Production of antifreeze glycoproteins in cultured and wild juvenile Atlantic cod (<i>Gadus morhua</i> L.) in a common laboratory environment

Many fishes accumulate antifreeze proteins or antifreeze glycoproteins (AFGPs) in the blood to increase their chances of survival in cold seawater. Cod (Gadus morhua L.) from colder environments have been found to produce more AFGPs than those from warmer areas, but the genetic and environmental contributions to this variation have not been determined. Populations of cultured (from the Grand Banks; Gulf of Maine) and wild (from Fortune Bay; Bonavista Bay) juvenile cod were kept in a common laboratory environment to investigate differences in AFGP production. All the populations were capable of producing AFGPs, and the AFGP levels were similar in cultured and wild cod. The results indicate that high temperatures associated with the production of cultured cod do not negatively affect the ability to produce AFGPs. In addition, young cod from as far south as the Gulf of Maine are capable of producing AFGPs at levels similar to those from the northeast coast of Newfoundland.

Download Full-text

Seasonal changes in the plasma levels of glycoprotein antifreeze, Na+, Cl−, and glucose in Newfoundland Atlantic cod (Gadus morhua)

Canadian Journal of Zoology ◽

10.1139/z82-240 ◽

1982 ◽

Vol 60 (8) ◽

pp. 1851-1854 ◽

Cited By ~ 20

Author(s):

G. L. Fletcher ◽

D. Slaughter ◽

C. L. Hew

Keyword(s):

Seasonal Changes ◽

Gadus Morhua ◽

Thermal Hysteresis ◽

Atlantic Cod ◽

Freezing Point ◽

Freezing Point Depression ◽

Antifreeze Glycoproteins ◽

Glucose Levels ◽

Total Plasma Protein ◽

Two Peaks

A seasonal study was carried out on the hematocrits, plasma freezing point depression, and thermal hysteresis, and plasma Na+, Cl−, total protein, and glucose concentrations in laboratory maintained Atlantic cod. Significant thermal hysteresis was evident in the plasma during the months of January to May indicating the presence of antifreeze glycoproteins. Plasma freezing point depression and Na+ and Cl− concentrations were highest during the winter months and lowest during the summer. Two peaks in glucose levels were evident; one in February and the other in July. No seasonal changes were evident in hematocrits and total plasma protein concentrations.

Download Full-text

Antifreeze glycoproteins in the plasma of Newfoundland Atlantic cod (Gadus morhua)

Canadian Journal of Zoology ◽

10.1139/z81-296 ◽

1981 ◽

Vol 59 (11) ◽

pp. 2186-2192 ◽

Cited By ~ 34

Author(s):

Choy L. Hew ◽

Don Slaughter ◽

Garth L. Fletcher ◽

Shashikant B. Joshi

Keyword(s):

Amino Acid ◽

High Performance ◽

Gadus Morhua ◽

Atlantic Cod ◽

Antifreeze Proteins ◽

Gel Filtration ◽

Exchange Chromatography ◽

Polar Cod ◽

Antifreeze Glycoproteins ◽

Molecular Weights

The plasma of the Atlantic cod, Gadus morhua, contained antifreeze glycoproteins which were present only during the winter months. The antifreeze proteins were isolated, using gel filtration and ion exchange chromatography, and characterized by high performance liquid chromatography. The antifreeze proteins appeared to consist of at least seven components with molecular weights ranging from 2 500 to 33 000. Chemical analysis of the larger components showed a predominance of alanine, threonine, and galactosamine in a ratio of 2:1:1. The smaller peptides contained proline, in addition to alanine and threonine. The amino acid sequence of the smallest glycopeptide (molecular weight 2500) was found to be Ala Ala Thr Pro Ala Thr Ala Ala Thr Pro Ala Thr Ala Ala.These glycoproteins are very similar, if not identical, in amino acid and carbohydrate composition to those isolated from Antaractic nototheniids and several northern gadoids. The sequence of the smallest glycopeptide from the Atlantic cod is identical to that reported for the polar cod, Boreogadus saida.

Download Full-text

Overwintering of Adult Northern Atlantic Cod (Gadus morhua) in Cold Inshore Waters as Evidenced by Plasma Antifreeze Glycoprotein Levels

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f94-282 ◽

1994 ◽

Vol 51 (12) ◽

pp. 2834-2842 ◽

Cited By ~ 23

Author(s):

Sally V. Goddard ◽

J. S. Wroblewski ◽

C. T. Taggart ◽

K. A. Howse ◽

W. L. Bailey ◽

...

Keyword(s):

Gadus Morhua ◽

Atlantic Cod ◽

Antifreeze Glycoproteins ◽

Cold Temperatures ◽

Antifreeze Glycoprotein ◽

Trap Fishery ◽

In The Wild ◽

History Of ◽

Inshore Waters ◽

Trinity Bay

Adult Atlantic cod (Gadus morhua) are known to produce antifreeze glycoproteins in response to cold temperatures. Our laboratory studies demonstrated that blood plasma levels in adult cod were positively correlated with the number of days they spent in subzero water. Between April 1991 and June 1993, we monitored concentrations of antifreeze glycoproteins in the plasma of late juvenile and adult cod in Trinity Bay, Newfoundland, and used the results to estimate how long cod had been exposed to low water temperatures. A consideration of these data in conjunction with detailed temperature profiles of the area taken over the course of the study allowed us to deduce the distribution of cod in relation to the temperature field. This study provides evidence that (1) blood antifreeze glycoprotein levels can be used to deduce the recent thermal history of cod in the wild and (2) after their inshore summer feeding period, considerable numbers of adult cod overwintered inshore in Trinity Bay in subzero water, producing antifreeze glycoproteins as temperatures fell below 0 °C. From May onwards, "cold-adapted" cod moved into warming surface waters, where they became available to an early inshore trap fishery.

Download Full-text

Low temperature regulation of antifreeze glycopeptide levels in Atlantic cod (Gadus morhua)

Canadian Journal of Zoology ◽

10.1139/z87-037 ◽

1987 ◽

Vol 65 (2) ◽

pp. 227-233 ◽

Cited By ~ 32

Author(s):

Garth L. Fletcher ◽

Madonna J. King ◽

Ming H. Kao

Keyword(s):

Low Temperature ◽

Gadus Morhua ◽

Cold Water ◽

Atlantic Cod ◽

Continuous Light ◽

Half Time ◽

Antifreeze Glycoproteins ◽

Long Day ◽

Biological Half Time ◽

Influence Of Water

The influence of water temperature and photoperiod on the timing of the annual cycle of plasma antifreeze glycoproteins (AFGP) was examined in Atlantic cod. Long day lengths (18 h) or continuous light had no effect on the time of appearance or disappearance of AFGP from the plasma. Cold water (0 °C) advanced the time of AFGP appearance by as much as 100 days. Long day lengths had no effect on this early induction of AFGP production. AFGP was not detectable in the plasma of fish exposed to water temperatures greater than 1 °C. Although small amounts of AFGP did appear in the plasma of cod exposed to 1 °C, it immediately began to disappear while plasma levels in normal and 0 °C acclimated cod continued to rise. The biological half time of AFGP activity was very sensitive to temperature, ranging from 15.6 days at 5 °C to 99.4 days at 0 °C. The results of this study suggest that the appearance of AFGP in cod during the winter months is dependent on the cod's exposure to water temperatures at least as low as 1 °C. Although 1 °C appears to be capable of initiating production of AFGP, it is not low enough to allow normal protective levels to be built up in the plasma.

Download Full-text

Antifreeze Production, Freeze Resistance, and Overwintering of Juvenile Northern Atlantic Cod (Gadus morhua)

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f92-061 ◽

1992 ◽

Vol 49 (3) ◽

pp. 516-522 ◽

Cited By ~ 37

Author(s):

Sally V. Goddard ◽

Ming H. Kao ◽

Garth L. Fletcher

Keyword(s):

Gadus Morhua ◽

Atlantic Cod ◽

Fish Length ◽

Antifreeze Glycoproteins ◽

Freeze Resistance ◽

Ambient Temperatures ◽

Temperature Regimes ◽

Northern Atlantic ◽

Freezing Temperatures ◽

Cycling Temperature

Four size groups of northern Atlantic cod (Gadus morhua) (juveniles < 15, 15–25, and 26–40 cm and adults > 50 cm) were investigated over a winter cycle for their ability to increase freeze resistance by producing plasma antifreeze glycoproteins. All juveniles had significantly higher plasma antifreeze levels than adults during the winter (January–March) under similar conditions of cycling temperature and ambient photoperiod. Highest winter plasma antifreeze levels and lowest plasma freezing temperatures were consistently found in the 15–25 cm group. Fish length and plasma antifreeze levels were inversely related from January to April, with the exception of the 0 + cod. All juvenile groups developed considerable freeze protection early in the winter cycle before the onset of freezing temperatures. However, the adults were not significantly protected until the end of January, when ambient temperatures had fallen below 0 °C. The 15–25 cm cod were held in three cycling temperature regimes. Induction temperatures for antifreeze production in this size group appeared to be between 2 and 3 °C, as compared with between 1 and 0 °C for the adults. We suggest that these patterns of antifreeze production may have direct bearing on habitat selection and overwintering behaviour of the northern Atlantic cod at different stages of development.

Download Full-text