Holothurian (Echinodermata) diversity and distribution in the central Cantabrian Sea and the Avilés Canyon System (Bay of Biscay).

Here we report on the holothurian fauna at the Avilés Canyon System (Natura 2000 Site of Community Importance), central Cantabrian Sea, northern Spain. The samples were collected during several cruises covering the shelf, the continental slope and the abyssal depth. We identified 174 specimens, belonging to 35 species of the seven orders of class Holothuroidea. Depth was the main structuring agent. Multivariate analysis allowed the differentiation of four main assemblages which corresponded to abyssal plain, lower continental slope, upper continental slope, and continental shelf. Depth had a significant effect on holothurian species richness (it increased with depth at an approximate rate of 1.7 species 1000 m-1), which is consistent with previously described global patterns.

Rediscovery and redescription of Leodice laurillardi (Quatrefages, 1866) comb. nov. (Annelida: Eunicidae)-a rare European polychaete or just an overlooked species?

The eunicid polychaete, Eunice laurillardi Quatrefages, 1866, originally described from the central Mediterranean, has been discovered on the northern Iberian Peninsula, constituting the first report of the species since its original description. The new specimens are compared with the type collection and the species is redescribed. Furthermore, the species is assigned to the genus Leodice Savigny in Lamarck, 1818, based on information provided by re-examination of type material and the newly collected specimens. A summary of the complex taxonomic history of the species and a discussion of its current status are also provided.

On the occurrence of the fireworm Eurythoe complanata complex (Annelida, Amphinomidae) in the Mediterranean Sea with an updated revision of the alien Mediterranean amphinomids.

The presence of two species within the Eurythoe complanata complex in the Mediterranean Sea is reported, as well as their geographical distributions. One species, Eurythoe laevisetis, occurs in the eastern and central Mediterranean, likely constituting the first historical introduction to the Mediterranean Sea and the other, Eurythoe complanata, in both eastern and Levantine basins. Brief notes on their taxonomy are also provided and their potential pathways for introduction to the Mediterranean are discussed. A simplified key to the Mediterranean amphinomid genera and species of Eurythoe and Linopherus is presented plus an updated revision of the alien amphinomid species reported previously from the Mediterranean Sea. A total of five exotic species have been included; information on their location, habitat, date of introduction and other relevant features is also provided.

Mooreonuphis vespa, a new brooding species of Onuphidae (Annelida) from northern Spain (Bay of Biscay).

A new species of the genus Mooreonuphis Fauchald, 1982 collected from the Cantabrian shelf (Bay of Biscay) is described. Mooreonuphis vespa sp. nov. constitutes the first record of this genus in European waters and is characterised by: conspicuous dark brown transverse segmental pigment bands; antennae and palps with 3-5 basal ceratophoral rings and a very long distal ring; unusually long and slender peristomial and dorsal cirri; simple branchiae from chaetiger 17-19. We present observations on its reproductive biology (including brooding behaviour) and remark on the biogeography of the genus.