Brown, A.C.

Demonstrates that sand moisture is a factor determining the depth of burrowing in the isopod Tylos granulatus Krauss. Role of grain size and stratification; Inability of the animals to burrow in totally dry sand. Tylos granulatus, a sandy-beach isopod, prefers an environmental moisture range exceeding 3,4% but less than 13%. The depths to which the animals burrow are, at least partly, determined by the moisture gradient in the sand. They are, however, incapable of burrowing into totally dry sand. Animals alter their position in the sand in response to changes in moisture content so as to ensure exposure to suitable conditions.