Bl. Bayne, Relations between variable rates of growth, metabolic costs and growth efficiencies in individual Sydney rock oysters (Saccostrea commercialis), J EXP MAR B, 251(2), 2000, pp. 185-203
Citations number
52
Categorie Soggetti
Aquatic Sciences
Journal title
JOURNAL OF EXPERIMENTAL MARINE BIOLOGY AND ECOLOGY
Rock oysters from a mass selection trial were compared with wild-caught (co
ntrol) oysters of the same age to determine the physiological basis for fas
ter growth rates amongst the selected individuals, and to describe the asso
ciated flexibility in phenotypic traits of feeding, metabolism and growth.
In confirmation of earlier studies, fast growth was associated with faster
rates of feeding, reduced metabolic rates and lower metabolic costs of grow
th. Selected individuals deposited more protein, at a lower metabolic cost,
than the controls. Control oysters, however, deposited more lipid than the
selected oysters, though the unit costs of lipid deposition did not differ
between categories. The results indicated a wide plasticity of physiologic
al rates and efficiencies and demonstrated how, by selection, interactions
between physiological traits can serve to enhance growth. If differences in
lipid deposition observed here were indicative of different rates of gamet
ogenesis, then the results also suggest that selection alters the balance b
etween growth and reproduction. Whether these differences can be termed com
pensatory with respect to the life history of the species remains to be det
ermined, but the results indicate some of the ways in which physiological f
lexibility may be expressed to effect different patterns of energy allocati
on. (C) 2000 Elsevier Science B.V. All rights reserved.