Seasonal and diel variations of various blood parameters in Atlantic cod (Gadus morhua) and American plaice (Hippoglossoides platessoides)

1993 ◽  
Vol 71 (3) ◽  
pp. 611-618 ◽  
Author(s):  
Céline Audet ◽  
Michel Besner ◽  
Jean Munro ◽  
Jean-Denis Dutil
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Plasma Osmolality ◽  
Blood Parameters ◽  
Time Of Day ◽  
Seasonal Effect ◽  
Lawrence Estuary ◽  
Blood Hemoglobin ◽  
Diel Variations ◽  
Hippoglossoides Platessoides

Seasonal and diel variations of different blood variables were studied in Atlantic cod (Gadus morhua) and American plaice (Hippoglossoides platessoides) subjected to natural fluctuations of salinity and temperature in the St. Lawrence estuary. Significant seasonal fluctuations were found for all the parameters measured (plasma osmolality, Na+, Cl−, K+, glucose, Cortisol, and blood hemoglobin and hematocrit). In cod, the seasonal effect on blood hemoglobin was only detected through its interaction with time of day. In this species, all parameters also varied on an hourly basis, although these changes only represented a small proportion of the variance explained by the statistical model. In plaice, only plasma osmotic composition and blood hematocrit did not show diel variations, while the hour effect was difficult to characterize. In general, though our results indicate that both species acclimated to test conditions, American plaice seemed to cope less efficiently than Atlantic cod with winter conditions. In this respect, the Atlantic cod represents a better candidate for coastal aquaculture in this area.

Seasonal variation in the habitat associations of Atlantic cod (Gadus morhua) and American plaice (Hippoglossoides platessoides) from the southern Gulf of St. Lawrence

1998 ◽  
Vol 55 (12) ◽  
pp. 2548-2561 ◽  
Author(s):  
D P Swain ◽  
G A Chouinard ◽  
R Morin ◽  
K F Drinkwater
Keyword(s):  
Seasonal Variation ◽  
Habitat Selection ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Statistical Significance ◽  
Habitat Associations ◽  
Practical Implications ◽  
Hippoglossoides Platessoides ◽  
Trawl Surveys ◽  
Selection Of

We compared habitat associations of southern Gulf of St. Lawrence Atlantic cod (Gadus morhua) and American plaice (Hippoglossoides platessoides) between the summer feeding season on the Magdalen Shallows and the overwintering period in the Cabot Strait. Data were from bottom trawl surveys conducted in September 1993, 1994, and 1995 and January 1994, 1995, and 1996. Both species occupied much deeper, warmer water in winter than in summer. The effect of cod age on temperature distribution reversed between the two seasons, with younger cod occupying warmer water than older cod in summer and colder water in winter. Selection of both depth and temperature by cod tended to be more significant in September than in January. The reduced statistical significance of habitat selection by cod in winter was associated with a more aggregated distribution in this season. The contrast between seasons in habitat associations was particularly strong for plaice. The median habitats occupied by plaice were 58-67 m and -0.1 to 0.3°C in September and 374-426 m and 5.2-5.4°C in January. Habitat selection by plaice was significant in both seasons, but significance tended to be greater in January. Degree of aggregation in plaice distribution was similar between the two seasons. Female plaice occupied significantly warmer water than males in September but not in January. The ecological and practical implications of this striking seasonal variation in habitat associations are discussed.

Protein Instability in Minced Flesh from Fillets and Frames of Several Commercial Atlantic Fishes During Storage at −5 C

1975 ◽  
Vol 32 (6) ◽  
pp. 775-783 ◽  
Author(s):  
J. R. Dingle ◽  
J. A. Hines
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Protein Solubility ◽  
Kidney Tissue ◽  
Rapid Loss ◽  
Atlantic Mackerel ◽  
Trimethylamine Oxide ◽  
Minced Fish ◽  
Protein Instability ◽  
Hippoglossoides Platessoides

Minced flesh of Atlantic cod (Gadus morhua) and pollock (Pollachius virens), recovered by means of meat-separator machines from frames left after filleting operations, suffered a rapid loss of protein solubility during storage at −5 C. This was due to the presence of kidney tissue which caused the formation of dimethylamine and formaldehyde from the trimethylamine oxide of the muscle. The minced flesh of witch flounder (Glyptocephalus cynoglossus), American plaice (Hippoglossoides platessoides), and Atlantic mackerel (Scomber scombrus) was relatively stable when mixed with homogenates of their own kidney tissue, but cod kidney caused the same changes in gray sole as it did in minced cod flesh. The exclusion of gadoid kidney and blood from minced fish preparations is recommended.

Changes in arterial PO2, physiological blood parameters and intracellular antioxidants in free-swimming Atlantic cod (Gadus morhua) exposed to varying levels of hyperoxia

2010 ◽  
Vol 37 (1) ◽  
pp. 249-258 ◽  
Author(s):  
Anders Karlsson ◽  
Lene Sørlie Heier ◽  
Bjørn Olav Rosseland ◽  
Brit Salbu ◽  
Anders Kiessling
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Blood Parameters ◽  
Free Swimming ◽  
Arterial Po2

Arsenic Concentrations in Some Coexisting Marine Organisms from Newfoundland and Labrador

1976 ◽  
Vol 33 (6) ◽  
pp. 1388-1393 ◽  
Author(s):  
Victor S. Kennedy
Keyword(s):  
Newfoundland And Labrador ◽  
Gadus Morhua ◽  
Carapace Length ◽  
Sea Water ◽  
Atlantic Cod ◽  
Negative Relationship ◽  
Inorganic Arsenic ◽  
Fish Muscle ◽  
Reinhardtius Hippoglossoides ◽  
Hippoglossoides Platessoides

Inorganic arsenic concentrations in sea water and mud, and total arsenic concentrations in bodies of shrimp, zooplankton, and fish from northern Newfoundland and southern Labrador were measured. There was a positive relationship between concentration and carapace length in Pandalus borealis and P. montagui and a negative relationship in Eualus macilentus. There was no relationship between concentrations in shrimp eggs and carapace length. Arsenic concentrations in zooplankton and fish muscle were relatively low compared with the shrimp species; amphipods contained more arsenic than copepods or euphausiids, and American plaice (Hippoglossoides platessoides) more than redfish (Sebastes marinus), turbot (Reinhardtius hippoglossoides), and Atlantic cod (Gadus morhua). There was no evidence of increasing arsenic concentrations through successively higher levels of the food chain.

Rates of Digestion of Different Prey in Atlantic Cod (Gadus morhua), Ocean Pout (Macrozoarces americanus), Winter Flounder (Pseudopleuronectes americanus), and American Plaice (Hippoglossoides platessoides)

1982 ◽  
Vol 39 (5) ◽  
pp. 651-659 ◽  
Author(s):  
J. Stevenson Macdonald ◽  
Kenneth G. Waiwood ◽  
Roger H. Green
Keyword(s):  
Goodness Of Fit ◽  
Gadus Morhua ◽  
Prey Species ◽  
Atlantic Cod ◽  
Graphical Analysis ◽  
Winter Flounder ◽  
Pseudopleuronectes Americanus ◽  
Evaluation Procedures ◽  
Visual Index ◽  
Hippoglossoides Platessoides

Stomachs of ocean pout (Macrozoarces americanus), Atlantic cod (Gadus morhua), winter flounder (Pseudopleuronectes americanus), and American plaice (Hippoglossoides platessoides) were removed and dissected 5, 12, 20, and 30 h after the fish had fed voluntarily to test the evacuation rates of three different prey species. Two evaluation procedures were used: a visual index of recognizabiiity, and a graphical analysis of percent of each prey recovered versus time since feeding. Three decay models were tested for goodness of fit to the evacuation data. The polychaete worms were the first to become unrecognizable, followed by amphipods. These species showed significantly different rates of evacuation when compared with the bivalves which were recognizable for the longest time. The exponential decay curve gave the best overall fit to the data. However, a linear model gave a good or better fit to the decay rate of the bivalve. The evacuation rates of different prey should be considered in estimating daily rations of fish in their environment.Key words: digestion, stomach content, food organism, Yoldia sapotilla, Tmetonyx cicada, Nephtys incisa

scholarly journals Status and biology of harbour seals (Phoca vitulina) in Svalbard

2010 ◽  
Vol 8 ◽  
pp. 47 ◽  
Author(s):  
Christian Lydersen ◽  
Kit M Kovacs
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Growth Curves ◽  
Reproductive Rate ◽  
Time Of Day ◽  
Small Population ◽  
Polar Cod ◽  
Adult Males ◽  
Adult Females ◽  
Harbour Seals

Harbour seals in Svalbard are the northernmost population of this species. This small population is comprised of ca. 1,000 individuals, most of which reside along the west coast of Prins Karls Forland (78°20’N). Satellite tracking studies have shown that adults are resident. Birthing occurs in the latter half of June. Newborns weigh about 11 kg and gain an average of 0.7 kg/d during the nursing period. Haulout patterns in Svalbard harbour seals are influenced by date (season), time of day, tidal cycle and temperature. Moulting takes place in early fall, first among juveniles, then in adult females and finally in adult males. Feeding studies show that polar cod (Boreogadus saida) is the dominant prey in terms of numbers, while Atlantic cod (Gadus morhua) is the dominant prey based on biomass, at least during the early autumn. Growth curves display significant sexual dimorphism with asymptotic values for standard length and body mass being greater formales. Testosterone levels inmales showed an abrupt increase at 6 years of age, while estradiol levels in females increased abruptly from age 4 years. The reproductive rate for adult females was 0.93. Longevity of Svalbard harbour seals is very short compared with populations from other areas.

Geographical variations in abundance of larval anisakine nematodes in Atlantic cod (Gadus morhua) and American plaice (Hippoglossoides platessoides) from the Gulf of St. Lawrence

1995 ◽  
Vol 52 (S1) ◽  
pp. 105-115 ◽  
Author(s):  
France Boily ◽  
David J. Marcogliese
Keyword(s):  
Nova Scotia ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Temporal Variations ◽  
Anisakis Simplex ◽  
Geographical Variations ◽  
Pseudoterranova Decipiens ◽  
Hippoglossoides Platessoides

Atlantic cod (Gadus morhua) and American plaice (Hippoglossoides platessoides) collected from various sites in the Gulf of St. Lawrence (NAFO divisions 4RST) were examined for larval anisakine nematodes in 1990 and 1992. Sealworm larvae (Pseudoterranova decipiens) were more abundant in southern Gulf (4T) than in northern Gulf (4RS) cod and plaice. The heaviest sealworm infections occurred in fish from St. Georges Bay, Nova Scotia. Abundance of P. decipiens in cod from St. Georges Bay was significantly lower in 1992 than in 1990. Anisakis simplex and Contracaecinea (Contracaecum/Phocascaris spp.) were most abundant in cod from the northern Gulf. American plaice were not heavily infected with A. simplex or Contracaecinea. Geographical and temporal variations in abundance of larval anisakine nematodes in fish may reflect distribution and abundance of the phocid and cetacean definitive hosts and variations in water temperatures.

Sex-specific temperature distribution of American plaice (Hippoglossoides platessoides) and its relation to age and abundance

1997 ◽  
Vol 54 (5) ◽  
pp. 1077-1087 ◽  
Author(s):  
D P Swain
Keyword(s):  
Temperature Distribution ◽  
Gadus Morhua ◽  
Annual Variation ◽  
Atlantic Cod ◽  
Cold Temperatures ◽  
Fitness Benefits ◽  
Specific Temperature ◽  
The Difference ◽  
Using Data ◽  
Hippoglossoides Platessoides

I examined variation in the temperature distribution of American plaice (Hippoglossoides platessoides) in the southern Gulf of St. Lawrence using data from bottom trawl surveys conducted each September since 1971. Plaice tended to select cold temperatures relative to those available. Temperature distribution was unrelated to age over the range 3-12+ years. Females tended to occupy warmer water than males, although the extent of this difference between the sexes varied among years. Annual variation in plaice temperature distribution was positively correlated with variation in the temperatures available. After accounting for annual variation in available temperatures, female temperature distribution was density independent but males tended to occupy colder water at higher levels of abundance. The median temperature occupied by both sexes tended to be warmer at higher levels of abundance of Atlantic cod (Gadus morhua), a competitor of plaice. The difference between the sexes in temperature distribution increased as cod abundance decreased or as plaice abundance increased (depending on the measure of temperature distribution used). The observed difference between the sexes in temperature distribution and its density dependence may reflect differences in foraging rate associated with differences between the sexes in the fitness benefits of growth.

Effects of release parameters on recovery rates of tagged groundfish species

1999 ◽  
Vol 56 (10) ◽  
pp. 1732-1751 ◽  
Author(s):  
G M Fowler ◽  
W T Stobo
Keyword(s):  
Gadus Morhua ◽  
Atlantic Cod ◽  
Melanogrammus Aeglefinus ◽  
Fish Length ◽  
Significant Determinant ◽  
Coastal Regions ◽  
Recovery Rates ◽  
Haddock Melanogrammus Aeglefinus ◽  
Hippoglossoides Platessoides ◽  
Over Time

A compilation of groundfish mark-recapture studies conducted in the Northwest Atlantic from 1953 to 1985 was examined by analysis of deviance to determine the effects of release parameters on subsequent recoveries of Atlantic cod (Gadus morhua), haddock (Melanogrammus aeglefinus), pollock (Pollachius virens), and American plaice (Hippoglossoides platessoides). Fish length was a major determinant of recoveries for all four species, with recovery rates generally increasing with increasing fish length. Depth of capture was a significant determinant of recoveries for cod and haddock, with recovery rates decreasing as depth increased. Year of release was a significant determinant for all four species, with recovery rates declining in recent years. Declines in recovery rates of cod, haddock, and pollock occurred during certain months or seasons. Recovery rates decreased where fish were tagged in areas most distant from inhabited coastal regions, but the interpretation of this effect is complicated by changes in the fisheries over time between areas. Recovery rates also decreased with increasing catch size and varied between different tag types and capture methods. The results should prove useful in the design of tagging protocols and analysis of recovery data.

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