Plathelminths in tropical intertidal sediments of northeastern Australia

Abstract

Assemblages of free-living interstitial plathelminths are described from the tropical coast of northeast-ern Australia. About one hundred species were recorded from sediments of mangroves, tidal flats, and seagrass beds. The majority (88%) of the plathelminths occurred in only one habitat. Richest in spe-cies were Kalyptorhynchia (39), followed by Acoela (17) and Typhloplanoida (16). Over 50% of the species found were represented by one to three individuals, but a few species were frequently encoun-tered. The preferred habitat was sand with 86% of all species, while abundances were higher in muddy sediments. The mean species density was 7 in 10 cm-2 of sediment, and abundances ranged from 8 to 52 individuals 10 cm-2 with an average plathelminth abundance of 25 individuals 10 cmP2. Predatory plathelminths were predominant with up to 77% of the individuals. A comparison is made to plathel-minth assemblages in temperate tidal flats. Introduction Here, I present data on composition and dis-tribution of assemblages of plathelminth species Free-living plathelminths are a worldwide com-in tropical intertidal habitats, their patterns of ponent of marine meiofaunal communities (Mar-abundance, and their use of microhabitats. This tens & Schockaert, 1986). They are well studied is the first publication on the ecology of