Peer Review #3 of "Copepods enhance nutritional status, growth and development in Atlantic cod (Gadus morhua L.) larvae — can we identify the underlying factors? (v0.1)"

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

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Peer Review #2 of "Iodine nutrition and toxicity in Atlantic cod (Gadus morhua) larvae (v0.1)"

10.7287/peerj.20v0.1/reviews/2 ◽

2013 ◽

Keyword(s):

Peer Review ◽

Gadus Morhua ◽

Atlantic Cod ◽

Iodine Nutrition

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Peer Review #1 of "Iodine nutrition and toxicity in Atlantic cod (Gadus morhua) larvae (v0.1)"

10.7287/peerj.20v0.1/reviews/1 ◽

2013 ◽

Author(s):

K PITTMAN

Keyword(s):

Peer Review ◽

Gadus Morhua ◽

Atlantic Cod ◽

Iodine Nutrition

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The growing degree-day and fish size-at-age: the overlooked metric

Canadian Journal of Fisheries and Aquatic Sciences ◽

10.1139/f07-003 ◽

2007 ◽

Vol 64 (2) ◽

pp. 375-385 ◽

Cited By ~ 165

Author(s):

Anna B Neuheimer ◽

Christopher T Taggart

Keyword(s):

Growth And Development ◽

Gadus Morhua ◽

Atlantic Cod ◽

Variable Temperature ◽

Spatial Scales ◽

Explanatory Power ◽

Field Studies ◽

Fish Length ◽

Degree Day ◽

Size At Age

Growth rate in ectotherms, including most fish, is a function of temperature. For decades, agriculturalists (270+ years) and entomologists (45+ years) have recognized the thermal integral, known as the growing degree-day (GDD, °C·day), to be a reliable predictor of growth and development. Fish and fisheries researchers have yet to widely acknowledge the power of the GDD in explaining growth and development among fishes. We demonstrate that fish length-at-day (LaD), in most cases prior to maturation, is a strong linear function of the GDD metric that can explain >92% of the variation in LaD among 41 data sets representing nine fish species drawn from marine and freshwater environments, temperate and tropical climes, constant and variable temperature regimes, and laboratory and field studies. The GDD demonstrates explanatory power across large spatial scales, e.g., 93% of the variation in LaD for age-2 to -4 Atlantic cod (Gadus morhua) across their entire range (17 stocks) is explained by one simple GDD function. Moreover, GDD can explain much of the variation in fish egg development time and in aquatic invertebrate (crab) size-at-age. Our analysis extends the well-established and physiologically relevant GDD metric to fish where, relative to conventional time-based methods, it provides greater explanatory power.

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Impacts of regular and random noise on the behaviour, growth and development of larval Atlantic cod ( Gadus morhua )

Proceedings of The Royal Society B Biological Sciences ◽

10.1098/rspb.2015.1943 ◽

2015 ◽

Vol 282 (1817) ◽

pp. 20151943 ◽

Cited By ~ 33

Author(s):

Sophie L. Nedelec ◽

Stephen D. Simpson ◽

Erica L. Morley ◽

Brendan Nedelec ◽

Andrew N. Radford

Keyword(s):

Growth And Development ◽

Gadus Morhua ◽

Atlantic Cod ◽

Acoustic Noise ◽

Random Noise ◽

Mitigation Measures ◽

Lower Body ◽

Body Width ◽

Sound Levels

Anthropogenic noise impacts behaviour and physiology in many species, but responses could change with repeat exposures. As repeat exposures can vary in regularity, identifying regimes with less impact is important for regulation. We use a 16-day split-brood experiment to compare effects of regular and random acoustic noise (playbacks of recordings of ships), relative to ambient-noise controls, on behaviour, growth and development of larval Atlantic cod ( Gadus morhua ). Short-term noise caused startle responses in newly hatched fish, irrespective of rearing noise. Two days of both regular and random noise regimes reduced growth, while regular noise led to faster yolk sac use. After 16 days, growth in all three sound treatments converged, although fish exposed to regular noise had lower body width–length ratios. Larvae with lower body width–length ratios were easier to catch in a predator-avoidance experiment. Our results demonstrate that the timing of acoustic disturbances can impact survival-related measures during development. Much current work focuses on sound levels, but future studies should consider the role of noise regularity and its importance for noise management and mitigation measures.

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