Sipuncula associated with branching fire coral (millepora alcicornis) in a marine protected area in northeastern Brazil

Abstract

Most hard substrata, such as corals, are colonized by burrowing or encrusting organisms. Sipunculid worms are commonly observed burrowing in calcareous substrata, especially in coral skeletons or dead sections of living corals. The objective of the present study was to identify and quantify species of sipunculid worms associated with beds of branching fire coral (Millepora alcicornis) in a marine protected area of Rio Grande do Norte, Brazil. The selected colonies were wrapped in plastic bags to avoid loss of associated fauna and then detached from the substratum with a hammer and chisel. Samples were fixed in 4% formalin during 24 hours. In the laboratory each colony was carefully fragmented the sipunculids were removed without causing damage to their structure. The specimens retreated were preserved in 70% alcohol. A total of 38 specimens were found from 11 colonies. The sipunculids belonged to 4 species and 3 families and the density ranged from 1 to 17 individuals/dm3 . Sipunculid worms contribute actively to the erosion in organisms with calcareous skeletons making them brittle