Description: "Possess an anterior extremity which is bilaterally symmetrical and lack lateral, external labial papillae. The caudal papillae are always ventral or ventro-lateral in position. There is no pre-anal sucker. There are longitudinal bands sustaining the buccal valves separated into ventral and dorsal groups. Parasites of fishes and amphibians typically found in anterior part of the gut or in tissues" (Anderson et al., 2009).
Life Cycle: “Almost universally, camallanids have a two-host life cycle, with sexual reproduction as adults in vertebrates, free-living larvae infecting copepods and vertebrates becoming infected by ingensting infected copepods. However, it appears that direct transmission (i.e., vertebrate hosts are infected by ingesting free-living larvae) may be possible (Levsen & Jakobsen 2002). Additionally, if an infected copepod is eaten by a host in which the worm cannot develop, that host may become a paratenic host, i.e., the larva is not killed and does not develop further but remains infective if the new paratenic host is eaten by a host in which the worm can develop to sexual maturity” (Schmidt-Rhaesa, 2014).
Sources: Schmidt-Rhaesa, A. (ed.). 2014. Handbook of Zoology. Gastrotricha, Cycloneuralia and Gnathifera. Vol. 2: Nematoda, p. 638.
Anderson, R.C., Chabaud, A.G., and Willmott, S. 2009. Keys to the Nematode Parasites of Vertebrates, Archival Volume, p. 311.