FREE-LIVING MARINE WORMS
This heterogeneous assemblage of four phyla of unsegmented, marine worms - the Chaetognatha, Sipuncula, Echiura, Nemertea - shows how versatile a tubular body can be. Arrow worms hunt in the plankton, beard worms live around hydrothermal vents 9000 metres below the sea surface. Peanut worms and spoon worms burrow in mud and sand, and ribbon worms live beneath stones on the seabed. A fifth phylum of marine worms, the pognophorans or beard worms, that only live in water deeper than 100 metres and survive in dense aggregations around thermal vents on the floor of the Galapagos rift at a depth of 9000 metres, is not unfortunately represented in our collection.