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

(1) Gas exchange water and in air of the intertidal cirriped Pollicipes polymerus has been studied by combined field and laboratory experiments. (2) Haemolymph gas tensions and pH are correlated with the tidal cycle in the field. Air exposure is accompanied by increasing O Sub(2) and CO Sub(2) 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. (3) The O Sub(2) uptake of Pollicipes is higher for air exposed than for submerged animals at each tested temp. In air exposed animals the O Sub(2) uptake shows a decreasing Q Sub(10) with increasing temp between 2 and 27{degree}C. Pollicipes exhibits O Sub(2) conformity under varying ambient O Sub(2) tensions and no O Sub(2) debt is found after exposure to hypoxic water. (4) The peduncle cuticle is permeable to O Sub(2) and cutaneous respiration at this level may contribute significantly to the overall O Sub(2) uptake. (5) Pollicipes is well adapted to respiratory gas exchange both in water and in air making it a successful sp in the intertidal community.