GLYCOGEN DEPLETION DURING STARVATION IN THE NEMERTEAN, MICRURA LEIDYI (VERRILL), AND ITS ECOLOGICAL SIGNIFICANCE

¹ Monmouth College, Monmouth, Illinois, and The Marine Biological Laboratory, Woods Hole, Mass.

1. Micrura leidyi maintains a glycogen store of 1.83 per cent of the wet weight of the worm after 16 to 35 days of aerobic starvation. Specimens removed directly from the ocean had 1.57 per cent glycogen. The ability of an organism to reserve glycogen for use under anaerobic conditions is a possible adaptive mechanism which has not previously been reported.

2. The glycogen level decreased from 1.57 per cent to 1.49 per cent after 24 hours and was further reduced to 0.29 per cent after 72 hours of anaerobiosis.

3. M. leidyi is relatively resistant to conditions of complete anaerobiosis. The maximum survival time in the present experiments was seven days.

4. Seven specimens starved aerobically for 16 to 35 days lost an average of 10 per cent of their original body weight.