Parasites of capelin (Mallotus villosus) in the St. Lawrence estuary and gulf

Abstract

A survey of the parasites of capelin (Mallotus villosus) caught on the spawning grounds at five localities in the estuary of the St. Lawrence River and the Gulf of St. Lawrence, Canada, was conducted in 1994. From examination of 125 fish, a total of 21 parasite taxa was identified (2 Protista, 3 Monogenea, 4 Digenea, 4 Cestoda, 7 Nematoda, and 1 Acanthocephala). Seven new host records are reported for this fish (Trichodina sp., Brachyphallus crenatus, Bothrimonus sturionis, Ascarophis sp., Pseudoterranova decipiens larva, Spirurida gen.sp. larva, and Echinorhynchus laurentianus). The parasite fauna of capelin is comparatively depauperate. It is characterized by the relative abundance of a few species showing a high level of host specificity (Microsporidium sp., Trichodina sp., Gyrodactyloides andriaschewi, G. petruschewskii, Laminiscus gussevi, and Eubothrium parvum) that mature on or in capelin, several ubiquitous adult digeneans (e.g., B. crenatus, Derogenes various, Hemiurus levinseni, and Lecithaster gibbosus), and a number of species that use capelin as intermediate or transport hosts (e.g., Scolex pleuronectis plerocercoid, Anisakis simplex larva, Contracaecinea gen.sp. larva, and Hysterothylacium aduncum larva).

Parasites as biological tags of marine, freshwater and anadromous fishes in North America from the tropics to the Arctic

“…Among the most popular techniques used is stepwise parametric or non-parametric discriminate function analysis (DFA), which measures how accurately a given individual fish fits into one sample vs another (e.g. Arthur and Albert, 1993, 1996; Boje et al 1997; Blaylock et al 2003; McClelland et al 2005; Melendy et al 2005; McClelland and Melendy, 2007, 2011). The coherence of different samples of fish from across a region can then be assessed using only parasites that significantly contribute to assigning fish to specific samples or areas.…”

“…2), for Greenland halibut Arthur and Albert (1993) found only five of 46 parasite taxa (see Arthur and Albert, 1994) to be discriminatory, while Boje et al (1997) selected three of 21 taxa. For capelin, Arthur and Albert (1996) selected three of 21 taxa (see Arthur et al 1995). McClelland and Melendy (2007, 2011) found two of 11 and four of nine parasites enumerated to be useful in delineating stocks of American plaice and Atlantic cod, respectively, in the Gulf of St Lawrence.…”

Distribution and abundance of sealworm (<i>Pseudoterranova decipiens</i>) and other anisakid nematodes in fish and seals in the Gulf of St. Lawrence: potential importance of climatic conditions

“…from fish are extremely difficult to differentiate (McClelland et al 1985, Brattey 1995. In fish surveys the two are often combined and referred to as Contracaecinea (Arthur and Albert 1993, Arthur et al 1995, Boily and Marcogliese 1995. Levels are normally higher in Atlantic cod (McClelland et al 1983, McClelland et al 1985, Boily and Marcogliese 1995 and grey seals (Marcogliese et al 1996) from the northern Gulf compared to those from the southern Gulf.…”

“…4) (McClelland et al 1983, Boily andMarcogliese 1995). The most heavily infected fish in the Gulf in 1990-94 included Atlantic cod, longhorn and shorthorn sculpin, Greenland halibut (Reinhardtius hippoglossoides) and capelin (Mallotus villosus) (Arthur and Albert 1993, Arthur et al 1995, Boily and Marcogliese 1995, Marcogliese 1995.…”

Occurrence of anisakid nematodes in Atlantic cod (Gadus morhua) and Greenland cod (Gadus ogac), West Greenland

“…However, cod usually express an ontogenetic shift in feeding behaviour from small prey items such as crustaceans to particularly capelin (Nielsen andAndersen 2001, Link andGarrison 2002, present study). Because capelin is an important paratenic or intermediate host for several species of anisakid nematodes (Arthur et al 1995, Hays et al 1998, serving to accumulate their infective larval stages, we therefore specifically investigate the hypothesis that increasing parasitism with host size/age is not solely a matter of time but also partly due to changed feeding habits towards more infected prey (Dogiel 1958). We also specifically address the likely hypothesis that increasing nematode infections affect the host negatively.…”