Green sea turtles have a variety of parasites including barnacles, leeches, protozoans, cestodes, and nematodes. Endoparasites include nematodes, cestodes, and trematodes. As all other cestodes, they are hermaphrodite. Bertiella studeri is a species of "Bertiellia", a type of cestodes (tapeworms). The eel-tailed catfish is host for a number of intestinal parasites including cestodes and nematodes. The fine structure of tegument is essentially the same in both the cestodes and trematodes. Pilot whales are often infested with whale lice, cestodes, and nematodes. Like other cetaceans, they are hosts to parasitic worms such as cestodes and nematodes. Adult trematodes lay smaller numbers of eggs compared to cestodes or nematodes. As in all pseudophyllid cestodes, the genital pores open midventrally. The external surface of tegument is associated with unique defining structures in cestodes and trematodes. The killdeer is parasitized by acanthocephalans, cestodes, nematodes, and trematodes. Other worms namely Cestodes and trematodes occur in high numbers in the small intestines. The cobia is frequently parasitized by nematodes, trematodes, cestodes, copepods, and acanthocephalans. As other fish, groupers harbour parasites, including digeneans, nematodes, cestodes, monogeneans, isopods, and copepods.