Les groupements benthiques du fleuve Saint-Laurent près des centrales nucléaires de Gentilly (Québec)

1978 ◽  
Vol 56 (7) ◽  
pp. 1585-1592 ◽  
Author(s):  
B. Vincent ◽  
G. Vaillancourt
Keyword(s):  
Present State ◽  
Littoral Zone ◽  
Dominant Species ◽  
Nuclear Reactors ◽  
Deep Waters ◽  
Limnodrilus Hoffmeisteri ◽  
Sublittoral Zone ◽  
Bithynia Tentaculata ◽  
Lotic Environment ◽  
St Lawrence River

The structure and distribution of the macrobenthos were determined to evaluate the present state of the section of the St. Lawrence River which might be affected by the cooling waters of the Gentilly nuclear reactors. Ten groups were recognized, characterized by the presence of one to three constant and dominant species. In lentic conditions characterized by the presence of the gastropod Bithynia tentaculata the zonation is depth dependent. Three groups inhabit the littoral zone characterized by the Glossoscolecidae Sparganophilus tamesis. There are two groups in the sublittoral zone characterized by the Tubificidae Limnodrilus hoffmeisteri and two groups in the deep waters characterized by the Sphaeriidae Sphaerium striatinum. Bithynia tentaculata, a hydrobiid, seldom inhibits the lotic environment where the Tubificidae Limnodrilus hoffmeisteri is the only typical species.

scholarly journals The fauna and benthic communities of invertebrates of the Ural river within the Atuar steppe (Orenburg state nature reserve)

2021 ◽  
pp. 275-288
Author(s):  
Tat'yana S. Krayneva ◽  
◽  
Nikolaj N. Pan'kov ◽  
Keyword(s):  
Nature Reserve ◽  
Benthic Communities ◽  
Water Bodies ◽  
Chironomid Larvae ◽  
Sandy Gravel ◽  
Limnodrilus Hoffmeisteri ◽  
Bithynia Tentaculata ◽  
State Nature Reserve ◽  
Bristle Worms ◽  
State Nature

There are 70 species and forms in the composition of zoobenthos of the river Ural and in water bodies of its floodplain have been identified. Mayflies and chironomids are represented in various ways (13 and 12 species and forms, respectively). Caddisflies (10) and stone flies (7) are rich in species. Among other invertebrates, bivalves (6) and gastropods (5), small-bristled worms (5), non-chironomid dipterans (4), leeches, crustaceans and dragonflies, bugs and beetles were recorded. On sandy-gravel-pebble soils is formed a zoobenthocenosis, dominated by the mayflies Ephoron virgo. They are accompanied by Chironomidae larvae. The biomass of the community varies between of 29.32–31.68 g/m2 with an abundance of 18.1–32.44 thousand ind./m2. In the coastal of the channel is formed a pelophilic zoobenthocenosis, the basis of it abundance and biomass are constituted by the small-bristle worms Limnodrilus hoffmeisteri. They are accompanied by mollusks Stagnicola palustris and mysids P. lacustris. The biomass of the pelophilic community is 13.68 g/m2 with a population of 15.45 thousand ind./m2. In floodplain water bodies are formed pelophilic zoobenthocenoses, the biomass of which varies in the range of 19.2–34.24 g/m2 with an abundance of 5.64–30.04 thousand ind./m2. Chironomid larvae constitute the base of the population. The biomass is composed by dragonflies Libellula sp., Chironomids, and mollusks Bithynia tentaculata.

Cycle de développement, croissance et production de Pisidium amnicum (Mollusca: Bivalvia) dans le Saint-Laurent (Québec)

1981 ◽  
Vol 59 (12) ◽  
pp. 2350-2359 ◽  
Author(s):  
B. Vincent ◽  
G. Vaillancourt ◽  
N. Lafontaine
Keyword(s):  
Population Dynamics ◽  
Sexual Maturity ◽  
Dry Weight ◽  
Mortality Rates ◽  
The Other ◽  
Annual Production ◽  
Bithynia Tentaculata ◽  
The Mean ◽  
Total Dry Weight ◽  
St Lawrence River

The population dynamics of Pisidium amnicum have been studied in one population of the St. Lawrence River over a 2-year period during which 19 samples were taken. The species can live up to 3 years and it is iteroparous; individuals generally attain sexual maturity after 1 year and they reproduce twice, once at 2 and once at 3 years of age. In adults, mortality is lower in winter than during the rest of the year and mortality rates are twice as high during the 1st year than during the 2nd year. Total dry weight (PT, in milligrams) is related to maximum length (L, in millimetres) according to the equation PT = 0.0283∙L3,80 and flesh dry weight (PC, in milligrams) is related to length as follows: PC = 0.007∙L3,18. The annual production to mean biomass (P/B) ratio is 1.4, the mean annual production being 1.298 mg/m2 of total dry weight and 107 mg/m2 of flesh weight. Comparing these results with those obtained for the gastropod Bithynia tentaculata in the same environment and at the same period of the year has shown that the growth of Pisidium amnicum is far less influenced by the temperature regime than that of the other species and that its production is at least 10 times lower.

Age-, size-, and sex-specific infection of Anodonta piscinalis (Bivalvia: Unionidae) with Rhipidocotyle fennica (Digenea: Bucephalidae) and its influence on host reproduction

1995 ◽  
Vol 73 (5) ◽  
pp. 887-897 ◽  
Author(s):  
Jouni Taskinen ◽  
E. Tellervo Valtonen
Keyword(s):  
Significant Interaction ◽  
Littoral Zone ◽  
Linear Models ◽  
Host Size ◽  
Logit Models ◽  
Fast Growing ◽  
Sublittoral Zone ◽  
Log Linear ◽  
Anodonta Piscinalis

A Rhipidocotyle fennica infection in Anodonta piscinalis was studied during 1987–1989 in Lake Saravesi, central Finland. The overall prevalence was 32.3% (n = 1157). Only mature clams, ≥ 3 and ≥ 4 years old in the littoral and sublittoral zones, respectively, were infected. According to log-linear models constructed for the mature clams, there was a statistically significant interaction between prevalence and age of the host, between prevalence and habitat, and between age of the host and habitat; prevalences were higher among old specimens and in the littoral zone than among young clams or in the sublittoral zone. Logit models showed that prevalence increased linearly with host size in both habitats. A relationship between clam growth and infection was also found: fast-growing clams were more often infected or infected clams had grown faster. The quantity of sporocyst tubules increased with the age of the host. Prevalence was higher among female clams than among males. It was estimated that over 50% of mature females in the littoral zone were infected. It was also estimated that there was a 31% reduction in the number of glochidium-bearing clams in the littoral zone of Lake Saravesi due to infection with this parasite.

Étude du benthos d'eau douce dans le haut-estuaire du Saint-Laurent (Québec)

1979 ◽  
Vol 57 (11) ◽  
pp. 2171-2182 ◽  
Author(s):  
B. Vincent
Keyword(s):  
Dominant Species ◽  
Gradual Change ◽  
Lower Section ◽  
St Lawrence River

Benthos samples collected in 37 sites interspersed along a 230 km stretch of the St. Lawrence River, between Lake St. Pierre and Ile aux Oies, were analyzed. The distribution of the main taxa shows the downstream succession of many of the dominant species. Benthic groups of the upstream and downstream sections of the upper estuary are characterized by the hydrobiid B. tentaculata and the viviparid V. georgianus, respectively. The structure of the benthic groups undergoes a gradual change downstream from Gentilly and the samples collected in the lower section add up to a much more heterogeneous community than the samples collected in the upper or the middle reaches of the estuary.[Journal Translation]

Paper 28: Bearings for Nuclear Engineering

1967 ◽  
Vol 182 (1) ◽  
pp. 449-459
Author(s):  
H. H. Heath
Keyword(s):  
Research And Development ◽  
Present State ◽  
Nuclear Reactors ◽  
Nuclear Engineering ◽  
Design Practice ◽  
State Of Research

Problems affecting the use of bearings and lubricants in nuclear reactors are discussed and the present state of research and development reviewed. Some comments on design practice and procedures are included.

Relationships between total mercury in sediments and methyl mercury in the freshwater gastropod prosobranch Bithynia tentaculata in the St. Lawrence River, Quebec

2000 ◽  
Vol 57 (S1) ◽  
pp. 164-173 ◽  
Author(s):  
JC Désy ◽  
J -F Archambault ◽  
B Pinel-Alloul ◽  
J Hubert ◽  
P GC Campbell
Keyword(s):  
Methyl Mercury ◽  
Linear Models ◽  
Dry Weight ◽  
Gut Contents ◽  
Freshwater Gastropod ◽  
Bithynia Tentaculata ◽  
Total Hg ◽  
Highly Correlated ◽  
The Relationship ◽  
St Lawrence River

Total Hg concentrations in sediment and methyl mercury (MeHg) levels in the gastropod species Bithynia tentaculata were evaluated at 21 stations in the fluvial corridor of the St. Lawrence River (Quebec, Canada). In the sediments (n = 21), total Hg concentrations ranged from 34 to 2790 ng·g dry weight-1. In the gastropods, MeHg concentrations varied from 15 to 290 ng·g dry weight-1 in undepurated gastropods (n = 20) and from 41 to 420 ng·g dry weight-1 in depurated gastropods (n = 13; without gut contents). The southern sector of Lake St. Louis, located near the Îles-de-la-Paix, had significantly higher Hg concentrations than any other sectors under study, both for total Hg in the sediments and MeHg in the gastropods. We established linear models to describe the relationships between Hg contamination in sediments and molluscs for the fluvial corridor of the St. Lawrence River and for the Lake St. Louis sector. Total Hg in sediments and MeHg in gastropods were highly correlated for all pooled stations (r = 0.83), and the relationship was even stronger for the Lake St. Louis stations (r = 0.92). Our study suggests that the gastropod B. tentaculata is a promising biomonitor species for assessing Hg contamination in the fluvial corridor and lakes of the St. Lawrence River.

Metal concentrations in two freshwater gastropods (Mollusca) in the St. Lawrence River and relationships with environmental contamination

2000 ◽  
Vol 57 (S1) ◽  
pp. 126-137 ◽  
Author(s):  
Christiane Flessas ◽  
Yves Couillard ◽  
Bernadette Pinel-Alloul ◽  
Louise St-Cyr ◽  
Peter GC Campbell
Keyword(s):  
Metal Ion ◽  
Metal Concentrations ◽  
Freshwater Gastropods ◽  
Significant Relationships ◽  
Body Tissues ◽  
Bithynia Tentaculata ◽  
Free Metal ◽  
Sediment Interface ◽  
Potential Use ◽  
St Lawrence River

This study assesses the potential use of two dominant freshwater gastropod species of the St. Lawrence River, Bithynia tentaculata (Prosobranchia) and Physa gyrina (Pulmonata), as biomonitors of metal pollution. Gastropods were collected in the littoral zone of Lake St. Louis and Lake St. Pierre, two shallow fluvial lakes of the St. Lawrence River, at sampling stations chosen to represent a metal concentration gradient in sediments. The soft body tissues of snails were analyzed for Cd, Cu, Ni, Pb, and Zn. Metal concentrations in snail tissues were related to those in macrophytes, on which the snails were collected, and in nearby sediments, where the metal ion concentrations at the water-sediment interface were estimated. There was a significant effect of age on the essential metals Cu and Zn, adults of B. tentaculata showing higher concentrations than juveniles. Significant relationships were obtained between Cd and Zn concentrations in snail tissues and those in the environment (macrophytes or the estimated free metal ion levels at the water-sediment interface). Some other relationships were also obtained with Ni, Pb, and Cu in P. gyrina. Bithynia tentaculata appears to be a promising biomonitor species, particularly for Cd and Zn.

scholarly journals Distribution, morphological variability, ecology and the present state of Nitella from Lake Ohrid and its surroundings

2012 ◽  
Vol 64 (2) ◽  
pp. 549-556 ◽  
Author(s):  
Sonja Trajanovska ◽  
Jelena Blazencic ◽  
S. Trajanovski ◽  
Biljana Budzakoska-Gjoreska
Keyword(s):  
Present State ◽  
Littoral Zone ◽  
Morphological Variability ◽  
Lake Ohrid ◽  
Negative State ◽  
Specific Distribution ◽  
Rapid Reaction ◽  
Complex Monitoring ◽  
Detailed Picture

Our research into 52 profiles of the littoral zone of the Macedonian part of Lake Ohrid and numerous samples taken from its surroundings has resulted in a detailed picture of the composition of the Charophyta vegetation in the lake. The results of the research also include data regarding the species composition and present state of Nitella. The dominant species of Nitella is Nitella opaca, which is characterized by a specific distribution, morphological variability and ecology. The present state of Nitella is not steady, especially in the watershed of the lake, since in this area there are some permanent changes in the hydrology of the terrain. Therefore, there is a need to establish long-term and complex monitoring which will result in the prompt detection of risk factors and influences, thereby enabling a rapid reaction to a possible newly emerged negative state.

Étude expérimentale in situ des effets de la densité et de la quantité de nourriture chez le gastéropode Bithynia tentaculata (Mollusca: Prosobranchia)

1986 ◽  
Vol 64 (8) ◽  
pp. 1696-1700 ◽  
Author(s):  
Eric Gilbert ◽  
Bruno Vincent ◽  
Luc Roseberry
Keyword(s):  
Natural Environment ◽  
Adult Mortality ◽  
Adult Density ◽  
Initial Value ◽  
Bithynia Tentaculata ◽  
Two Factors ◽  
The Mean ◽  
New Generation ◽  
St Lawrence River

Experiments in a natural environment on the Gastropod Bithynia tentaculata showed that adult density and available food have significant effects on the growth of smaller adults and newborns. Mean length of the new generation at the end of the experiment incresed as adult densities decreased from the initial value and as food abundance increased. The only case of interaction between these two factors can be explained by an increase in the number of young brought about by the addition of food when density was low and by the influence of the density of these young on their growth. Different combinations of density and food can produce the various types of length–frequency histograms observed in a natural environment and during the past 8 years in the St. Lawrence River. There was no significant correlation between these two factors and the adult mortality rate, but density did have a significant effect on the mean number of young per adult.[Journal translation]

Méthode de détermination de l'âge, longévité et croissance annuelle de Bithynia tentaculata L. (Gastropoda: Prosobranchia) dans le Saint-Laurent (Québec)

1981 ◽  
Vol 59 (6) ◽  
pp. 982-985 ◽  
Author(s):  
B. Vincent ◽  
G. Vaillancourt
Keyword(s):  
Accurate Determination ◽  
Annual Growth ◽  
Bithynia Tentaculata ◽  
St Lawrence River

In the St. Lawrence River, shells of Bithynia tentaculata bear annual growth lines that form at the end of each winter. These lines allow accurate determination of age since they can be easily counted and are present in all types of habitat. Longevity was determined by this method: B. tentaculata lives about 32 to 39 months and can sometimes reach 48 to 51 months of age. Annual growth is more important during the 2nd than during the 1st year (4.0 mm and 300 mm, respectively) and it is reduced during the 3rd year (0.7 mm).[Journal translation]

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