The exoskeleton of the
shrimps tends to be an effective physical barrier to pathogens trying to penetrate their
external surfaces. The Vibrio spp. are among the chitinoclastic bacteria and are capable to
enter through wounds in the exoskeleton or pores. The gills are covered by a thin exoskeleton
and appear susceptible to bacterial penetration. The mid-gut is not covered by an exoskeleton
and thus seems to be a site for penetration of pathogen