Observations on the burrows and burrowing behaviour of <i>Calocaris macandreae</i> (Crustacea: Decapoda: Thalassinoidea)

A description of the burrows of Calocaris macandreae has been compiled from three field studies on the west coast of Scotland. The burrow tunnel configuration is a diagnostic feature of this species. Typically, the burrow complex contains at least one three entrance system to the surface and is developed on two levels (a primary level at 98—187 mm below the sediment surface and a secondary level at 140—215 mm). All the tunnel junctions within a burrow complex are tripartite. Development in the secondary level produces circular tunnels. In all three study areas the density of Calocaris was low in comparison with results from deeper water. The burrowing behaviour is described and a preliminary study of oxygen tension within the occupied burrow showed little oxygen loss between primary level tunnels and the overlying water.