RESPIRATION AND ANAEROBIC SURVIVAL IN SOME SEA WEED-INHABITING INVERTEBRATES

¹ Dept. of Zoology, Univ. of Vienna, Austria, and Woods Hole Oceanographic Institution, Woods Hole, Massachusetts

1. The water trapped by large brown sea weeds at low tide may become oxygen-free in the night or on cloudy days.

2. Slow-moving, non-swimming animals living in the sea weeds all the time (like nematodes and mites) are paralyzed by the removal of oxygen from the water, but they recover from this state if the period of anaerobic stress has lasted less than approximately 16 hours at 25° C. The relationship between time of anaerobiosis and time of recovery is temperature-dependent and a characteristic of each of the three species investigated (Enoplus communis, Rhombognathides seahami, Halacarus basteri basteri).

3. Agile animals, capable of leaving and repopulating the sea weeds with the tides, show a different reaction pattern. One of the amphipods investigated (Calliopius laeviusculus) did not survive even a few minutes of anaerobiosis, while the other two species (Gammarus oceanicus, Hyale prevosti) survived from about half an hour to three hours of anaerobiosis. The former species occasionally leads a pelagic life and has twice the respiratory rate of the latter two species.