Filicollis anatis is an endoparasite in the Polymorphidae family of thorny-headed worms.[1] Adults have been found to occur in waterbirds such as ducks,[2] where they cause a condition known as filicollosis.[3] Larval stages occur in invertebrate hosts such as crayfish.[4]
A study in the Chernihiv region of Ukraine found that F. anatis infected ducks throughout their grazing period, but not in the winter; it also found that the parasite's eggs could remain viable throughout the winter when buried in mud under natural conditions.[5]
Acanthocephalans such as F. anatis form capsules in their intermediate arthropod hosts to protect the developing larvae from the host immune system. F. anatis forms its capsules primarily by secreting material during the initial (acanthellar) stage after infecting the intermediate host.[6]
^Soliman, K. N. (1955). "Observations on some helminth parasites from ducks in southern England". Journal of Helminthology. 29 (1–2): 17–26. doi:10.1017/s0022149x00024172.
^Hofmann, U.; Grafner, G.; Tscherner, W. (1989). "Epizootiology, clinical course, and diagnosis of acanthocephalosis (filicollosis) in Common Duck". Monatshefte für Veterinaermedizin. 44 (16): 576–578.
^Nickol, B. B.; Heard, R. W.; Smith, N. F. (2002). "Acanthocephalans from crabs in the southeastern US, with the first intermediate hosts known for Arhythmorhynchus frassoni and Hexaglandula corynosoma". Journal of Parasitology. 88 (1): 79–83. doi:10.1645/0022-3395(2002)088[0079:afcits]2.0.co;2. PMID12053984.
^Nikishin, V. P. (1992). "Formation of the Capsule around Filicollis anatis (Acanthocephala) in Its Intermediate Host". The Journal of Parasitology. 78 (1): 127–137. JSTOR3283699.
