The ectoparasites that infest two hosts, mangrove crabs (Scylla serrata) and white shrimps (Litopenaeus vannamei) of the subphylum crustacea were studied. The study revealed that Octolasmis sp., Zoothamnium sp. and Epistylis sp. were found to infest mangrove crabs, while Zoothamnium sp. and Epistylis sp. were found parasitizing the white shrimp (Litopenaeus vannamei). The most common organ attacked by the ectoparasites was the gills. Stagnant water with limited or no flow of water in the ponds was an important factor that supported the infestation of parasites.