellae. Diagnostic histopathology carried out on shrimp maintained in captivity after trapping indicate that death may be a function of severity and extent of acute trauma to the gills.