Diets supplemented with seaweed affect metabolic rate, innate immune, and antioxidant responses, but not individual growth rate in European seabass (Dicentrarchus labrax)

The estuarine amphipod Gammarus lawrencianus was subjected to prolonged selection (3 years; 26 generations) for high population growth rates. The demography of the selected population was studied in detail and compared under laboratory conditions with animals derived from a control (wild) population collected in the same area 3 years later. In the lab-adapted population the intrinsic rate of population growth r increased by 72% as the result of changes in age at maturation, survivorship, and fecundity. The variance of these traits decreased and Crow's (1958) index of total selection (variance of fitness/mean fitness squared) is proposed as a quantitative and operational measure of genetic adaptation to a changed environment. Possible limitations on adaptation were investigated by examining the correlations among demographic traits within the lab-adapted population. Some phenotypic correlations were determined directly and others by an indirect technique using information from full siblings. Individual growth rate was negatively correlated both with survival and fecundity. Individual growth rate and age at sexual maturity were also negatively correlated. Negative phenotypic correlations between traits may indicate limitations on long-term adaptation. We conclude that significant evolutionary changes in the demographic traits of this (and presumably other) marine crustacean can occur within a time scale of interest to ecologists and aquaculturalists.Key words: adaptation, amphipod, aquaculture, Crustacea, evolution, Gammarus, genetics, life history, strategy

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Evaluating the possible feeding strategies of selenium nanoparticles on the growth rate and wellbeing of European seabass (Dicentrarchus labrax)

Aquaculture Reports ◽

10.1016/j.aqrep.2020.100539 ◽

2020 ◽

Vol 18 ◽

pp. 100539

Author(s):

Marwa F. Abd El-Kader ◽

Ahmed. F. Fath El-Bab ◽

Moustafa Shoukry ◽

Abdel-Wahab A. Abdel-Warith ◽

Elsayed M. Younis ◽

...

Keyword(s):

Growth Rate ◽

Dicentrarchus Labrax ◽

Selenium Nanoparticles ◽

Feeding Strategies ◽

European Seabass

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Is boldness towards predators related to growth rate in naïve captive-reared Arctic char (Salvelinus alpinus)?

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f07-041 ◽

2007 ◽

Vol 64 (4) ◽

pp. 665-671 ◽

Cited By ~ 10

Author(s):

Mika VM Laakkonen ◽

Heikki Hirvonen

Keyword(s):

Growth Rate ◽

Captive Breeding ◽

Salvelinus Alpinus ◽

Antipredator Behavior ◽

Underlying Mechanism ◽

Arctic Char ◽

Individual Growth ◽

Detailed Knowledge ◽

Individual Growth Rate ◽

Slow Growing

Previous studies have shown that the antipredator responsiveness of fish degenerates through generations in captive breeding. However, detailed knowledge of the underlying mechanism is still largely lacking. We tested the hypothesis that hatchery fish supposedly selected for faster growth in the hatchery environment are bolder towards predators than their slower-growing conspecifics. This was examined by comparing the antipredator behavior of predator- naïve fast- and slow-growing individuals of a captive-bred Arctic char (Salvelinus alpinus) population to chemical cues from natural predators burbot (Lota lota) and pikeperch (Sander lucioperca). As behavioral responses depended on char body size, we compared boldness towards predators of size-matched fast- and slow-growing char. We found no differences in four behavioral antipredator traits between size-matched groups of fast- and slow-growing char. According to these results, boldness to predator cues is not related to individual growth rate in captive-bred Arctic char.

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Variation in intrinsic individual growth rate among populations of leatherside chub (Snyderichthys copei Jordan & Gilbert): adaptation to temperature or length of growing season?

Ecology Of Freshwater Fish ◽

10.1111/j.1600-0633.2005.00091.x ◽

2005 ◽

Vol 14 (2) ◽

pp. 177-184 ◽

Cited By ~ 16

Author(s):

M. C. Belk ◽

J. B. Johnson ◽

K. W. Wilson ◽

M. E. Smith ◽

D. D. Houston

Keyword(s):

Growth Rate ◽

Growing Season ◽

Individual Growth ◽

Individual Growth Rate ◽

Leatherside Chub

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

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f99-088 ◽

1999 ◽

Vol 56 (9) ◽

pp. 1612-1623 ◽

Cited By ~ 43

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.

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