The cellular community in the intestine of the shrimp Penaeus penicillatus and its culture environments

Abstract

In the present study, bacterial community diversities were investigated in the shrimp intestines, outside seawater and culture-associated environments using clone library analysis. Comparative analyses revealed that the bacterial community in the intestinal contents was most similar to that of the sediment. Bacteria in the phyla Proteobacteria and Firmicutes constituted the dominant components of the intestinal bacteria in the shrimp. The potential pathogens and probiotics were dominant members of the intestine in healthy or diseased shrimp. Intestinal bacterial communities in the healthy shrimp were composed of Bacillales, Rhodobacterales, Vibrionales, and Alteromonadales, whereas fewer bacterial groups were observed in the intestines of diseased shrimp, which were dominated by Vibrionales and Bacillales. Phylogenetic analysis revealed that nearly half of the sequences in the intestines of diseased shrimp were closely related to the potential pathogen Photobacterium damselae and Vibrio harveyi. Obvious differences in microbial diversity were also observed between outside seawater and culture-associated environments. Eukaryotes in the outside seawater were dominated by Skeletonema, Cyclotella, Thalassiosira, Guinardia, and Chaetoceros. The pond water showed less diversity in the eukaryotic community and was dominated by Skeletonema, Thalassiosira, Chaetoceros, and Oithona. The implications of the present study may be significant in the management of shrimp cultivation, as well as the detection of potential pathogens and the application of probiotics.