TUBE-DWELLING MEIOFAUNA IN MARINE-SEDIMENTS

Tube-dwelling has been recognized previously as a life-style for sever al meiobenthic species, but behavioural observation of living specimen s has rarely been reported. The extent to which tube-building and tube -dwelling occurs within meiofauna, and how they have influenced evolut ionary and ecological processes as well as morphology within these org anisms, is relatively unknown but potentially of great significance. I n addition to direct observation of tube-building and the occurence of tubes in natural habitats, the internal anatomy associated with tube- building in two nematode species (Ptycholaimellus jacobi, P. ponticus) and one harpacticoid copepod species (Stenhelia palustris) is the foc us of this study. Special attention is given to the secretory products , glands, and their association with secretory pores. Also, the role o f meiobenthic tube-dwelling activities in relationship to their enviro nment is extensive discussed.