Allometric growth and condition factor of Atlantic cod (Gadus morhua) fed to satiation: effects of temperature and body weight

Abstract Nephrops was found to be of low quality as food for cod. In a laboratory experiment the mean specific growth rate of 1 kg cod was 0.184 and 0.415% d−1 when fed to satiation on Nephrops and capelin, respectively. This large difference in growth rate resulted not only from less intake of Nephrops (1.19 kg cod−1) than capelin (1.55 kg cod−1) but also because more Nephrops (4.6 kg) than capelin (2.2 kg) were required to produce each kilogramme of cod. Higher food conversion ratio was consistent with lower fat content of Nephrops (1.3%) than capelin (9.2%) but the exoskeleton also reduced the digestion rate of Nephrops. In the groups where Nephrops and capelin of equal mean weight were offered simultaneously, 40% of the diet consisted of Nephrops during the first week and 10% during the final seven weeks of the experiment. At the end of the experiment, condition factor, liver index, and gonadosomatic index were significantly lower for cod fed on Nephrops (0.967, 5.7, 7.1, respectively) than for those fed on capelin (1.086, 15.8, 11.2, respectively). These results suggests that predation by cod on Nephrops might be reduced by regular release of capelin or other similar food in the distributional areas of Nephrops.

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Anaesthesia of Atlantic cod (Gadus morhua) — Effect of pre-anaesthetic sedation, and importance of body weight, temperature and stress

Aquaculture ◽

10.1016/j.aquaculture.2009.06.019 ◽

2009 ◽

Vol 295 (1-2) ◽

pp. 52-59 ◽

Cited By ~ 63

Author(s):

Inger Hilde Zahl ◽

Anders Kiessling ◽

Ole Bent Samuelsen ◽

Magne Kjerulf Hansen

Keyword(s):

Body Weight ◽

Gadus Morhua ◽

Atlantic Cod

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Effects of temperature and salinity on comparative embryo development and mortality of Atlantic cod (Gadus morhua L.) and haddock (Melanogrammus aeglefinus (L.))

ICES Journal of Marine Science ◽

10.1093/icesjms/36.3.220 ◽

1976 ◽

Vol 36 (3) ◽

pp. 220-228 ◽

Cited By ~ 59

Author(s):

G. C. Laurence ◽

C. A. Rogers

Keyword(s):

Embryo Development ◽

Gadus Morhua ◽

Atlantic Cod ◽

Melanogrammus Aeglefinus ◽

Effects Of Temperature ◽

Haddock Melanogrammus Aeglefinus

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The Effects of Temperature on Feeding and Expression of Two Appetite-related Factors, Neuropeptide Y and Cocaine- and Amphetamine-regulated Transcript, in Atlantic Cod,Gadus morhua

Journal of the World Aquaculture Society ◽

10.1111/j.1749-7345.2008.00215.x ◽

2008 ◽

Vol 39 (6) ◽

pp. 790-796 ◽

Cited By ~ 19

Author(s):

A. S. Kehoe ◽

H. Volkoff

Keyword(s):

Neuropeptide Y ◽

Gadus Morhua ◽

Atlantic Cod ◽

Related Factors ◽

Effects Of Temperature

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Sperm competition and fertilization success in Atlantic cod (Gadus morhua): effect of sire size and condition factor on gamete quality

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f99-164 ◽

1999 ◽

Vol 56 (12) ◽

pp. 2315-2323 ◽

Cited By ~ 53

Author(s):

Ana Rakitin ◽

Moira M Ferguson ◽

Edward A Trippel

Keyword(s):

Body Size ◽

Sperm Competition ◽

Gadus Morhua ◽

Condition Factor ◽

Atlantic Cod ◽

Sperm Quality ◽

Fertilization Success ◽

Male Body ◽

Single Female ◽

Male Condition

Sperm competition experiments were conducted to test the null hypothesis that sperm quality is not affected by male body size in Atlantic cod (Gadus morhua). Genetic markers (allozymes) were used to determine the proportion of larvae sired by pairs of males when their sperm was combined with eggs of a single female simultaneously. Significant differences in fertilization success between males were not explained by differences in body size. Fertilization success was positively associated with male condition factor (K) and with spermatozoa density in each male's semen when equal volumes of semen from each male were used. Male K was positively associated with male fertilization success when the volume of semen used from each male was adjusted to add approximately equal numbers of spermatozoa from each male. The relative fertilization success of males varied depending on which female was the egg donor, suggesting that female "choice" at the gamete level may be occurring in cod.

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