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Alunno-bruscia, Marianne; Petraitis, P; Bourget, E; Frechette, Marcel. |
We grew mussels (Mytilus edulis) under two different food regimes and eight population density levels to estimate the joint effects of density and biomass on their growth and survival and to determine the shape of the biomass-density (B-IV) relationship. Mussels were reared for 22 months, between December 1994 and October 1996, in 1-L experimental chambers supplied with natural seston. Growth in shell length, individual wet mass and ash free dry mass (m) decreased with decreasing food availability and increasing population density. Survival was negatively correlated with density but did not differ significantly between food regimes during the first year. Variations in concentration of available food did not alter the effects of crowding on mussels, as... |
Tipo: Text |
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Ano: 2000 |
URL: http://archimer.ifremer.fr/doc/2000/publication-6791.pdf |
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Alunno-bruscia, Marianne; Bourget, Edwin; Frechette, Marcel. |
We examined the influence of food availability and population density on the morphometry and shell length body mass relationship of Mytilus edulis. Mussels were reared in the laboratory for 22 mo at 8 different density levels in 11 chambers supplied with natural seston at 2 different concentrations. This allowed us to assess separately the effects of food availability and mussel density. The shell length/width and shell height/width ratios were affected by food, density and time. Mussels tended to be narrower (flatter) at high density and at low food level. Therefore, narrow shells could result from reduced food concentration in high density situations without implying physical interference. Shell mass was also influenced by both food and density levels,... |
Tipo: Text |
Palavras-chave: M N curve; Length mass density relationship; Food regulation; Shell allometry; Mussels. |
Ano: 2001 |
URL: http://archimer.ifremer.fr/doc/2001/publication-807.pdf |
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Frechette, Marcel; Goulletquer, Philippe; Daigle, Gaétan. |
Japanese cupped oysters suffer summer mortality in many culture sites along the French Atlantic coast. To ascertain whether mortality might be associated with morphological features of the shells, we estimated fluctuating asymmetry (FA) of hatchery/nursery-produced oysters kept in culture bags in the intertidal. FA is defined as random variations from a perfect symmetry plane (bilateral or radial) in some morphological trait. FA increases with disruption of homeostasy during ontogeny and has both genetic and environmental determinants. We found significant differences in FA between dead and live oysters in two of our three study groups. Therefore, lack of developmental stability may be involved in the summer mortality syndrome of oysters. We also found... |
Tipo: Text |
Palavras-chave: Oyster; Mortality; Fluctuating asymmetry; Aquaculture. |
Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/publication-575.pdf |
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