Life cycle of Truttaedacnitis stelmioides (Vessichelli, 1910) (Nematoda: Cucullanidae) in American brook lamprey (Lampetra lamottenii)

Abstract

Field data from two populations of Lampetra lamottenii (Lesueur, 1827) in Ontario, combined with informattion from experimental studies, have provided the following explanation of the transmission of Truttaedacnitis stelmioides (Vessichelli, 1910). Eggs hatch on the stream bed in spring and early summer. Newly hatched larvae are ingested by filter-feeding ammocoetes and remain in the intestine throughout the summer. After developing to the third stage, larvae migrate via the bile duct to cystic ducts of the liver where they remain in a state of arrested development for up to 4 years. During transformation of the host, third-stage larvae apparently moult at least once in the liver, reenter the intestine, and develop to maturity in transformers and adult lampreys. Eggs are released into the lamprey intestine and eventually passed from the anus. Transmission occurs mainly in early summer. Truttaedacnitis stelmioides never becomes encapsulated in the gut wall of L. lamottenii although it may in other lamprey species. Lampetra lamottenii may be the most suitable host among the lampreys. The biology of the parasite is closely linked to the metamorphosis and maturation of the lamprey. Other cucullanids may have a similar relationship with their hosts. Possibly the cucullanids are basically heteroxenous in that they use the immature stage of the host (e.g. the ammocoete) as an intermediate host.

Guide to the Parasites of Fishes of Canada Part V: Nematoda

“…Coregonus artedi (7,21,23,29); Coregonus clupeaformis (1,7,13,19,29) 4, 5, 7, 8, 9, 11, 12, 14, 16, 17, Pybus et al 1978a) Preamble: Choudhury & Dick (1996b) analysed phylogenetically the genus Truttaedacnitis referring inter alia to the morphology and arrangement of the various cephalic plates. Because the homology of some of the cephalic plates could not be determined, these workers did not use the total number of plates in their analysis.…”

“…Larvae: Pybus et al (1978b) and Anderson (1996) discussed the transmission of T. pybusae, including the morphometry of larvae in lamprey ammocoetes and "transformers". The biology of the nematode appears to be closely linked to the metamorphosis and maturation of lampreys.…”

“…The biology of the nematode appears to be closely linked to the metamorphosis and maturation of lampreys. Sites: gills, gonads, intestinal lumen, kidney, liver, mesenteries Host: Lethenteron appendix Distribution: Ontario Records: Pybus et al 1978a;Pybus et al 1978b;Anderson 1996 Truttaedacnitis sphaerocephala (Rudolphi, 1809) Petter, 1974 Synonym: Bulbodacnitis sphaerocephala (Rudolphi, 1809) Maggenti, 1971 Description (after Dick 1996b, andMoravec 2013). With characteristics of the genus.…”

Morphology of the bile ducts of the brook lamprey, Lampetra lamottenii (Le Sueur) before and during infection with the nematode, Truttaedacnitis stelmioides (Vessichelli, 1910) (Nematoda: Cucullanidae)

“…It may be that T. stelmioides, as is the case with the other biliary parasites, acts as an irritant to cause elaboration and secretion of mucus by the biliary epithelial cells. The irritation may be chemical (i.e., parasite metabolic products) but not likely mechanical, since T. stelmioides does not migrate once it is in the biliary tree (Pybus et al, 1978). In mammals, the elaboration and release of mucinous material by host epithelial cells are a means of protection from highly concentrated bile which is irritative and injurious to bile duct cells (McMinn and Kugler, 1961;Yamada, 1969).…”

“…sinensis (Hou, 1955) and F . hepatica (Ong, 19851, since the nematode is in an arrested state of development (Pybus et al, 1978). Ultimately, the elaboration of excess mucus may contribute to obstruction (Hou, 1955;Gibson and Sun, 1971), as suggested by the occluded appearance of the bile ducts.…”