Distribution and feeding of epibenthic holothuroids on the reef flat of Laing Island (Papua New Guinea)

Abstract

ABSTRACT: Among the 7 most abundant species of holothuroids found on the east reet flat of Laing Island (Papua New Guinea), Holothuria atra and Holothuria leucospilota represented more than 90 % of the total number of individuals observed. Hydrodynamics was the most important factor regulating the distribution of the species studied kpple-marks and reduced sand were factors restricting holothuroid dstribution. No relation was found between body size of the epibenthic holothuroids and particle-size classes of the gut sediment. Tentacular structures were not related to the size of particles ingested. Some holothuroids seem to physically select ingested sediment, while others do not. The behaviour of the population of one species is affected by the habitat and by the presence of other species. The partitioning of ingested sediment allows ecologically similar species to coexist.