BURROWING MACROINFAUNA IN MOUNDS OF THALASSINA ANOMALA (HERBST) (THALASSINIDEA, CRUSTACEA) IN SOME SINGAPORE MANGROVES

Abstract

The mounds created by the mud lobster Thalassina anomala (Herbst.) plays an important ecological role in the mangrove system in ameliorating conditions for other organisms. Periodic tidal inundation over the mounds results in a vertical distribution of fauna reminescent of intertidal distributions over a rocky shore. Distribution parameters - tide inundation and mangrove soil type - were first determined. Two burrowers, Wolffogebia phuketensis sp.nov. Sakai and Annina n.sp. were examined, relating their habit and burrow systems to distribution. Wolffogebia phuketensis, a filter-feeder, inhabited U-tube burrow systems and are normally found in the lower reaches of the mounds receiving inundation daily. Annina n.sp. is an omnivorous sporadic scavenger found inhabiting simple 'free-form' burrows. Peak abundance occurs around mid-mound region, receiving inundation only during spring tides. Other burrowing infauna such as some mangrove hymenopterans, are also given brief mention.