scholarly journals How should enzyme activities be used in fish growth studies?

1995 ◽  
Vol 198 (7) ◽  
pp. 1493-1497 ◽  
Author(s):  
D Pelletier ◽  
P Blier ◽  
JD Dutil ◽  
H Guderley
Keyword(s):  
Growth Rate ◽  
Gadus Morhua ◽  
White Muscle ◽  
Citrate Synthase ◽  
Atlantic Cod ◽  
Muscle Protein ◽  
Dry Mass ◽  
Fish Growth ◽  
Individual Growth ◽  
Oxidative Enzymes

The activity of glycolytic and oxidative enzymes was monitored in the white muscle of Atlantic cod Gadus morhua experiencing different growth rates. A strong positive relationship between the activity of two glycolytic enzymes and individual growth rate was observed regardless of whether the enzyme activity was expressed as units per gram wet mass, units per gram dry mass or with respect to muscle protein and DNA content. The most sensitive response to growth rate was observed when pyruvate kinase and lactate dehydrogenase activities were expressed as units per microgram DNA, and this may be useful as an indicator of growth rate in wild fish. In contrast, no relationship between the activities of oxidative enzymes and growth rate was observed when cytochrome c oxidase and citrate synthase activities were expressed as units per gram protein. Apparently, the aerobic capacity of white muscle in cod is not specifically increased to match growth rate.

Influence of growth and survival costs of reproduction on Atlantic cod, Gadus morhua, population growth rate

1999 ◽  
Vol 56 (9) ◽  
pp. 1612-1623 ◽  
Author(s):  
Jeffrey A Hutchings
Keyword(s):  
Growth Rate ◽  
Population Growth ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Environmental Stochasticity ◽  
Individual Growth ◽  
Growth And Survival ◽  
Individual Growth Rate ◽  
Age Structured ◽  
Reproductive Rates

A stochastic, age-structured life history model was used to examine how age at maturity (theta), pre- (Zimm) and postreproductive (Zmat) mortality, and postreproductive growth rate can affect maximum reproductive rates of fish at low population size. Simulations suggest that annual (r) and per-generation (R0) metrics of population growth for Newfoundland's northern Grand Bank Atlantic cod, Gadus morhua, are primarily influenced by changes to mortality prior to and following reproduction. At observed weights at age and Zmat = 0.2, r ranged between 0.135 and 0.164 for cod maturing at between 4 and 7 years. Incremental increases in either Zimm or Zmat of 0.1 were associated with 0.03-0.05 reductions in r. To effect similar reductions, individual growth rate would have to decline by approximately one half. At observed weights at age, increases in Zmat from 0.20 to 0.45 increased the probability of negative per-generation growth from 3 to 26% for cod maturing at 4 years and from 6 to 46% for cod maturing at 7 years. Thus, even in the absence of fishing mortality, little or no population growth by Atlantic cod may not be unexpected in the presence of environmental stochasticity, particularly when accompanied by increases in mortality and declining individual growth.

Biochemical correlates of growth and condition in juvenile Atlantic cod (Gadus morhua) from Newfoundland

1998 ◽  
Vol 55 (7) ◽  
pp. 1591-1598 ◽  
Author(s):  
Patrice Couture ◽  
Jean-Denis Dutil ◽  
Helga Guderley
Keyword(s):  
Growth Rate ◽  
Water Content ◽  
Gadus Morhua ◽  
Citrate Synthase ◽  
Atlantic Cod ◽  
Nucleoside Diphosphate Kinase ◽  
Multiple Regression Model ◽  
Hepatosomatic Index ◽  
In The Wild ◽  
Muscle Water

The aim of this study was to examine how the biochemical composition of tissues varied with growth rate and condition in juvenile Atlantic cod (Gadus morhua) caught in the wild and kept in captivity. The hepatosomatic index, brain water content, and muscle sarcoplasmic protein content as well as the activities of phosphofructokinase, lactate dehydrogenase, nucleoside diphosphate kinase, and citrate synthase in the muscle, nucleoside diphosphate kinase and citrate synthase in the intestine, and cytochrome c oxidase and citrate synthase in the brain increased with growth rate or condition factor. Conversely, liver and muscle water contents were lower in fish with a higher growth rate. A multiple regression model that included the hepatosomatic index, water content of muscle and brain, and citrate synthase activity in the intestine explained 79.7% of the variability of growth in mass under our conditions. A similar model, using liver water content instead of muscle water content, explained 82.5% of the variability of growth in length. These easy to measure variables may be used in fisheries management to estimate the growth rate of fish in the wild.

Effects of Nutritional Regime on Correlates of Growth Rate in Juvenile Atlantic Cod (Gadus morhua): Comparison of Morphological and Biochemical Measurements

1993 ◽  
Vol 50 (3) ◽  
pp. 502-512 ◽  
Author(s):  
A. R. Foster ◽  
D. F. Houlihan ◽  
S. I. Hall
Keyword(s):  
Growth Rate ◽  
Gadus Morhua ◽  
White Muscle ◽  
Atlantic Cod ◽  
Specific Activity ◽  
Short Term ◽  
Protein Ratio ◽  
Linear Relationships ◽  
Biochemical Measurements

The effects of both long-term (35 d of daily feeding, feeding every second day, or starvation) and short-term (up to 15 d of refeeding following starvation) nutritional regimes on morphological (tissue-somatic indices) and biochemical measurements (RNA concentration, RNA/protein ratio, RNA/DNA ratio, and cytochrome c oxidase activity (CCO)) were investigated for a variety of Atlantic cod (Gadus morhua) tissues. Liver-somatic index was the morphological index most sensitive to both the long- and short-term nutritional regimes. The majority of the tissue RNA measurements demonstrated positive linear relationships with growth rate, although stomach, intestine, and white muscle were the most sensitive tissues for all the treatments. Most of the tissues examined also showed positive linear relationships with growth rate, although stomach, intestine, and white muscle were the most sensitive tissues for all the treatments. Most of the tissues examined also showed positive linear relationships between CCO specific activity and long-term growth rate. However, tissue CCO specific activity was relatively insensitive to the short-term alterations in nutritional regime.

Growth Rates and Protein Turnover in Atlantic Cod,Gadus morhua

1988 ◽  
Vol 45 (6) ◽  
pp. 951-964 ◽  
Author(s):  
D. F. Houlihan ◽  
S. J. Hall ◽  
C. Gray ◽  
B. S. Noble
Keyword(s):  
Growth Rate ◽  
Weight Loss ◽  
Protein Synthesis ◽  
Growth Rates ◽  
Gadus Morhua ◽  
White Muscle ◽  
Atlantic Cod ◽  
Degradation Rates ◽  
Protein Synthesis And Degradation ◽  
Synthesis And Degradation

Atlantic cod, Gadus morhua, were maintained on different ration levels or starved to produce a variety of growth rates. The in vivo rates of protein synthesis and degradation were determined for the whole fish and various tissues. As ration level, and hence growth rates, increased, both whole-animal protein synthesis and degradation rates increased linearly; growth occurred because of the preponderance of synthesis over degradation. On average, a 300-g cod growing at 1.0%∙d−1synthesised 1.25 g of protein with 0.4 g of this protein remaining as growth. The proportion of total protein synthesis which was retained as growth increased with increasing growth rate; at a maximum growth rate of 2%∙d−1, over 40% of the protein synthesised was retained as growth. The ranking of the tissues in terms of fractional rates of protein synthesis was liver > gills > intestine > spleen > ventricle > stomach > gonads > white muscle. The white muscle, gills, liver, stomach, spleen, and ventricle all showed similar patterns of increased protein synthesis with increased growth rate. The white muscle has the highest efficiency of retention of protein and accounts for 40% of the total protein accretion per day. In starving fish there was a constant level of protein synthesis, irrespective of the rate of weight loss. However, degradation rates increased in the whole animal and in white muscle as the rate of weight loss increased.

The food-unlimited growth rate of Atlantic cod (Gadus morhua)

2002 ◽  
Vol 59 (3) ◽  
pp. 494-502 ◽  
Author(s):  
Björn Björnsson ◽  
Agnar Steinarsson
Keyword(s):  
Growth Rate ◽  
Laboratory Experiments ◽  
Gadus Morhua ◽  
Size Range ◽  
Atlantic Cod ◽  
Growth Curves ◽  
Fish Growth ◽  
Fish Weight ◽  
Different Temperatures ◽  
Unlimited Growth

Results from laboratory experiments showed that food-unlimited growth rate (G) of Atlantic cod (Gadus morhua) declined linearly with fish weight (W) on a log–log scale at six different temperatures: 2, 4, 7, 10, 13, and 16°C. The intercept (αi) and slope (βi) of these regressions increased linearly with temperature (T), implying that G = αi W βi, where αi = γ1 + δ1T and βi = γ2 + δ2T. Nonlinear fit of the four-parameter model showed that γ1 was not significantly different from 0, and thus the following three-parameter model is suggested for the food-unlimited growth rate of cod ranging in size from 2 to 5000 g at any temperature from 2 to 16°C: G = (0.5735T)W(–0.1934–0.02001T). The results indicate that temperature in this size range has a much greater effect on the growth rate of small juvenile cod than on that of larger cod. The model predicts that the optimal temperature for growth of cod decreases with increased size of fish, from 14.3°C for 50-g fish to 5.9°C for 5000-g fish. Growth curves were derived for cod at constant and seasonally variable temperatures. Weight-at-age was calculated for different temperatures.

scholarly journals Comparison of growth rate among different protein genotypes in Atlantic cod, Gadus morhua, under farmed conditions

2006 ◽  
Vol 63 (2) ◽  
pp. 235-245 ◽  
Author(s):  
K.E. Jørstad ◽  
Ø. Karlsen ◽  
T. Svåsand ◽  
H. Otterå
Keyword(s):  
Growth Rate ◽  
Gadus Morhua ◽  
White Muscle ◽  
Specific Growth ◽  
Atlantic Cod ◽  
The Past ◽  
Aquaculture Industry ◽  
A New Species ◽  
Growth Experiments ◽  
Selection Of

Abstract A major aim of the aquaculture industry in Norway is to develop sustainable farming of Atlantic cod, Gadus morhua L. A great deal of research, including farming trials and stock enhancement, has been performed on this species in Norway during the past two decades. The success of domestication of a new species depends on the genetic variability of the wild broodstock and the selection of appropriate genotypes for the farming environment. Growth experiments under farmed conditions, including genetic analyses, were started as early as 1983 after the breakthrough of cod juvenile production in mesocosm systems. At later stages (1988 and 1992 year classes), more detailed studies were conducted under farmed conditions. Based on individual tagging and genotyping (blood and white muscle biopsy sampling), estimates of growth performance (specific growth rate, SGR) of the various genotypes within six polymorphic protein loci were obtained. In general, the SGR in the two experiments varied through the year as a function of temperature and body size. In the 1988 year-class experiment, only a few statistically significant differences (ANOVA) were detected among genotypes, measured as mean weight and SGR. The 1992 year-class experiment included two different cod stocks, Northeast Arctic (NE) and Norwegian coastal (NC) cod, which were reared for about two years in the same net pen. Further, during this experiment, only a few genotypes exhibited significantly different growth within the NE group. No consistency was found in the variation with regard to protein loci investigated, growth periods studied, and relationship with temperature variation.

Relationships Between RNA–DNA Ratio, Prey Density, and Growth Rate in Atlantic Cod (Gadus morhua) Larvae

1979 ◽  
Vol 36 (12) ◽  
pp. 1497-1502 ◽  
Author(s):  
L. J. Buckley
Keyword(s):  
Growth Rate ◽  
Nutritional Status ◽  
Growth Rates ◽  
Prey Density ◽  
Gadus Morhua ◽  
Slow Growth ◽  
Atlantic Cod ◽  
Larval Fish ◽  
Dry Weight ◽  
Dna And Rna

The protein, DNA, and RNA content of larvae maintained at 1.0 plankter/mL increased at the rates of 9.3, 9.9, and 9.8% per day, respectively, for the 5 wk after hatching. Protein reserves of larvae held at 0 or 0.2 plankters/mL were depleted by 45 and 35%, respectively, prior to death 12–13 d after hatching. Starved larvae had similar protein concentrations (percent of dry weight), lower RNA concentrations, and higher DNA concentrations than fed larvae. Larvae held at higher plankton densities had higher RNA–DNA ratios and faster growth rates than larvae held at lower plankton densities. The RNA–DNA ratio was significantly correlated (P < 0.01) with the protein growth rate. The RNA–DNA ratio appears to be a useful index of nutritional status in larval Atlantic cod (Gadus morhua) and may be useful for determining if cod larvae were in a period of rapid or slow growth at the time of capture. Key words: RNA–DNA ratio, starvation, protein, nucleic acids, growth, larval fish, Atlantic cod

Thermoregulatory behaviour in cod: Is the thermal preference in free-ranging adult Atlantic cod affected by food abundance?

2019 ◽  
Vol 76 (9) ◽  
pp. 1515-1527 ◽  
Author(s):  
Björn Björnsson
Keyword(s):  
Growth Rate ◽  
Data Storage ◽  
Gadus Morhua ◽  
Cold Water ◽  
Atlantic Cod ◽  
Vertical Mixing ◽  
Metabolic Energy ◽  
Fat Reserves ◽  
Free Ranging ◽  
Thermoregulatory Behaviour

This study supports the hypothesis that well-fed cod (Gadus morhua) seek higher temperatures to increase growth rate, and poorly fed cod select lower temperatures to save metabolic energy. Depth and temperature of free-ranging adult cod (44–79 cm) were studied with data storage tags as part of a ranching project in an Icelandic fjord. Forage fish were regularly provided at four feeding stations where cod formed distinct “herds” (herd cod) that did not mingle much with the rest of the unconditioned cod in the fjord (wild cod). Several parameters (stomach fullness, liver index (fat reserves), condition factor, and growth rate) indicated that food intake was much greater in herd cod than in wild cod. In August, when the thermocline was well established, the herd cod remained in shallow (15–35 m) and warm water (8–10 °C), whereas the wild cod stayed in deep (80–90 m) and cold water (3–4 °C), but occasionally both groups explored depths and temperatures outside their preferred range. After vertical mixing in autumn when thermoregulation was not possible, the depth difference between the two groups decreased significantly.

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