Sand moisture as a factor determining depth of burrowing in the oniscid isopod Tylos granulatus Krauss

Abstract

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 lotally dry sand. Animals alter their position in the sand in response to changes in moisture content so as to ensure exposure to suitable conditions.