A new species of Isodictya (Porifera: Poecilosclerida) from the Southern Ocean

• Published in: Polar Biology
• Main Authors: Ríos, P. (Pilar), Riesgo, A. (Ana), Taboada, S. (Sergi), Cristobo, J. (Javier)
• Format: Article in Journal/Newspaper
• Language: English
• Published: Springer Science and Business Media LLC 2020
• Subjects: Antarctic; Antarctic Peninsula; Bellingshausen Sea; Deception Island; Marguerite; Marguerite Bay; Peter I Island; Southern Ocean; The Antarctic; Antarc*; Antarctica; Low Island
• Online Access: http://hdl.handle.net/10508/15430; https://doi.org/10.1007/s00300-020-02654-x

We discovered a new species of Porifera belonging to the genus Isodictya Bowerbank, 1864 during cruises aboard R/V Hesperides in Antarctica. Collected samples are mostly part of the surveys of the Spanish project BENTART whose main objective has been to study the benthic communities inhabiting sea bottoms of Livingston and Deception Island in the South Shetlands archipelago and the Antarctic Peninsula. Isodictya filiformis sp. nov., described here, is characterized by its fragile and thin morphology (very different from other known species in the area) and by having microxeas as additional microscleres. Three specimens were collected from Marguerite Bay, Low Island and Deception Island (Antarctic Peninsula) and one specimen at Peter I Island (Bellingshausen Sea). Its presence in Peter Island is quite relevant as this location is 390 km away from the nearest coast in the Bellingshausen Sea, an area that has scarcely been investigated in the past. However, results from the Bentart 03 Expedition seem to indicate that Peter I Island has a wide variety of benthic organisms, in contrast to the deep adjacent areas of Bellingshausen Sea. Apart from the morphological analyses, we place the new Isodictya species within its phylogenetic context using two nuclear markers (18S rDNA and 28S rDNA) and provide some information about the ecological preferences of the new species.