Growth Of Plaice Research Articles

Influence of Green Tides in Coastal Nursery Grounds on the Habitat Selection and Individual Performance of Juvenile Fish.

Coastal ecosystems, which provide numerous essential ecological functions for fish, are threatened by the proliferation of green macroalgae that significantly modify habitat conditions in intertidal areas. Understanding the influence of green tides on the nursery function of these ecosystems is essential to determine their potential effects on fish recruitment success. In this study, the influence of green tides on juvenile fish was examined in an intertidal sandy beach area, the Bay of Saint-Brieuc (Northwestern France), during two annual cycles of green tides with varying levels of intensity. The responses of three nursery-dependent fish species, the pelagic Sprattus sprattus (L.), the demersal Dicentrarchus labrax (L.) and the benthic Pleuronectes platessa L., were analysed to determine the effects of green tides according to species-specific habitat niche and behaviour. The responses to this perturbation were investigated based on habitat selection and a comparison of individual performance between a control and an impacted site. Several indices on different integrative scales were examined to evaluate these responses (antioxidant defence capacity, muscle total lipid, morphometric condition and growth). Based on these analyses, green tides affect juvenile fish differently according to macroalgal density and species-specific tolerance, which is linked to their capacity to move and to their distribution in the water column. A decreasing gradient of sensitivity was observed from benthic to demersal and pelagic fish species. At low densities of green macroalgae, the three species stayed at the impacted site and the growth of plaice was reduced. At medium macroalgal densities, plaice disappeared from the impacted site and the growth of sea bass and the muscle total lipid content of sprat were reduced. Finally, when high macroalgal densities were reached, none of the studied species were captured at the impacted site. Hence, sites affected by green tides are less favourable nursery grounds for all the studied species, with species-specific effects related to macroalgal density.

Metabolism, food consumption and growth of plaice ( Pleuronectes platessa) and flounder ( Platichthys flesus) in relation to fish size and temperature

Daily rates of oxygen consumption, food consumption and growth of plaice ( Pleuronectes platessa) and flounder ( Platichthys flesus) have been measured in the laboratory at various constant temperatures. Oxygen consumption was related to body weight of the fish as a power function, with a weight exponent of between 0.71 and 0.85. No significant effects of temperature or feeding on this exponent were found. Flounder showed a significantly higher metabolic rate and a higher temperature coefficient for metabolism than plaice. Maximum daily rates of food consumption and the weight increment of fish fed with excess rations of fresh mussel meat could also be related to fish weights by means of power functions. For plaice these exponents decreased from about 0.9 at low temperatures (2–6 C°) to about 0.7 at high temperatures (18–22°C). Such a temperature effect on the weight exponent indicates that small juvenile fish eat more and grow faster at higher temperatures than do large older fish, and that large fish do better at low temperatures. After scaling of daily food consumption and growth in proportion to metabolic weights of the fish (W 0.78), feeding and growth at different fish sizes and temperatures can be compared and temperature-growth rate models can be used for investigations of feeding in natural populations. Compared to plaice, young flounder ate more and grew faster at higher temperatures (> 14°C). This may partly explain the preference of flounder for the shallower parts of coastal areas and estuaries, where summer temperatures and food densities are higher. Energy budgets of young plaice and flounder fed with excess rations of mussel meat indicate that at least 29% of the food energy is used for metabolism while about 37% of the food energy is converted into growth. The net conversion efficiency was estimated at 0.45 for food and growth in units of ash-free dry weight, and at 0.53 for food and growth in energy units. Analysis of the energy budget showed that the assimilated physiologically useful food energy is divided almost equally over metabolism (42–47%) and growth (53–55%). It is suggested that flatfish spend relatively less energy in swimming and therefore convert more food energy into growth than (pelagic) roundfish.

Changes in growth of plaice Pleuronectes platessa L. and sole Solea solea (L.) in the North Sea

The changes in growth of plaice and sole between 1957 and 1988, as estimated from samples of the commercial fishery and pre-recruit surveys, were analysed in order to study possible density dependent effects. Indices of potentially competitive biomasses of plaice and sole, based on Lloyd's index of mean crowding, were estimated from the average spatial distribution of various age groups during the summer growing period and from the population age structure as estimated by virtual population analysis. Growth of all age groups of sole increased in the 1960s and was stable in the 1970s and 1980s. In plaice only age groups 1 to 3 showed a similar increase in the 1960s, whereas the growth of 1-year-old plaice tended to decrease in the 1980s. Growth did not show a negative correlation with mean crowding, except in age group 1 of plaice and in age group 3+ of sole. It is concluded that these negative correlations do not provide unequivocal evidence for density dependent growth in plaice and sole, since they could equally well be caused by parallel but unrelated trends in time of one or more other factors. The simultaneous increase in growth in the 1960s of age groups of sole and plaice in the southern North Sea, and the absence of such an increase in age groups in the central North Sea, suggests that food availability must have increased in the Southern North Sea. This inference is supported by several macrobenthos studies. Whether the reduced growth of 1-group plaice in the 1980s, when recruitment was well above the average level, is caused by density dependent growth or to a reduced food availability remains an open question.

Some observations on the effects of feeding frequency on the food intake and growth of plaice, Pleuronectes platessa L.

The segregation of plaice, Pleuronectes platessa, into groups of uniform size can be used to reduce the formation of size hierarchies, even under conditions of limited food supply. When access to food was limited the fish responded by becoming hyperphagic. This resulted in an increase in growth rate following an initial growth check. However, even after hyperphagic adaptation, intermittently fed fish grew at slower rates than those allowed more frequent access to food. Hyperphagia was accompanied by an increase in relative stomach weight and gastric capacity but did not affect fat storage and proximate chemical composition.

The Growth of Plaice in Laxey Bay (Isle of Man)

The Growth of Plaice in Laxey Bay (Isle of Man)

EXPERIMENTS ON THE EFFECTS OF LEAD ON THE GROWTH OF PLAICE (PLEURONECTES PLATESSA)1

Annals of Applied BiologyVolume 13, Issue 2 p. 168-176 EXPERIMENTS ON THE EFFECTS OF LEAD ON THE GROWTH OF PLAICE (PLEURONECTES PLATESSA)1 W. J. DILLING M.B., Ch.B., W. J. DILLING M.B., Ch.B. Department of Pharmacology, Liverpool UniversitySearch for more papers by this authorC. W. HEALEY M.B., Ch.B., C. W. HEALEY M.B., Ch.B. Department of Pharmacology, Liverpool UniversitySearch for more papers by this authorW. C. SMITH, W. C. SMITH Department of Pharmacology, Liverpool UniversitySearch for more papers by this author W. J. DILLING M.B., Ch.B., W. J. DILLING M.B., Ch.B. Department of Pharmacology, Liverpool UniversitySearch for more papers by this authorC. W. HEALEY M.B., Ch.B., C. W. HEALEY M.B., Ch.B. Department of Pharmacology, Liverpool UniversitySearch for more papers by this authorW. C. SMITH, W. C. SMITH Department of Pharmacology, Liverpool UniversitySearch for more papers by this author First published: May 1926 https://doi.org/10.1111/j.1744-7348.1926.tb04261.xCitations: 10 This investigation was undertaken on behalf of the Liverpool Cancer Research Committee. Director: Prof. W. Blair Bell of the University of Liverpool. AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Citing Literature Volume13, Issue2May 1926Pages 168-176 RelatedInformation