Individual-based modeling explains the contrasted seasonality in size, growth, and reproduction of the sympatric Arctic (Thysanoessa raschii
) and Nordic krill (Meganyctiphanes norvegica
) in the St. Lawrence Estuary, eastern Canada

From a study of living materials and specimens in several regional herbaria, a list has been drawn up of all the common and several of the rarer tube-dwelling diatoms of eastern Canada. Descriptions, illustrations of living material and acid-cleaned valves, and a key to the species are provided. Most specimens were from the Atlantic Provinces and the St. Lawrence estuary, but a few were from the Northwest Territories. By far the most common species is Berkeleya rutilans. Other species occurring commonly in the Quoddy Region of the Bay of Fundy, and sporadically in space and time elsewhere, arc Navicula delognei (two forms), Nav. pseudocomoides, Nav. smithii, Haslea crucigera, and a new species, Nav.rusticensis. Navicula ramosissima and Nav. mollis in eastern Canada are usually found as scattered cohabitants in tubes of other species. Nitzschia tubicola and Nz. fontifuga also occur sporadically as cohabitants.

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Role of the bedrock topography in the Quaternary filling of a giant estuarine basin: the Lower St. Lawrence Estuary, Eastern Canada

Basin Research ◽

10.1111/j.1365-2117.2009.00457.x ◽

2010 ◽

Cited By ~ 12

Author(s):

Mathieu J. Duchesne ◽

Nicolas Pinet ◽

Karine Bédard ◽

Guillaume St-Onge ◽

Patrick Lajeunesse ◽

...

Keyword(s):

Eastern Canada ◽

Lawrence Estuary ◽

Bedrock Topography ◽

St Lawrence Estuary

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Do Barrow's Goldeneyes, Bucephala islandica, Breed South of the St. Lawrence Estuary in the Gaspé Peninsula, Eastern Canada?

The Canadian Field-Naturalist ◽

10.22621/cfn.v124i2.1057 ◽

2010 ◽

Vol 124 (2) ◽

pp. 179

Author(s):

Jean-François Ouellet ◽

Pierre Fradette ◽

Isabel Blouin

Keyword(s):

North America ◽

Breeding Season ◽

Breeding Habitat ◽

Eastern North America ◽

Eastern Canada ◽

Lawrence Estuary ◽

North Shore ◽

The North ◽

Bucephala Islandica ◽

St Lawrence Estuary

We report the first observations of Barrow's Goldeneyes south of the St. Lawrence estuary in typical breeding habitat during the breeding season. Until recently, the confirmed breeding locations for the species in Eastern North America were all located on the north shore of the Estuary and Gulf of St. Lawrence.

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

Canadian Journal of Zoology ◽

10.1139/z98-052 ◽

1998 ◽

Vol 76 (7) ◽

pp. 1226-1235 ◽

Cited By ~ 19

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.

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Identification and dating of a key Late Pleistocene stratigraphic unit in the St. Lawrence Estuary and Gulf (Eastern Canada)

Quaternary Science Reviews ◽

10.1016/j.quascirev.2008.08.023 ◽

2008 ◽

Vol 27 (25-26) ◽

pp. 2390-2400 ◽

Cited By ~ 31

Author(s):

Guillaume St-Onge ◽

Patrick Lajeunesse ◽

Mathieu J. Duchesne ◽

Hubert Gagné

Keyword(s):

Late Pleistocene ◽

Eastern Canada ◽

Lawrence Estuary ◽

Stratigraphic Unit ◽

St Lawrence Estuary

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Recherches sur les Alaria (Phaeophyceae) de l'est canadien. I. Nombres chromosomiques et identité des Alaria de l'estuaire du St-Laurent

Canadian Journal of Botany ◽

10.1139/b74-088 ◽

1974 ◽

Vol 52 (4) ◽

pp. 691-694 ◽

Cited By ~ 2

Author(s):

M.-J. Feller-Demalsy ◽

P. Demalsy

Keyword(s):

Chromosome Number ◽

Single Species ◽

Chromosome Counts ◽

Eastern Canada ◽

Lawrence Estuary ◽

Haploid Chromosome Number ◽

Biosystematic Study ◽

Alaria Esculenta ◽

St Lawrence Estuary

Chromosome counts in gametophytes and sporophylls of Alaria collected in the St. Lawrence Estuary show that all the specimens of this genus in eastern Canada may not belong to the single species A. esculenta Greville. Indeed, the haploid chromosome number (n) found in these algae is equal to half of the number attributed in the literature to Alaria esculenta from the British coasts. Three hypotheses for the interpretation of these observations are considered. The solution of the problem of the identity of Alaria can only be hoped for from their global, morphological, and biosystematic study.

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Diet and feeding behaviour of the sea cucumber Cucumaria frondosa in the St. Lawrence estuary, eastern Canada

Canadian Journal of Zoology ◽

10.1139/z98-040 ◽

1998 ◽

Vol 76 (6) ◽

pp. 1194-1198 ◽

Cited By ~ 42

Author(s):

Jean-Francois Hamel ◽

Annie Mercier

Keyword(s):

Feeding Behaviour ◽

Field Experiments ◽

Skeletonema Costatum ◽

Physical Parameters ◽

Tidal Variation ◽

Eastern Canada ◽

Lawrence Estuary ◽

Laboratory Conditions ◽

St Lawrence Estuary ◽

Cucumaria Frondosa

Combined laboratory and field experiments showed that sea cucumbers (Cucumaria frondosa) from the St. Lawrence estuary in eastern Canada have well-defined feeding cycles with marked seasonal and tidal variations. Typical feeding behaviour involved extension of the tentacles, which were then successively introduced into the oral cavity. Field observations and analysis of intestinal contents and indices demonstrated that C. frondosa fed mainly during spring and summer. Their diet comprised an abundance of phytoplanktonic cells (Coscinodiscus centralis, Chaetoceros debilis, Skeletonema costatum, and Thalassiosira gravida), with occasional ingestion of small crustaceans and a variety of eggs and larvae. Food types found in the digestive tract were closely related to the periodic abundance of plankton species in the water. Fewer individuals were observed feeding during fall and winter; they mostly ingested nonliving particles and the intestinal indices were low. In field populations, feeding rates were highest during ebb and rising tides, whereas under laboratory conditions without tidal variation, individuals showed no distinct feeding periods. However, individuals maintained under laboratory conditions and periodically provided with phytoplanktonic cells demonstrated a strong ability to detect the food in the water and react accordingly by extending their tentacles and beginning to feed. The results of the study suggest that food availability, rather than physical parameters such as temperature or current, best explains the cyclic feeding behaviour of C.\x11frondosa at seasonal and tidal scales.

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