Optimum temperature for growth in the catarina scallop (Argopecten ventricosus-circularis, Sowerby II, 1842)

In an attempt to determine temperature optimum for growth in juvenile (10.0 -11.8 mm mean shell height) catarina scallop Argopecten ventricosus-circula ris, scope for activity, ingestion and clearance rates, irrigation efficien cy, and growth were investigated between 12 and 28 degrees C. The animals w ere acclimated at the same temperature as the assays. Results indicate that scope for activity (the arithmetic difference between active and standard respiration rates) increased from 12 degrees C to a maximum at 19 degrees C , and then declined to 28 degrees C. Mean ingestion rates (IR) were higher at 19 and 22 degrees C and lower at 16, 25, and 28 degrees C. Clearance rat e (CR) was also higher at 19 and 22 degrees C, and lower at 16, 25, and 28 degrees C. No statistical difference (P > .01) of IR and CR was obtained be tween 19 and 22 degrees C. irrigation efficiency (liters of water filtered per mi O-2 consumed) followed the same trend as the scope for activity, wit h a maximum at 19 DC. The highest growth rate was at 19 degrees C in a 54-d ay experiment. All these results indicate the temperature optimum for the j uvenile catarina scallop population studied was between 19 and 22 degrees C .