Selective Exploitation of Capelin (Mallotus villosus) Eggs by Winter Flounder (Pseudopleuronectes americanus): Capelin Egg Mortality Rates, and Contribution of Egg Energy to the Annual Growth of Flounder

1984 ◽  
Vol 41 (9) ◽  
pp. 1294-1302 ◽  
Author(s):  
K. T. Frank ◽  
W. C. Leggett
Keyword(s):  
Average Energy ◽  
Winter Flounder ◽  
Annual Growth ◽  
Pseudopleuronectes Americanus ◽  
Mallotus Villosus ◽  
Egg Mortality ◽  
Capelin Mallotus Villosus ◽  
Gonad Production ◽  
Conception Bay ◽  
Spawning Sites

The consequences of winter flounder (Pseudopleuronectes americanus) predation on capelin (Mallotus villosus) eggs, both in terms of the egg mortality and of the contribution of energy ingested to the annual growth of flounder, were investigated at Bryant's Cove, Conception Bay, Newfoundland. Flounder density in the nearshore area adjacent to the capelin spawning beach increased sharply in each of the three study years in response to the presence of spawning capelin and to the density of capelin eggs on the spawning beaches. Capelin eggs were the dominant item inthedietofwinterflounder14–34 cm TL, averaging 59% by weight. Flounder [Formula: see text] fed less heavily on capelin eggs (22% of food consumed by weight) but because of their larger size and ration were an important source of predation. Egg mortality due to flounder predation was estimated to average 5.0, 2.2, and 1.9% in 1978, 1979, and 1980, respectively. Egg mortality due to predation is believed to be significantly greater at deepwater demersal spawning sites and may have a significant impact on recruitment in demersal spawners. The average energy gain to winter flounder resulting from consumption of capelin eggs was estimated to contribute 23% of the annual growth of flounder in the region (approximate 95% confidence interval: 10–40%). Selective exploitation of capelin eggs by postspawning flounder may also contribute significantly to the rapid recovery of body condition following the extensive depletion of tissue resources due to winter fasting, gonad production, and spawning.

The Winter Flounder (Pseudopleuronectes americanus) in Long Pond, Conception Bay, Newfoundland

1971 ◽  
Vol 28 (8) ◽  
pp. 1153-1165 ◽  
Author(s):  
V. S. Kennedy ◽  
D. H. Steele
Keyword(s):  
Food Intake ◽  
Growth Rates ◽  
Plant Material ◽  
Early Growth ◽  
Winter Flounder ◽  
Pseudopleuronectes Americanus ◽  
Food Items ◽  
Fish Remains ◽  
Males And Females ◽  
Conception Bay

Monthly samples of winter flounder taken in Long Pond from November 1962 to October 1963 indicated that the flounder moved into deeper water (7–10 m) during the summer and returned to shallow water (1–2 m) from September to June. These movements corresponded to the end of the spawning season and the ripening of the gonads respectively. Spawning occurred from March until early June, most of it in May and early June. Most males were mature at age 6 and most females at age 7. Fifty percent of the males and females were mature at 21 and 25 cm respectively. The growth rates of the males and females were similar until the age of 8, after which the females apparently outgrew the males. Early growth and fecundity were similar to those reported for other areas. No feeding took place in December or January but the flounder fed in March and continued to feed throughout the summer; food intake decreased in the fall. They were omnivorous and the type of food eaten varied with the locality. Polychaetes, plant material, and molluscs were the most common food items throughout the year. Capelin eggs and fish remains were found only during a few months of the year but were eaten in great quantities.

Lack of genetic divergence in capelin (Mallotus villosus) spawning at beach versus subtidal habitats in coastal embayments of Newfoundland

2014 ◽  
Vol 92 (5) ◽  
pp. 377-382 ◽  
Author(s):  
Paulette M. Penton ◽  
Craig T. McFarlane ◽  
Erin K. Spice ◽  
Margaret F. Docker ◽  
Gail K. Davoren
Keyword(s):  
Local Adaptation ◽  
Genetic Divergence ◽  
Geographic Area ◽  
Mallotus Villosus ◽  
The North ◽  
Coastal Embayments ◽  
Fish Spawning ◽  
Capelin Mallotus Villosus ◽  
Unpredictable Environment ◽  
Spawning Sites

Capelin (Mallotus villosus (Müller, 1776)), a focal forage fish in the north Atlantic, spawn on both beach and demersal (deep-water) sites throughout their circumpolar distribution. Although these habitats rarely occur in close proximity, demersal spawning sites within 4 km of beach spawning sites (subtidal) have recently been discovered in two coastal embayments in Newfoundland, Canada. The physical environment differs considerably between beach and subtidal spawning sites, creating the potential for local adaptation and genetic divergence of capelin from the two habitats, but this has never been investigated on a fine spatial scale. We use eight microsatellite loci to test for genetic divergence between capelin spawning at beach and subtidal sites within these two coastal regions in Newfoundland. We found no genetic differentiation between fish spawning at beach and subtidal sites or between the two regions. The results from this fine-scale study are in agreement with the lack of habitat-based structure reported in other studies examining beach and demersal sites separated by a larger geographic area. We suggest that instead of showing site fidelity and local adaptation, the facultative use of alternate spawning habitats may be a more successful strategy in an unpredictable environment.

Effects of fish length and temperature on the timing of peak spawning in capelin (Mallotus villosus)

1997 ◽  
Vol 54 (4) ◽  
pp. 781-787 ◽  
Author(s):  
J Carscadden ◽  
B S Nakashima ◽  
K T Frank
Keyword(s):  
Adult Survival ◽  
Data Series ◽  
Fish Length ◽  
Mallotus Villosus ◽  
Sea Temperature ◽  
Capelin Mallotus Villosus ◽  
Spawning Time ◽  
Mature Fish ◽  
And Migration ◽  
Gonad Production

Some characteristics of Newfoundland capelin (Mallotus villosus) changed during 1991-1994. Peak spawning times were later than most years in the 1980s and fish were smaller. These changes occurred during a period of below-normal sea temperatures. We tested the effects of sea temperatures during maturation and mean size of mature fish on peak spawning times using regression analysis and found significant negative relationships for both independent variables. Results of a stepwise regression showed that fish length and sea temperature during maturation were equally important and together explained about 80% of the spawning time variation. We suggest that maturation and migration are closely linked to seasonal warming and the zooplankton cycle. Given the high spawning mortality of capelin, it seems that this linkage favours maximum gonad production rather than adult survival. Knowledge of spring water temperatures would permit some prediction of capelin spawning time. However, the data series for mean length used in this analysis is not useful for predicting spawning time.

Predation on winter flounder (Pseudopleuronectes americanus) eggs by the sand shrimp (Crangon septemspinosa)

2005 ◽  
Vol 62 (7) ◽  
pp. 1611-1625 ◽  
Author(s):  
David L Taylor ◽  
Donald J Danila
Keyword(s):  
Deterministic Model ◽  
Size Structure ◽  
Early Stage ◽  
Winter Flounder ◽  
Spawning Season ◽  
Effect Of Temperature ◽  
Feeding Rates ◽  
Pseudopleuronectes Americanus ◽  
Egg Mortality ◽  
Crangon Septemspinosa

This study estimated rates of sand shrimp (Crangon septemspinosa) predation on winter flounder (Pseudopleuronectes americanus) eggs and examined the effect of temperature on density-dependent mortality of early-stage flounder. In laboratory experiments, shrimp feeding rates on flounder eggs were positively correlated with temperature and shrimp size. Immunological assays of shrimp stomach contents indicated that 7.2% of shrimp collected from the Niantic River (Connecticut) had flounder eggs in their stomachs. Incidence of egg predation was highest in February (20%) and decreased continuously into early April (1.2%). In a deterministic model simulating predator-induced mortality of flounder eggs during a spawning season, shrimp consumed 0.4%–49.7% of the total flounder spawn. Variations in shrimp population abundance and size structure accounted for the greatest variability in egg mortality. Water temperature during the spawning season presumably alters the population dynamics of early-stage flounder. In a long-term survey, the number of yolk-sac flounder larvae in warm years (≥4.3 °C) was depressed at high egg densities, indicating strong compensatory processes that increased egg mortality and limited the abundance of larvae. Failure of flounder to produce strong year-classes of larvae during warm years, possibly resulting from altered trophic dynamics, may explain the inability of stocks to recover from previous overexploitation.

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.

Patterns of larval emergence of capelin (Mallotus villosus) and environmental cues at demersal spawning sites on the northeastern coast of Newfoundland

2008 ◽  
Vol 65 (6) ◽  
pp. 1135-1143 ◽  
Author(s):  
Paulette M. Penton ◽  
Gail K. Davoren
Keyword(s):  
Water Column ◽  
Good Condition ◽  
Larval Survival ◽  
Mallotus Villosus ◽  
Capelin Mallotus Villosus ◽  
Warm Surface Water ◽  
Larval Emergence ◽  
Wind Events ◽  
Northeastern Coast ◽  
Spawning Sites

At spawning beaches in Newfoundland, Canada, capelin ( Mallotus villosus ) larval emergence is triggered by coastal water mass replacement (CWMR). CWMR causes sharp but short increases in temperature in coastal areas by the transport of warm surface water to the coast during onshore wind events. Warm water temperatures stimulate the active emergence of capelin larvae into predator-poor and prey-rich conditions favourable for larval survival. We investigated whether wind events influenced (i) the thermal properties of the water column and (ii) the larval emergence patterns at five demersal (deep-water) spawning sites on the northeastern coast of Newfoundland during the posthatch periods in 2004–2006. Winds oriented along the shore caused frequent and sharp increases in bottom temperature at all sites but did not appear to stimulate the release of larvae into the water column. Instead, peaks in larval densities corresponded to predicted peaks in hatching. Because of this and the presence of recently hatched larvae (3–5 mm) primarily in good condition, we hypothesize that larvae simply emerged from the sediment upon hatching at these demersal spawning sites. We conclude that patterns of larval emergence at demersal sites in this region are different from those reported for the beach in other regions of Newfoundland.

scholarly journals Spatial and temporal patterns of capelin (Mallotus villosus) spawning sites in the Barents Sea

2021 ◽  
Vol 244 ◽  
pp. 106117
Author(s):  
Salah Alrabeei ◽  
Sam Subbey ◽  
Sofie Gundersen ◽  
Harald Gjøsæter
Keyword(s):  
Barents Sea ◽  
Temporal Patterns ◽  
Spatial And Temporal Patterns ◽  
Mallotus Villosus ◽  
The Barents Sea ◽  
Capelin Mallotus Villosus ◽  
Spawning Sites
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