QUANTIFICATION OF THE PHYSIOLOGICAL RESPONSES OF THE EUROPEAN FLAT OYSTER OSTREA EDULIS L. TO TEMPERATURE AND SALINITY

• Published in: Journal of molluscan studies 1992-05, Vol.58 (2), p.215-226
• Main Authors: HUTCHINSON, S., HAWKINS, L.E.
• Format: Article
• Language: English
• Subjects: Animal and plant ecology; Animal, plant and microbial ecology; Animals; Autoecology; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Invertebrates; Protozoa. Invertebrata
• ISSN: 0260-1230; 1464-3766
• DOI: 10.1093/mollus/58.2.215

Physiological stress was quantified in specimens of the European flat oyster Ostrea edulis, acclimated to a matrix of temperature (5–25°C) and salinity (16–34%o) conditions, using the Scope for Growth (SFG) index. Variations in the index were interpreted from the responses of its components, absorption efficiency, filtration rate, respiration and ammonia excretion rates, to external conditions. Mean SFG values were most influenced by acclimation temperature but significant differences were found between animals at different salinities over the range tested. There was a severe reduction in SFG when high temperature was combined with reduced salinity (≦19%o) and a less severe, but still marked, diminution in SFG was also observed when animals were subjected to low temperatures and reduced salinity. The responses at the extremes of the temperature and salinity ranges may be interpreted as differential and synergistic effects of the two environmental variables on the components of the SFG index. The laboratory studies can be related to observations of O. edulis in the field.