NEW ASSOCIATIONS BETWEEN SYLLID POLYCHAETES (SYLLIDAE) AND HERMIT CRABS, GIANT CRABS AND SPONGES
López, E.1; Britayev, T. A.2; San Martín, G.1; Martin, D.3 & Abelló, P.4
1Departamento de Biologia, Unidad de Zoologia, Facultad de Ciencias, Universidad Autonoma de Madrid, 28049, Madrid, Espana.
2A.N.Severtzov Institute of Ecology and Evolution, Russian Academy of Sciences, Leninsky Prosp. 33, Moscow 117071, Russia.
3Centre d'Estudis Avançats de Blanes (CSIC), Camí de Sta. Bàrbara S/N, 17300 Blanes (Girona). Spain
4Institut de Ciencies del Mar de Barcelona (CSIC), Passeig Joan de Borbó S/N, 08039 Barcelona. Spain.
The syllids are a very large and diverse group of polychaetes. They are found inhabiting many different habitats, which include the surfaces and inner channels and cavities of other marine invertebrates. About 28 species are known to be associated with cnidarians, echinoderms and ascidians but they are particularly frequent and abundant in sponges (Martin and Britayev, 1998), where they often exceed the density of other inhabitants (Dauer, 1974). Conversely, only one association between syllids and crustaceans is known to date: that of Syllis cornuta Rathke inhabiting the shell of an unidentified hermit crab mentioned by Fauvel (1923). In this study, we report 8 new associations between syllids and other benthic invertebrates (i.e. hermit crabs, giant crabs and sponges). These are: (1) Pionosyllis magnifica Moore, Syllis armillaris (Müller), Syllis ferrani Alós and San Martín, Syllis gerlachi (Hartmann-Schöder) and Syllis gracilis Grube from gastropod shells occupied by different species of hermit crabs; (2) Pionosyllis magnifica from the branchial chambers of the giant crab Paralithodes camtschatica; and (3) Haplosyllis spongicola (Grube) from the sponges Haliclona sp. and Aaptos cf. aaptos. In addition, this study allowed us emend the descriptions of Pionosyllis magnifica and Syllis armillaris, as well as to provide new ecological data on the infestation by Haplosyllis spongicola.