Metazoan parasites as indicators of movements of anadromous brook charr (Salvelinus fontinalis) to sea

1981 ◽  
Vol 59 (10) ◽  
pp. 1892-1896 ◽  
Author(s):  
Geoff A. Black
Keyword(s):  
Fresh Water ◽  
Salvelinus Fontinalis ◽  
Anisakis Simplex ◽  
Brook Charr ◽  
Metazoan Parasites ◽  
Diplostomum Spathaceum

Changes in the numbers of metazoan parasites of anadromous brook charr, Salvelinus fontinalis, during the summer 1980 were determined by examining 220 fish at different times and localities in the Moisie River, Quebec. The marine trematode Brachyphallus crenatus remained in brook charr during their movements into fresh water. Differences in the prevalence of this parasite between sampling localities in late July indicated that some charr which undergo smoltification do not go to sea although others do. Also, infection with B. crenatus enabled an estimate to be made of the percentage of charr that had been to sea entering a tributary in late August. Brook charr were also infected with Crepidostomum cooperi, Diplostomum spathaceum, Eubothrium salvelini, Proteocephalus sp., Metechinorhynchus lateralis, Echinorhynchus gadi complex, Cystidicoloides tenuissima, Hysterothylacium sp., Anisakis simplex, Acuarioidea: Seuratiinae gen. sp., Salmincola edwardsii, and glochidia larvae.

Potential use of certain parasites of brook charr (Salvelinus fontinalis) as biological indicators in the Tabusintac River, New Brunswick, Canada

1987 ◽  
Vol 65 (8) ◽  
pp. 1989-1995 ◽  
Author(s):  
Jack P. Frimeth
Keyword(s):  
New Brunswick ◽  
Fresh Water ◽  
Salvelinus Fontinalis ◽  
Black Spot ◽  
Biological Indicators ◽  
Gastrointestinal Parasites ◽  
Brook Charr ◽  
River Systems ◽  
Potential Use ◽  
Hysterothylacium Aduncum

A survey of 1146 nonanadromous and anadromous brook charr (Salvelinus fontinalis) from the Tabusintac River for parasites revealed 36 species of parasites, of which 18 were freshwater and 18 were marine. Most freshwater parasites were either too common or too rare in their occurrence to be of any value as biological indicators; however, Diplostomum sp. (metacercariae), Truttaedacnitis truttae, and Salmincola edwardsii were useful as indicators of foci of infection in fresh water. Decreases in prevalences of infection with marine gastrointestinal parasites in the estuary, especially Brachyphallus crenatus, Neoechinorhynchus sp., and larvae of Hysterothylacium aduncum, provided evidence for the approximate times of arrival of anadromous charr from fresh water. Marine gastrointestinal parasites were also useful as biological indicators of anadromous charr in fresh water, but these parasites were lost after varying times. High prevalences of infection with metacercariae of the marine digenean Cryptocotyle lingua resulted in a black spot condition that proved to be the best indicator of anadromous charr in fresh water. The distributions of Azygia longa, Echinorhynchus lateralis, and Zoogonus lasius from charr in the Tabusintac River as well as the nearby Miramichi and Burnt Church estuaries suggested that estuarine wanderings among adjacent river systems do occur. Tetraphyllidea gen. sp. plerocercoids from anadromous charr in the Tabusintac River were useful in identifying offshore movements of these charr into the Gulf of St. Lawrence.

Parasite-induced susceptibility to predation in diplostomiasis

Parasitology ◽  
1982 ◽  
Vol 85 (3) ◽  
pp. 495-501 ◽  
Author(s):  
P. Brassard ◽  
M. E. Rau ◽  
M. A. Curtis
Keyword(s):  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Marked Decrease ◽  
Infected Fish ◽  
Induced Susceptibility ◽  
Diplostomum Spathaceum

Guppies (Lebistes reticulatis) exposed to doses as low as 25 cercariae of Diplostomum spathaceum for 30 min were consistently and significantly more susceptible to predation by brook trout (Salvelinus fontinalis) than uninfected controls. The increase in susceptibility to predation was correlated with a marked decrease in the activity of infected fish.

Bénéfices à court terme des mouvements anadromes saisonniers pour une population d'omble de fontaine (Salvelinus fontinalis) du Nouveau Québec

1991 ◽  
Vol 48 (11) ◽  
pp. 2212-2222 ◽  
Author(s):  
Jean-François Doyon ◽  
Christiane Hudon ◽  
Roderick Morin ◽  
F. G. Whoriskey Jr.
Keyword(s):  
Water Level ◽  
Egg Size ◽  
Salvelinus Fontinalis ◽  
Condition Factor ◽  
Size At Maturity ◽  
Brook Charr ◽  
Tissue Water Content ◽  
Tissue Water ◽  
Single Population ◽  
Energetic Reserves

This study characterizes the seasonal anadromous movements of a brook charr population and compares its biological and energetic characteristics with charr spending summer in freshwaters. Downstream movements monitored at a counting fence over 3 yr were most intense in spring but occurred until fall and were positively correlated with rapid increases of water level. The timing of movements varied from year to year. Smaller charr were most subject to being swept downstream compared with freshwater residents, and most trout were concentrated near the mouth of the river. These patterns suggest that the downstream movements of charr in this system are passive. Upstream migrants had a higher condition factor and a lower tissue water content than freshwater residents, indicating that downstream movements result in a faster accumulation of energetic reserves during summer. However, the fortuitous character of anadromous migrations as well as the absence of differences in the biological characteristics (growth, size at maturity, fecundity, egg size) suggests that anadromous and resident fish belong to a single population whose yearly migrant component could be randomly determined.

Mechanisms responsible for the niche shift of brook charr, Salvelinus fontinalis Mitchill, when living sympatrically with creek chub, Semotilus atromaculatus Mitchill

1984 ◽  
Vol 62 (8) ◽  
pp. 1548-1555 ◽  
Author(s):  
Pierre Magnan ◽  
Gérard J. FitzGerald
Keyword(s):  
Laboratory Experiments ◽  
Salvelinus Fontinalis ◽  
Niche Shift ◽  
Intraspecific Aggression ◽  
Brook Charr ◽  
Semotilus Atromaculatus ◽  
High Level ◽  
Gill Raker ◽  
Creek Chub ◽  
Study Laboratory

When brook charr, Salvelinus fontinalis Mitchill, are in allopatry in oligotrophic Québec lakes, they feed largely on macrobenthic invertebrates. However, when brook charr cooccur with creek chub, Semotilus atromaculatus Mitchill, they feed largely on zooplankton. In the present study, laboratory experiments showed that creek chub were more effective than brook charr in searching for hidden, patchily distributed prey. The searching efficiency of an individual chub feeding in a group was improved through social facilitation. In contrast, the high level of intraspecific aggression observed in brook charr prevents the formation of such feeding groups. In the laboratory, brook charr were able to displace creek chub from the food source because of interspecific aggression. Data are presented showing that chub are morphologically better adapted than charr to feed on benthos (subterminal orientation of the mouth and protrusible premaxillae), while the charr are better adapted than chub to feed on zooplankton (gill raker structure). Differences in feeding behaviour, morphology, and relative abundance between these species appear to be important in the observed niche shift of brook charr in nature.

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