Polychaeta of the deep Eastern Mediterranean Sea
D. Fiege, R. Barnich and M.N. Ben-Eliahu (Jerusalem); completed
This project aims at a faunal analysis of the benthic fauna in order to understand the structure and functioning of communities in the oligotrophic and exceptionally warm (13°C) deep Eastern Mediterranean. Sampling was carried out during two cruises with RV METEOR in early summer 1993 (METEOR -cruise 25 leg 1) and winter 1998/9 (METEOR-cruise 40 leg 3) in order to cover seasonal variations. These two cruises are related to an earlier one conducted in 1987 (METEOR-cruise 5 leg 1).
During METEOR-cruise 40 a dense assemblage of wormtubes was found in the Ierapetra Trough (42mm m) south of Crete. Up to 160 tubes per square meter could be observed. These tubes extend about 2 cm above the sediment. They are inhabited by the oweniid Myriochele fragilis which obviously 'grazes' on the sediment in a circle around the tubes (s. below). Besides the discovery of this 'polychaete garden' our results confirm earlier observations reporting a low faunal density and diversity for the eastern Mediterranean in general and especially for its deep basins. The highest abundance and diversity of macrobenthic organisms was found in the area north of Crete. With regard to Polychaeta sampled during METEOR-cruises 25 and 40, Spionidae, Syllidae and Paraonidae are the dominant taxa with more than 500 individuals. According to expectations the highest numbers of individuals (>200 in a single sample) were found on stations close to shore (50 – 200 m depth) with one station off the mouth of the Nile being especially rich. Relatively few polychaetes were found on stations exceeding 1000 m depth.
Worth noting is also the rediscovery of the small deep-sea holothurian Penilpidia ludwigi (Marenzeller, 1893) which is considered endemic for the Mediterranean. It was collected alive during METEOR-cruise 25 for the first time after having been described over 100 years ago (s. below).
Based on specimens collected during the above mentioned cruises and supplemented from the collections of the Hebrew University Jerusalem as well as various French expeditions made available through Helmut Zibrowius (Marseille), Nechama Ben-Eliahu (Jerusalem) and Dieter Fiege reviewed the Mediterranean Serpulidae. Besides an overview ot the respective species this paper also presents data on their geographic and depth distribution for the Central and Eastern Mediterranean. In an even more comprehensive approach Dieter Fiege and Ruth Barnich revised the Aphroditoidea of the whole Mediterranean.
Pumice from volcanic eruptions and slag from steamships turned out to be characteristic for benthic samples from the Eastern Mediterranean. They provide a rare supply of hard substrates for deep sediments and are almost always settled by serpulids. During both cruises with RV METEOR plastic bags, tin cans, bottles and other kind of trash was found on most of the stations sampled - even in 4200 m depth (s. below). This trash was especially common in the Cretean Sea which is surrounded by islands and crossed by a number of shipping routes.
Publications:
Ben-Eliahu, M.N. & Fiege, D. (1994): Some species of the aphroditoid family Acoetidae (=Polyodontidae Augener [Polychaeta]) from the Levant and the central Mediterranean. In: Dauvin, J.-C. & Laubier, L. & Reish, D.J. ( eds .), Actes de la 4ème Conference Internationale des Polychètes. Mém. Mus. natn. Hist. nat., 162: 145-161.
Ben-Eliahu, M.N. & Fiege, D. (1995): Polychaeta from the continental shelf and slope of Israel collected by the 'Meteor' 5 expedition (1987). Senck. marit. 25 (4/6): 85-105.
Ben-Eliahu, M.N. & Fiege, D. (1996): Serpulid tube-worms (Annelida: Polychaeta) of the central and eastern Mediterranean with particular attention to the Levant Basin. Senck. marit. 28 (1/3): 1-52.
Fiege, D. & Liao, Y. (1996): Penilpidia ludwigii (Marenzeller, 1893) (Holothurioidea: Elpidiidae) rediscovered from the Eastern Mediterranean Sea. In: Uiblein, F., Ott, J., Stachowitsch, M. (eds.): Biosystematics and Ecology Series No. 11. Deep-sea and extreme shallow-water habitats: affinities and adaptations. p. 61-66.
Barnich, R. & Fiege, D. (2003): The Aphroditoidea (Annelida: Polychaeta) of the Mediterranean Sea. Abhandlungen der Senckenbergischen Naturforschenden Gesellschaft Vol. 559: 1-167.
Fiege, D. Kröncke, I. & Barnich, R. (2000): High abundance of Myriochele fragilis Nilsen & Holthe, 1985 (Polychaeta: Oweniidae) in the Deep Sea of the Eastern Mediterranean. Hydrobiologia, 426: 97-103.
Kröncke, I., Türkay, M. & Fiege, D. (2003): Macrofauna communities in the eastern Mediterranean deep-sea. P.S.Z.N.: Mar. Ecol., 24(3): 193-216.
Myriochele fragilis Penilpidia ludwigi
Macellicephala laubieri Pholoides dorsipapillatus on slag
plastic trash sampled on various stations during METEOR-cruise 25