n terms of microhabitat, the majority of species are infaunal (70%), but a substantial portion also occurs as epifauna (18%) and about 12% of species occur as both (http://www.nt.gov.au/nreta/museums/magnt/collectionsresearch/naturalsciences/annelids.html). Most species avoided the sediment surface, the exceptions being the large nereidid Paraleonnates bolus and the phyllodocid Phyllodoce sp., which mostly was collected in pitfall traps. Epifaunal species mostly occurred under the bark of mangrove trees, but also in fallen timber. Particularly productive microhabitats were beneath the large flakes of bark on the lower trunks of Sonneratia alba in the seaward assemblage and within rotting, burrow-structured roots and limbs of Rhizophora stylosa in the tidal creek assemblage. Certain species including Lepidonotus sp. 1, Neanthes cf. biseriata and Perinereis singaporiensis were almost exclusively sampled from the trunks of Sonneratia alba.