Opercular differential pressure as a predictor of metabolic oxygen demand in the starry flounder

Abstract

The feasibility of using a differential pressure sensor connected to an acoustic telemetry device to monitor opercular activity as a correlate of oxygen consumption was investigated. Four starry flounders Platichthys stellatus were fitted with a miniature differential pressure sensor mounted close to the operculum. A cannula was connected to the sensor and inserted under the operculum, inside the branchial cavity. Measurements of oxygen consumption and opercular activity were carried out over a broad range of metabolic activity, from the post‐surgery stress (high metabolic rate) to routine metabolic rate the following day. Relationships between differential pressure changes (rate and amplitude) were highly correlated with oxygen consumption ( r 2 = 0·74 and 0·60 respectively). The results indicate that monitoring opercular activity offers an alternative method for measuring aerobic metabolism in free‐swimming fishes in nature.