Abstract

The hydraulic activities of two arenicolid polychaetes, Abarenicola pacifica and Arenicola marina, result in strikingly similar pressure waveforms. The principal hydraulic activities are defecation, burrowing and feeding/burrow maintenance. Both the duration and magnitudes of the pressures are very similar. The behavioral periodicities of the two species are also quite similar, although burrowing is more common in A. pacifica than in A. marina. Additionally burrowing activities in A. marina appear to be more influenced by tidal stage than those in A. pacifica. The link between burrowing and pore-water pressure reductions makes this difference potentially important in terms of drawing oxygenated water into surface sediments