Eco-physiological studies of an intertidal crustacean, Pollicipes polymerus (Cirripedia, Lepadomorpha): aquatic and aerial respiration.

Abstract

ABSTRACT Gas exchange in water and in air of the intertidal cirriped Pollicipes polymerus has been studied by combined field and laboratory experiments. Haemolymph gas tensions and pH are correlated with the tidal cycle in the field. Air exposure is accompanied by increasing oxygen and carbon dioxide tensions, and by decreasing haemolymph pH. During resubmersion the respiratory parameters are restored to values typical of the submerged state. There is no accumulation of lactic acid during air exposure. The oxygen uptake of Pollicipes is higher for air exposed than for submerged animals at each tested temperature. In air exposed animals the oxygen uptake shows a decreasing Q10 with increasing temperature between 2 and 27°C. Pollicipes exhibits oxygen conformity under varying ambient oxygen tensions and no oxygen debt is found after exposure to hypoxic water. The peduncle cuticle is permeable to oxygen and cutaneous respiration at this level may contribute significantly to the overall oxygen uptake. Pollicipes is well adapted to respiratory gas exchange both in water and in air making it a successful species in the intertidal community.