ON THE FINDING OF A MASS OCCURRENCE OF SERPULA NARCONENSIS BAIRD, 1885 (POLYCHAETA: SERPULIDAE) IN SOUTH GEORGIA (ANTARCTICA)
Ramos, A.1 & San Martin, G.2
1 Instituto Espanhol de Oceanografia. Puerto Pesquero s/n. E-29640 Fuengirola,
Malaga,Spain
2 Laboratorio de Biologia Marina e Invertebrados, Departamento de Biologia
(Zoologia). Univerwsidad Autonoma de Madrid. Canto Blanco E-28049 Madrid.
Spain.
Although the majority of the species of Serpulids encrust their tubes to the substratum for all their length, the distal part may eventually detach and grow erectly, forming dense populations and cementing tubes to each other. These populations are reef-like, and Ten Hove (1979) proposed the term "aggregate" for these serpulid mass occurrences. Many serpulid "reefs", or massive occurrences, both recent and fossil, have beeen recorded, mainly from temperate and tropical waters. Serpula narconensis Baird, 1885 is a very common species distributed exclusively in Antarctic seas. A single "reef" of this species has been reported until now, in Ellis Fjord (Davis Sea), by Kirkwood & Burton (1988). We report a new "reef" of this species in South Georgia islands shelf. This information about the mass occurrence of this species is very interesting, as it is the second one reported in Antarctica, and its location is in habitat conditions that are very different from that of all other species of serpulids described until now. This new "reef" reaches about 40m and is located in the open sea, at a depth of between 91 and 105m, on a rocky substratum, with a very high water transparency.