A Comparative Study of the Respiratory Metabolism in Porcellio laevis (Lat.) and Armadillidium vulgare (Lat.): Response to Temperature, Photoperiod and Oxygen Concentration

Abstract

Relationship of body weight, imposed fasting, temperature, fight intensity, and oxygen concentration to oxygen consumption in Porcellio laevis and Armadillidium vulgare has been investigated in a series of laboratory experiments. It was observed that (1) the metabolic response in the two species to temperature change was a uniform increase of oxygen consumption with increasing temperature from 15°C to 30 °C. Beyond 30 °C, the oxygen consumption in each species fell, and the thermal death point was reached at about 40 °C. (2) The response to decreasing oxygen concentrations was a corresponding decrease in oxygen consumption. Armadillidium vulgare was a partial regulator while Porcellio laevis was able to conform its internal state to the changing oxygen levels. (3) In each species there was a decrease in metabolic rate with increasing body weight. (4) On the basis of their general activity level and oxygen consumption rate, Porcellio appeared to be a nocturnal species, while Armadillidium had a day active metabolism.