Hanging on in there - Position maintenance by the high-shore rockpool harpacticoid copepod Tigriopus brevicornis

The high-shore rockpool habitat of Tigriopus brevicornis is subject to considerable physical disturbance from high spring tides and storms and hence the species must deal with the potential hazard of being swept out. Scanning electron microscopy, video image analysis and flow-through chamber experimentation was used to study the micro-morphology and behaviour of T. brevicornis to understand the position maintenance capabilities of the species. Micro-serrations and forward-facing claws on the first swimming leg combined with hooks on the caudal furcae appear to be the major morphological structures used in position maintenance. Morphological comparisons are made with the subtidal sand-dwelling harpacticoid Harpacticus flexus. The ability of T. brevicornis to burrow into loose sediment is also discussed.