Benoit Gouillieux

Heteromysis (Heteromysis) microps (Crustacea, Mysidae), a commensal species for Upogebia pusilla (Crustacea, Upogebiidae) in Arcachon Bay (NE Atlantic Ocean)

BackgroundThe mysid Heteromysis (Heteromysis) microps is reported for the first time in the Bay of Biscay. During surveys carried out between March and September 2015 in Arcachon Bay, mysid specimens were fortuitously collected from Upogebia pusilla burrows.ResultsDetails on morphology, colour pattern and behaviour of H. microps are provided.ConclusionsCommensalism was frequently mentioned for Heteromysis species but never reported for H. microps. In this study, commensalism seems to be proved between the mysid and its host U. pusilla.

Elasmopus thalyae sp. nov. (Crustacea: Amphipoda: Maeridae), a new benthic species from soft and hard bottoms of Arcachon Bay (SE Bay of Biscay)

A new species of Elasmopus is described and figured from specimens collected in different benthic communities of Arcachon Bay. It can be distinguished from its closest relative E. rapax by the palmar ornamentation of male gnathopod 2 propodus (shelf and 2 teeth). It preferentially lives on hard bottoms (in mussel fouling of navigation buoys, Sabellaria spinulosa reefs, algal rocky bottoms, Laminaria and Saccorhiza bulbs and as epibiont on the carapace of Maja brachydactyla) but also less abundantly on naked sandy bottoms. An identification key of Atlantic and Mediterranean European species is also given.

New records of Spio symphyta and Spio martinensis (‘Polychaeta’: Canalipalpata: Spionidae) from Arcachon Bay (France), NE Atlantic

This paper presents new records of Spio symphyta Meißner et al., 2011 and Spio martinensis Mesnil, 1896 (‘Polychaeta’: Canalipalpata: Spionidae) from Arcachon Bay (southern Bay of Biscay). For both species the new records represent an extension of their known distributional range. The two species have probably been present in Arcachon Bay for several years but were confused with other species of the genus Spio. Spio symphyta was identified at five locations in Arcachon Bay in 2009 and 2013 and S. martinensis at three stations in 2012 and 2013. A detailed and illustrated description of specimens from Arcachon Bay is provided. Important characters of Spio spp. occurring in the area are compared.