Triaenophorus nodulosus, the pike tapeworm, is a species of parasitic cestode (tapeworm) in the family Triaenophoridae.Triaenophorus nodulosus (Pallas, 1781) Rudolphi, 1793. gbif.org. Accessed 2023-06-17. It is known to infect the northern pike, as well as other piscivorous fish, being found in the intestine of its host.Chubb, J. C. (1963). Seasonal occurrence and maturation of Triaenophorus nodulosus (Pallas, 1781) (Cestoda: Pseudophyllidea) in the Pike Esox lucius L. of Llyn Tegid. Parasitology, 53(3-4), 419–433. It has been found in North America, Europe and England.
Description Adult specimens of Triaenophorus nodulosus have been seen to range from long. When having a developed egg in the uterus, their maximum width is . There are four hooks on the scolex, with an angled plate about wide and deep. Its cirrus sac is long.Miller, R. B. (1952). A review of the Triaenophorus problem in Canadian Lakes. Bull. Fish. Res. Bd. Canad. 95, 42P.
The eggs of the species are white, but turn brown around 45 minutes after being placed in water. They are ovoid; they are about long and in diameter. Oncospheres can be made out inside ripe eggs. Coracidia are around the same size of the egg, and are ovoid as well. They are about long and wide.Miller, R. B. (19436). Studies on cestodes of the genus Triaenophorus from fish of Lesser Slave Lake, Alberta. II. The eggs, coracidia and life in the first intermediate host of Triaenophorus crassus Forel and T. nodulosus (Pallas). Canad. J. Res. D, 21, 284-91.
Hosts Triaenophorus nodulosus has been found in a variety of fish, such as the northern pike, the coho salmon, the sockeye salmon,WoRMS (2023). Triaenophorus nodulosus (Pallas, 1781) Rudolphi, 1793. Accessed 2023-06-17. the Great Lakes muskellunge,Choquette, L. P. E. (1951). Parasites of freshwater fish. V. Parasitic helminths of the muskallunge, Esox m. masquinongy Mitchill, in the St Lawrence watershed. Canad. J. Zool. 29, 290-5. and the walleye,Miller, R. B. (1943). Studies on cestodes of the genus Triaenophorus from fish of Lesser Slave Lake, Alberta: I. Introduction and the life of Triaenophorus crassus Forel and T. nodulosus (Pallas) in the definitive host, Esox lucius. Canadian Journal of Research, 21d(6), 160–170. as well as other fish from the United States and Canada. It uses piscivorous fish as definitive hosts, and uses smaller, preyed-upon fish or other marine organisms, such as copepods in the genus Cyclops,Copland, W. O. (1956). Notes on the food and parasites of pike (Esox lucius) in Loch Lomond. Qlasg. Nat. 17, 230-5. Accessed via Biodiversity Heritage Library. as intermediate hosts. When infecting its hosts, it embeds itself in the intestines or viscera.
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