Thread-like tentacles in the Mediterranean corals Paramuricea clavata and Corallium rubrum

Abstract

The occurrence of modified tentacles (i.e. thread-like tentacles) in the Mediterranean octocorals Paramuricea clavata and Corallium rubrum is reported. Colonies of four species of Mediterranean gorgonians were maintained in aquarium conditions for more than five months. The development of thread-like tentacles was observed only in two of the four species. The presence of modified tentacles in other cnidarians has usually been associated with defensive/aggressive behaviour. Our observations show that threadlike tentacles in P. clavata and C. rubrum can also be used for feeding.