Outbreak of a neurotoxic side-gilled sea slug (Pleurobranchaea sp.) in Argentinian coasts

NAHUEL EMILIANO FARIAS; SANDRA OBENAT; ALEJANDRA B. GOYA

NEW ZEALAND JOURNAL OF ZOOLOGY

RSNZ PUBLISHING

Lugar: Auckland; Año: 2015 vol. 42 p. 1 - 6

0301-4223

From 2009 to date we have been registering the outbreak of an unknown side gilled sea-slug of the genus Pleurobranchaea in coastal waters of Argentina, southwestern Atlantic Ocean. Examination of both external macroscopic features and internal structures via electron microscopy did not allow us to conclusively identify the species. Nevertheless, since Argentinian specimens closely resemble Pleurobranchaea maculata (a species native from Australia and New Zealand known to contain a potent neurotoxin) we performed a bioassay in our specimens that was positive for neurotoxins. The presence of this pleurobranch in Argentinian waters is of concern beyond the ecological effects of the outbreak of a marine predator and requires urgent attention. This work provides a guide to distinguish between this unidentified species and the sympatric cryptogenic P. inconspicua, based on features that are readily observable in fresh and preserved specimens. We discuss the potential effects of this outbreak on local communities.