Capelin (Mallotus villosus) and herring (Clupea harengus) as paratenic hosts of Anisakis simplex, a parasite of beluga (Delphinapterus leucas) in the St. Lawrence estuary

1998 ◽  
Vol 76 (8) ◽  
pp. 1411-1417 ◽  
Author(s):  
Réjean Hays ◽  
Lena N Measures ◽  
Jean Huot
Keyword(s):  
Anisakis Simplex ◽  
Clupea Harengus ◽  
Delphinapterus Leucas ◽  
Intermediate Hosts ◽  
Mallotus Villosus ◽  
Lawrence Estuary ◽  
Third Stage ◽  
Capelin Mallotus Villosus ◽  
Paratenic Hosts ◽  
St Lawrence Estuary

Capelin (Mallotus villosus) (N = 760) and herring (Clupea harengus) (N = 165) were collected in the St. Lawrence estuary during the summer of 1994 and 1995 to examine the importance of pelagic fish in transmission of Anisakis simplex to cetaceans. Larval A. simplex were removed from fish by means of a pepsin-digest solution or by dissection. Prevalence of A. simplex in dissected capelin was 5%, with a mean intensity of 1.2. Prevalences of A. simplex in herring were 95 and 99%, with mean intensities of 6.2 and 6.8 for pepsin digestion and dissection, respectively. Third-stage larval A. simplex found in capelin and herring were compared with third-stage larvae found in euphausiids and belugas (Delphinapterus leucas) from the St. Lawrence estuary and no differences in size or morphology of larvae from these four hosts were observed. Euphausiids, which harboured moulting second-stage and third-stage larvae, are intermediate hosts of A. simplex. As there was no apparent development of larvae in herring or capelin, these fish are considered to be paratenic hosts of A. simplex in the St. Lawrence estuary.

Euphausiids as intermediate hosts of Anisakis simplex in the St. Lawrence estuary

1998 ◽  
Vol 76 (7) ◽  
pp. 1226-1235 ◽  
Author(s):  
Réjean Hays ◽  
Lena N Measures ◽  
Jean Huot
Keyword(s):  
Anisakis Simplex ◽  
Intermediate Hosts ◽  
Lawrence Estuary ◽  
Second Stage ◽  
The Third ◽  
Third Stage ◽  
Important Intermediate ◽  
Meganyctiphanes Norvegica ◽  
Saguenay River ◽  
St Lawrence Estuary

To determine abundance of larval Anisakis simplex in euphausiids of the St. Lawrence estuary, Meganyctiphanes norvegica and Thysanoessa raschii were collected at seven sites from the mouth of the Saguenay River to Baie des Outardes. Larvae were removed from euphausiids by means of a modified Baermann apparatus filled with a pepsin-HCl digest solution. Abundances of larvae in euphausiids ranged from 0 to 58.2 × 10-5. Larvae (N = 100) were in the third stage (bearing one cuticle) or moulting from the second stage to the third stage (bearing two cuticles). Euphausiids, particularly T. raschii, which represented 98% of the total euphausiids sampled, are important intermediate hosts of A. simplex in the St. Lawrence estuary. These data indicate the importance of the St. Lawrence estuary as an enzootic zone for A. simplex and thus a valuable area to study the biology and the transmission of this parasite.

Utility of Meristic and Morphometric Characters for Identification of Capelin (Mallotus villosus) Stocks in Canadian Atlantic Waters

1978 ◽  
Vol 35 (1) ◽  
pp. 124-130 ◽  
Author(s):  
Joan C. Sharp ◽  
Kenneth W. Able ◽  
William C. Leggett ◽  
James E. Carscadden
Keyword(s):  
Mallotus Villosus ◽  
Meristic Characters ◽  
Body Depth ◽  
Morphometric Characters ◽  
Lawrence Estuary ◽  
Grand Banks ◽  
Capelin Mallotus Villosus ◽  
Statistical Separation ◽  
And Migration ◽  
St Lawrence Estuary

Multivariate discriminant function analyses were performed on 9 morphometric and 11 meristic characters of capelin (Mallotus villosus) samples at Île aux Coudres in the St. Lawrence estuary; Sept Îles, Natashquan, and Grande Rivière in the Gulf of St. Lawrence; Southeast Shoal on the Grand Banks; and Herring Neck, Notre Dame Bay, Newfoundland. Analyses of meristic characters provided no evidence of discrete stocks. Analyses of morphometric characters provided strong statistical separation between areas. A posteriori classification of groups yielded 93.1% correct classification for males and 73.3% for females. Only snout length, eye diameter, head length, and body depth contributed significantly to the separation obtained. These findings suggest that meristic characters offer little potential for stock identification in Canadian Atlantic waters. Morphometric characters may prove useful, but further study, corroborated with life history and migration data, is required to confirm this. Key words: capelin, Mallotus villosus, meristics, morphometrics, stock separation, Gulf of St. Lawrence, Newfoundland, Canadian Atlantic, multivariate analysis

Seasonal Distribution, Abundance, and Growth of Larval Capelin (Mallotus villosus) in the St. Lawrence Estuary and Northwestern Gulf of St. Lawrence

1977 ◽  
Vol 34 (11) ◽  
pp. 2008-2014 ◽  
Author(s):  
Bernadette Jacquaz ◽  
Kenneth W. Able ◽  
William C. Leggett
Keyword(s):  
Primary Production ◽  
Larval Transport ◽  
Larval Abundance ◽  
Mallotus Villosus ◽  
Daily Growth ◽  
Lawrence Estuary ◽  
Capelin Mallotus Villosus ◽  
Feeding Area ◽  
Anticosti Island ◽  
St Lawrence Estuary

Capelin (Mallotus villosus) larvae in the St. Lawrence estuary and northwestern Gulf of St. Lawrence were most abundant in 1974 and 1975 in the upper estuary in early June; this coincided with the spring peak in primary production. A spectacular decline (>99%) in larval abundance between June and September resulted principally from their downstream transport by currents. In October and November larval capelin were concentrated in a large counterclockwise gyre located in the northwestern Gulf between Anticosti Island and Pointe des Monts. This region is within the area of maximum primary production in the estuary and Gulf and may serve as an important feeding area for larval capelin. Length of capelin larvae at the end of the first growing season in the estuary and northwestern Gulf was greater than that of capelin from Newfoundland, Labrador, and Greenland. However, this difference may have resulted from sampling biases. Daily growth rates of capelin larvae from these areas were similar. Key words: capelin, Mallotus villosus, St. Lawrence, seasonal distributions, larval transport, growth, vertical distribution

Euphausiids as intermediate hosts of Anisakis simplex in the St. Lawrence estuary

1998 ◽  
Vol 76 (7) ◽  
pp. 1226-1235 ◽  
Author(s):  
Réjean Hays ◽  
Lena N. Measures ◽  
Jean Huot
Keyword(s):  
Anisakis Simplex ◽  
Intermediate Hosts ◽  
Lawrence Estuary ◽  
St Lawrence Estuary

Patterns of Larval Emergence and Their Potential Impact on Stock Differentiation in Beach Spawning Capelin (Mallotus villosus)

1987 ◽  
Vol 44 (7) ◽  
pp. 1326-1336 ◽  
Author(s):  
Louis Fortier ◽  
William C. Leggett ◽  
Serge Gosselin
Keyword(s):  
Dark Phase ◽  
Mallotus Villosus ◽  
Lawrence Estuary ◽  
Larval Stages ◽  
Abrupt Changes ◽  
Capelin Mallotus Villosus ◽  
Larval Emergence ◽  
Laboratory Emergence ◽  
St Lawrence Estuary ◽  
Stock Differentiation

The environmental cues triggering larval capelin (Mallotus villosus) emergence in the St. Lawrence estuary and in coastal Newfoundland are different. In the estuary, emergence from the intertidal and subtidal spawning grounds starts with dusk and ends with dawn, indicating an active response to low light intensity. In the laboratory, emergence from undisturbed sediments collected in the field is perfectly synchronized with the dark phase of the illumination cycle. Nocturnal emergence would represent an adaptation reducing vulnerability to visual predators. Previous work has shown that in Newfoundland, capelin emergence from intertidal beaches is triggered by abrupt changes in water temperature following the sporadic advection to the coast of surface water masses characterized by low predator and high prey abundances. We argue that regional differences in the emergence pattern of the species represent different strategies to avoid predation at the onset of the planktonic drift when the vulnerable yolk sac larvae are densely aggregated. Selection acting on the behaviour of the early larval stages could contribute to stock differentiation in capelin.

Helminths of an endangered population of belugas, Delphinapterus leucas, in the St. Lawrence estuary, Canada

1995 ◽  
Vol 73 (8) ◽  
pp. 1402-1409 ◽  
Author(s):  
L. N. Measures ◽  
P. Béland ◽  
D. Martineau ◽  
S. De Guise
Keyword(s):  
Host Record ◽  
Anisakis Simplex ◽  
Morbidity And Mortality ◽  
The Arctic ◽  
Delphinapterus Leucas ◽  
New Host ◽  
Lawrence Estuary ◽  
New Host Record ◽  
Endangered Population ◽  
St Lawrence Estuary

Helminths were identified in 38 belugas, Delphinapterus leucas, stranded in the St. Lawrence estuary and Gulf of St. Lawrence during 1984–1993. These helminth species were Anisakis simplex, Contracaecinea sp., Pseudoterranova sp., Stenurus arctomarinus, Pharurus pallasii, Halocercus taurica (new host record), Halocercus monoceris (new host record), Hadwenius seymouri, Diphyllobothrium sp., and Bolbosoma sp. (new host record). Of 21 helminths previously reported from populations of belugas worldwide, 7 were found in the St. Lawrence population. Lungworms, such as Halocercus monoceris, may prove useful in identification of beluga populations in the Arctic and may also be an important cause of morbidity and mortality of calves.

Seasonal distribution, abundance, and growth of larval capelin (Mallotus villosus) and the role of the Lower Estuary (Gulf of St. Lawrence, Canada) as a nursery area

2013 ◽  
Vol 70 (10) ◽  
pp. 1508-1530 ◽  
Author(s):  
Patrick Ouellet ◽  
Alice Olga Victoria Bui ◽  
Diane Lavoie ◽  
Joël Chassé ◽  
Nicolas Lambert ◽  
...  
Keyword(s):  
Size Structure ◽  
Larval Growth ◽  
Lower Estuary ◽  
Mallotus Villosus ◽  
Lawrence Estuary ◽  
Particle Tracking Model ◽  
Capelin Mallotus Villosus ◽  
Tracking Model ◽  
St Lawrence Estuary

Capelin (Mallotus villosus) spawning in the St. Lawrence Estuary is concentrated in the Upper Estuary (UE). The northwest Gulf of St. Lawrence (NW GSL) was presented as the principal nursery for capelin originating from the estuary. In 2009 and 2010, we investigated the abundance, distribution, and size structure of capelin larvae in this system, and a particle tracking model was used to simulate larval dispersion. There was evidence of retention and larval growth in the Lower Estuary (LE), and older larvae were found in the LE by the end of summer. In October 2009, it was possible to link the cohorts of large larvae to emergence events in the UE in spring. Capelin larvae were more abundant or bigger (mean length) in the LE relative to the NW GSL in fall 2006, 2008, and 2009. We conclude that the LE is the habitat of a unit of the GSL capelin population composed of individuals that are retained in this region following hatching in the UE and that there is limited mixing with larvae originating in the NW GSL.

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

1995 ◽  
Vol 52 (S1) ◽  
pp. 246-253 ◽  
Author(s):  
J.R. Arthur ◽  
E. Albert ◽  
F. Boily
Keyword(s):  
Parasite Fauna ◽  
Mallotus Villosus ◽  
New Host ◽  
Lawrence Estuary ◽  
Pseudoterranova Decipiens ◽  
Capelin Mallotus Villosus ◽  
High Level ◽  
St Lawrence Estuary ◽  
Hysterothylacium Aduncum ◽  
New Host Records

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).

Concentration of capelin (Mallotus villosus) in tidal upwelling fronts at the head of the Laurentian Channel in the St. Lawrence estuary

1999 ◽  
Vol 56 (10) ◽  
pp. 1832-1848 ◽  
Author(s):  
Caroline Marchand ◽  
Yvan Simard ◽  
Yves Gratton
Keyword(s):  
Tidal Cycle ◽  
High Tide ◽  
Stomach Contents ◽  
Mallotus Villosus ◽  
Lawrence Estuary ◽  
Threshold Response ◽  
Capelin Mallotus Villosus ◽  
Gut Fullness ◽  
St Lawrence Estuary ◽  
Upwelling Area

In 1994 and 1995, continuous monitoring of physical characteristics and echo integration were used to detect aggregations of capelin (Mallotus villosus) in the upper water column in relation to thermal fronts and to examine the tidal dynamics in an intense upwelling area at the head of the Laurentian Channel. During the four cruises, fish aggregations were recorded for 72% of the fronts (n = 61) resulting from the periodic upwelling of cold waters. Over the tidal cycle, only a low fish biomass was detected when the cold intermediate waters (<2°C) upwelled during high tide; 90% of the 2-year-old capelin biomass was detected in water temperatures >2°C. Capelin zooplankton prey were concentrated primarily over the deep Laurentian Channel, with very small numbers being found in the shallower areas nearby, where the fronts occurred. The prey concentrations did not increase at the fronts at any phase of the tidal cycle. The few zooplankton patches detected by the optical plankton counter did not correspond to either physical structures or fish concentrations. The gut fullness index and the stomach contents of the capelin caught in fronts did not differ from those of capelin caught elsewhere. These frontal aggregations of capelin seem therefore to be driven more by a threshold response to low temperatures than by trophic interactions based on a higher prey density.

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