ABSTRACT: 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 1 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 metabolic rate. Cultivated mussels presented higher weight-specific clearance rates, higher absorption efficiency and higher rates of ammonia excretion, which resulted in increased scope for growth with respect to intertidal 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.

KEY WORDS: Mussel · Physiological energetics · Clearance rate · Metabolic rate · Absorption efficiency · Ammonia excretion rate · Scope for growth (SFG) · Net growth efficiency (K₂)

Published in MEPS Vol. 152 (1997) on June 26
ISSN: 0171-8630. Copyright © Inter-Research, Oldendorf/Luhe, 1997