Behavioural, physiological and morphological adaptations of the shanny (<i>Blennius pholis</i>) to the intertidal habitat

Abstract

Immersed shannies ( Blennius pholis ) showed peak locomotory activity coincident with daylight high tides. Emersion caused cessation of breathing and bradycardia though Q 0 2 was little affected. Q 0 2 fell, however, when the abdomen was enclosed in an impermeable sheath to block cutaneous respiration. Gulping of air into the extensively vascular oesophagus probably also acts as a means of aerial respiration. Reimmersion of fish caused a transient bradycardia followed by a tachycardia and a fall in Q 0 2 followed subsequently by a rise. The results are discussed in relation to the behavioural, circulatory, respiratory and morphological adaptations of the shanny to the intertidal habitat.