Interactions multispécifiques: répartition spatio-temporelle des larves de capelan (Mallotus villosus), d'éperlan (Osmerus mordax) et de hareng de l'Atlantique (Clupea harengus harengus) an sein de la communauté planctonique de l'estuaire moyen du Saint-Laurent

1982 ◽  
Vol 39 (8) ◽  
pp. 1164-1174 ◽  
Author(s):  
R. Courtois ◽  
M. Simoneau ◽  
J. J. Dodson
Keyword(s):  
Fish Larvae ◽  
Clupea Harengus ◽  
Temporal Organization ◽  
Physical Factors ◽  
Osmerus Mordax ◽  
Mallotus Villosus ◽  
Saint Lawrence River ◽  
Capelin Mallotus Villosus ◽  
Clupea Harengus Harengus ◽  
Species Specific

The study of the spatial and temporal organization of the planktonic community of the middle estuary of the Saint Lawrence River revealed that fish larvae were distributed in such a way as to minimize interactions between species. Smelt (Osmerus mordax) larvae were distributed upstream whereas capelin (Mallotus villosus) and Atlantic herring (Clupea harengus harengus) larvae were found downstream in June 1979. Capelin larvae were more abundant at the surface (0–20 m) whereas herring larvae were concentrated in deeper waters (20–60 m). The ecological separation observed was maintained by multiple physical factors and appeared to be the consequence of species-specific reproductive strategies. The abundance of chaetognaths, euphausiids, and amphipods in deeper waters suggests that these forms could be important predators of fish larvae. Herring larvae may be particularly vulnerable because of their distribution in deep water. Capelin larvae which are very abundant in June could also be vulnerable to predation during the diurnal migrations of the macroplankton. Smelt larvae appear to be little affected by predation from these forms as a result of their distribution in fresher waters.

Effects of predation from juvenile herring (Clupea harengus) on mortality rates of capelin (Mallotus villosus) larvae

2009 ◽  
Vol 66 (10) ◽  
pp. 1693-1706 ◽  
Author(s):  
Elvar H. Hallfredsson ◽  
Torstein Pedersen
Keyword(s):  
Barents Sea ◽  
Fish Larvae ◽  
Mortality Rates ◽  
Clupea Harengus ◽  
Mallotus Villosus ◽  
Rate Estimate ◽  
Predator Prey ◽  
The Barents Sea ◽  
Capelin Mallotus Villosus ◽  
Larvae Density

Predation has been suggested as a cause of substantial mortality of fish larvae to the degree that it might influence recruitment. This field-based study concludes that juvenile herring ( Clupea harengus ) as small pelagic predator can significantly affect mortality rates of the planktonic larvae of capelin ( Mallotus villosus ) in the Barents Sea. Surveys were carried out in the summers of 2001 and 2003. In 2001, juvenile herring were widely distributed and overlapped with capelin larvae over a wide area, whereas in 2003, the herring were more aggregated. The study focused on predation in the areas of predator–prey overlap. Capelin larvae were observed in the herring stomachs at 11 of 24 stations and at 8 of 16 stations where herring were caught in 2001 and 2003, respectively. At those stations, an estimated 7.3% and 9.9% of the capelin larvae were eaten by herring per day in 2001 and 2003, respectively. Statistical models revealed that density of capelin larvae and copepods and occurrence of euphausiids in the stomachs affected the number of capelin larvae per predator stomach. A simplified model with only capelin larvae density as predictor was converted to a functional response relationship using an experimentally derived digestion rate estimate for capelin larvae in herring stomachs.

Chemical and Sensory Analysis of Ungutted Offshore (Nonspawning) Capelin (Mallotus villosus) Stored in Ice

1978 ◽  
Vol 35 (7) ◽  
pp. 976-980 ◽  
Author(s):  
J. R. Botta ◽  
P. B. Noonan ◽  
J. T. Lauder
Keyword(s):  
Peroxide Value ◽  
Sensory Quality ◽  
Clupea Harengus ◽  
Mallotus Villosus ◽  
Overall Acceptability ◽  
Atlantic Mackerel ◽  
Muscle Ph ◽  
Capelin Mallotus Villosus ◽  
Clupea Harengus Harengus ◽  
Iced Storage

Based on changes in chemical and sensory variables, the keeping time of ungutted offshore capelin (Mallotus villosus) stored in ice was ~ 12 d, which was superior to other pelagic fish such as inshore (spawning) male capelin, Atlantic herring (Clupea harengus harengus) and Atlantic mackerel (Scomber scombrus). Free fatty acid, hypoxanthine, trimethylamine, and moisture content as well as iodine number and muscle pH significantly (P ≤ 0.05) changed during 16 d of iced storage. Although changes in lipid content and peroxide value were statistically significant (P ≤ 0.05), it is questionable whether these changes were chemically significant. Hypoxanthine and trimethylamine appeared to have the most potential for use as indices of sensory quality deterioration during iced storage. Key words: capelin, flavor, free fatty acids (FFA), hypoxanthine, iced storage, odor, overall acceptability, peroxide value, texture, trimethylamine (TMA)

Small-Scale Covariability in the Abundance of Fish Larvae and Their Prey

1984 ◽  
Vol 41 (3) ◽  
pp. 502-512 ◽  
Author(s):  
L. Fortier ◽  
W. C. Leggett
Keyword(s):  
Large Scale ◽  
Larval Fish ◽  
Fish Larvae ◽  
Spatial Scales ◽  
Low Frequency ◽  
Clupea Harengus ◽  
Differential Mortality ◽  
Small Scale ◽  
Capelin Mallotus Villosus ◽  
Clupea Harengus Harengus

We studied the covariability in the abundance of larval fish and rnicrozooplankton at a fixed station of the St. Lawrence upper estuary. Hourly sampling during 129 h combined with net and tidal circulations allowed us to resolve spatial scales of approximately 2 km to several tens of kilometres. Low-frequency fluctuations in the abundance of larval capelin (Mallotus villosus) and larval Atlantic herring (Clupea harengus harengus) reflected the advection past the station of successive cohorts. Large-scale horizontal gradients in abundance and length were apparently formed at the emergence of the larvae from the spawning beds. The majority of capelin larvae we sampled had not yet completely exhausted their yolk reserves. There was no indication that differential mortality or active swimming had produced a concordance between the distribution of this species and the distribution of microzooplankton. Herring larvae resorbed their yolk sac and began mandatory exogenous feeding during the period of sampling. Tidal and subtidal patterns of variation in the abundance of this species and microzooplankton became significantly coherent after the resorption of the vitelline reserves. The possible mechanisms giving rise to coherence at these two different scales are considered in light of published information on the feeding behavior and swimming capacity of herring larvae.

Isolation and characterization of antifreeze proteins from smelt (Osmerus mordax) and Atlantic herring (Clupea harengus harengus)

1990 ◽  
Vol 68 (8) ◽  
pp. 1652-1658 ◽  
Author(s):  
K. Vanya Ewart ◽  
Garth L. Fletcher
Keyword(s):  
Antifreeze Proteins ◽  
Gel Filtration ◽  
Exchange Chromatography ◽  
Clupea Harengus ◽  
Osmerus Mordax ◽  
Atlantic Herring ◽  
Activity Levels ◽  
Isolation And Characterization ◽  
Sea Raven ◽  
Clupea Harengus Harengus

Antifreeze proteins (AFPs) from smelt (Osmerus mordax) and Atlantic herring (Clupea harengus harengus) were isolated using gel filtration, ion exchange chromatography, and high performance liquid chromatography. The AFPs of smelt appeared to consist of at least six components and those of Atlantic herring, of at least two components. The relative molecular masses of these antifreezes were 24 000 and 14 600, respectively. Amino acid analysis showed both proteins to be cystine-rich, type II AFPs like those of the sea raven (Hemitripterus americanus). In addition, smelt AFPs were found to be immunologically similar to those of the sea raven. The smelt AFPs differed from those of Atlantic herring and sea raven in that they contained a small amount of glucosamine (~3%). The activity levels of the smelt and herring AFPs were reduced in the presence of dithiothreitol, indicating the functional importance of intact disulfide bonds.

Régime alimentaire et principaux facteurs influençant l'alimentation des larves de capelan (Mallotus villosus), d'éperlan (Osmerus mordax) et de hareng (Clupea harengus harengus) dans un estuaire partiellement mélangé

1986 ◽  
Vol 43 (5) ◽  
pp. 968-979 ◽  
Author(s):  
R. Courtois ◽  
J. J. Dodson
Keyword(s):  
Feeding Rate ◽  
Water Masses ◽  
Clupea Harengus ◽  
Gut Contents ◽  
Osmerus Mordax ◽  
Lawrence Estuary ◽  
Daily Cycles ◽  
Food And Feeding ◽  
Clupea Harengus Harengus ◽  
St Lawrence Estuary

The food and feeding rate periodicity of larvae of capelin (Mallotus villiosus), smelt (Osmerus mordax), and herring (Clupea harengus harengus) were studied to determine the existence of potential interactions between the larvae of these three species. Analyses of the gut contents showed that larvae of capelin started to feed before yolk sac absorption but that the feeding rate was low (<20%) in the lower St. Lawrence estuary; the small size of capelin larvae restricted their feeding to tintinnids. Larvae of the two other species feed at a greater rate than capelin larvae and their food is more diverse. The temporal sequence of feeding incidences showed daily cycles for the three species and semidiurnal cycles for larvae of capelin and herring. The importance of light for feeding of larvae was confirmed by the daily cycles and by the greater abundance of larvae with gut contents in surface waters (0–20 m). From the absence of a relation between biotic factors (density of larvae) and the temporal evolution of feeding incidences, we suggest that semidiurnal cycles are mainly related to temperature changes associated with advection of water masses at the sampling stations. Even though similar reactions to certain environmental variables were observed, we concluded that interspecific competition is minimal between larvae of the three species. Although present at the same stations, larvae of different species mainly occurred in distinct water masses; they are also mainly of different size. Those characteristics force them to exploit organisms of different size and mainly of different species.

Capelin (Mallotus villosus) Spawning on the Southeast Shoal: Influence of Physical Factors Past and Present

1989 ◽  
Vol 46 (10) ◽  
pp. 1743-1754 ◽  
Author(s):  
J. E. Carscadden ◽  
K. T. Frank ◽  
D. S. Miller
Keyword(s):  
Surf Zone ◽  
Biological Data ◽  
Published Data ◽  
Physical Factors ◽  
Bottom Temperature ◽  
Mallotus Villosus ◽  
Term Survival ◽  
Grand Banks ◽  
Spawning Stock ◽  
Capelin Mallotus Villosus

Co-occurrence of beach- and offshore bottom-spawning populations of capelin (Mallotus villosus) in the Northwest Atlantic appears to be unusual. To explain the evolution of bottom-spawning in the offshore spawning population on the Southeast Shoal, we examined relevant substrate, water temperature, and biological data. Published data indicate that the Southeast Shoal was not glaciated during the Wisconsin glaciation (about 20 000 yr ago) and was above sea level. As the glaciers melted, this area was a surf zone before it became inundated. This suggests that this stock was once a beach-spawning stock and supports our hypothesis that substrate is the ultimate factor affecting spawning location. Analysis of 7 yr of distribution, maturity, and bottom temperature data showed that the variation in the final spawning location was not large and spawning occurred where bottom temperatures exceeded approximately 2 °C. We conclude that bottom temperature is a proximate factor influencing the final spawning location. Physical data for other areas of the Grand Banks indicate that only the Southeast Shoal has favourable substrate, bottom temperatures and environmental factors subsequent to spawning to allow the long-term survival of a capelin population.

Advection–Diffusion Modelling of Larval Capelin (Mallotus villosus) Dispersion in Conception Bay, Newfoundland

1994 ◽  
Vol 51 (6) ◽  
pp. 1297-1307 ◽  
Author(s):  
Brad deYoung ◽  
John Anderson ◽  
Richard J. Greatbatch ◽  
Paul Fardy
Keyword(s):  
Residence Time ◽  
Diagnostic Model ◽  
Physical Factors ◽  
Surface Mixed Layer ◽  
Mallotus Villosus ◽  
Advection Diffusion ◽  
Capelin Mallotus Villosus ◽  
June July ◽  
Release Location ◽  
Conception Bay

A numerical model was used to determine the residence time of capelin (Mallotus villosus) larvae in Conception Bay, Newfoundland. The larvae were observed in the surface mixed layer of the Bay following release from beaches in June–July in order to examine how they move outside the Bay and what physical factors influence their rate of transport. A diagnostic model of Conception Bay provides a fixed velocity field which drives an advection–diffusion model applied to capelin larval dispersal from the Bay. The model was run for different periods to explore dependence of the residence time on different conditions during the period 1989–90. Model results showed that the residence time depends on the release location of the larvae in the Bay. While the residence time of the larvae does vary, we estimate it to be roughly 30 d for larvae released from the head of the Bay. Residence times are much shorter for larvae near the mouth of the Bay.

scholarly journals Trophic interactions affecting a key ecosystem component: a multistage analysis of the recruitment of the Barents Sea capelin (Mallotus villosus)

2010 ◽  
Vol 67 (9) ◽  
pp. 1363-1375 ◽  
Author(s):  
Dag Øystein Hjermann ◽  
Bjarte Bogstad ◽  
Gjert Endre Dingsør ◽  
Harald Gjøsæter ◽  
Geir Ottersen ◽  
...  
Keyword(s):  
Trophic Interactions ◽  
Gadus Morhua ◽  
Barents Sea ◽  
Clupea Harengus ◽  
Mallotus Villosus ◽  
The Barents Sea ◽  
Key Species ◽  
Capelin Mallotus Villosus ◽  
Ecosystem Component ◽  
Recruitment Stages

The Barents Sea stock of capelin ( Mallotus villosus ) has suffered three major collapses (>90% reduction) since 1985 due to recruitment failures. As capelin is a key species in the area, these population collapses have had major ecosystem consequences. By analysing data on spawner biomass and three recruitment stages (larvae, 0-group, and 1-year-olds), we suggest that much of the recruitment failures are caused by predation from herring ( Clupea harengus ) and 0-group and adult Northeast Arctic cod ( Gadus morhua ). Recruitment is furthermore positively correlated with sea temperatures in winter and spring. Harvesting of maturing capelin on their way to the spawning grounds reduced the abundance of larvae significantly, but this reduction to a large extent is compensated for later in life, as mortality is strongly density-dependent between the larval stage and age 1. Altogether, our study indicates a very high importance of trophic interactions, consistent with similar findings in other high-latitude marine ecosystems.

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