Differences in physiological energetics between intertidal and raft cultivated mussels Mytilus galloprovincialis

Methods of physiological energetics were applied to compare growth rates of mussels Mytilus galloprovincialis Lmk from 2 habitats: intertidal and raft cultures.Scope for growth was determined after l and 15 d under standard laboratory conditions Both groups of mussels improved their growth potential during maintenance in the laboratory due to a combination of increased ingestion rate and decreased metabol~c rate.Cultivated mussels presented h ~g h e r weight-specific clearance rates, higher absorption efficiency and higher rates of ammonia excretion, w h ~c h resulted in increased scope for growth with respect to ~ntertldal mussels.This finding is related to the differential characteristics of these 2 habitats in terms of cycles of food availability and air exposure.Differences between the groups of mussels persisted after 15 d of experimental treatment and were mainly accounted for by absorption efficiency.