Continuous Recording of Arterial Blood in Octopus Vulgaris During Progressive Hypoxia and Movement

The respiratory and acid-base status of the blood of animals continually changes in response to variations in internal and external conditions. Attempts to monitor transitory changes by repetitive sampling techniques can, however, lead to an unacceptable level of blood loss. An external circulatory shunt in which blood is continuously removed from one vessel, passed across monitoring electrodes and reintroduced into an appropriate second vessel would obviate this problem. Such a system has been developed to continuously monitor blood gas parameters and pH in fish (Belaud, Trotter & Peyraud, 1979; Thomas & Le Ruz, 1982). The present study attempts to apply a similar technique to an invertebrate, Octopus vulgaris.