A new record and a redescription of <i>Brania subterranea</i> (Polychaeta, Syllidae): Léopold III Biological Station, Laing Island. Contribution n° 18 = Une nouvelle station et une rédescription de <i>Brania subterranea </i>(Polychaeta, Syllidae): Station Biologique Léopold III, Ile de Laing. Contribution n° 18

Brania subterranea (Hartmann-Schroeder, 1956), recorded for the first time from the West Pacific coasts, is studied by scanning electron microscopy. A well developed nuchal organ with cilia bearing disk-like enlargements could be demonstrated. The entrance of the pharynx carries ten papillae and a circlet of ordinary cilia. The fine structure of the simple and compound bristles and also their distribution in correlation with the length of the specimens is given in detail

Distribution of benthic macrofauna in the western Scheldt estuary (The Netherlands)

Twenty stations distributed over four transects in the Western Scheldt estuary were sampled, and the benthic invertebrate community structure examined. Based on cluster analysis and Detrended Correspondence Analysis two main species-site groups emerged: (1) a muddy and fine sand assemblage in the shallow parts that featured a dominance of species belonging to the Macoma balthica community, (2) a medium sand assemblage in the deeper parts.The distribution and abundance of the species seemed primarily determined by the sediment factors but are also influenced by the salinity-gradient

On the pisionids (Polychaeta: Pisionidae) from Papua New Guinea, with a description of six new species

Out of eight species of pisionids sampled in Papua New Guinea, six are new to science: Pisione helenae n.sp., P. parhelenae n. sp., P. parva n. sp.,P. brevicirra n. sp.,P. ungulata n. sp. and P. primitiva n. sp. Some remarks are given for P. subulata Yamanishi, 1992, new for Papua New Guinea, and for P. papuensis Govaere & De Wilde, 1993. Special attention was paid to some female worms. A key is included for the Pisionidae of Papua New Guinea

<i>Pisione papuensis</i> n. sp. (Polychaeta: Pisionidae) a new pisionid from Papua New Guinea

A new species of the genus Pisione, described here as Pisione papuensis n. sp. was collected by the first author from Laing Island, Papua New Guinea, in september-november 1985. The species belongs to the gopalai-complexa-alikunhii-africana group of Laubier

Macrobenthos in the Western Schelde estuary

Species richness, density and diversity of macrobenthos of the Western Scheldt river were measured in September 1980 over four transects. Muddy sands over the whole salinity range contain representative of the Macoma balthica community, whereas some species of the Abra alba community are present in the more saline parts of the river. Diversity and species richness decrease with decreasing salinity

A simple device for taking undisturbed sediment cores in shallow water

A light weight and handy sampler is designed for taking undisturbed sediment cores

Benthic communities in the Southern Bight of the North Sea and their use in ecological monitoring

Macrobenthic and meiobenthic communities of an area off the Belgian coast of the North Sea were studied from 1970 until 1975 at 74 stations. On the basis of both macro- and meiobenthos, three zones can be distinguished in the area. The coastal zone is characterized by the macrobenthic Abra alba community, corresponding to the meiobenthic Microarthridion littorale-Halectinosoma herdmani community, and the open sea zone by the macrobenthic Venus gallina community and the meiobenthic Leptastacus laticaudatus-Paramesochra helgolandica community. In between is a transient zone where elements of both other zones mix. The distribution of these zones is governed by the hydrodynamical regime of the region, especially by the residual and tidal current system of the Southern Bight. Within the coastal zone, the composition of the community is influenced by pollution which especially affects the epibenthic detritus-feeders of the meiobenthos. The spatial stability of parameters describing community structure can be used for monitoring changes. Temporal characteristics of these parameters could not be investigated properly, but diversity seems to be much stabler than biomass

Benthic studies of the Southern Bight of the North Sea and its adjacent continental estuaries: Progress Report 1

A summary of work on benthic communities in the Southern Bight of the North Sea and adjacent estuaries is presented. This work investigates patterns in species composition, in density and biomass which are stable enough, both in the temporal and spatial domain, to be used as baseline data in monitoring, and from which information on systems functioning can be obtained