A new Southern Ocean species in the remarkable and rare amphipod family Podosiridae (Crustacea: Amphipoda) questions existing systematic hypotheses

• Published in: Zoological Journal of the Linnean Society
• Main Authors: Ashford, Oliver S, Horton, Tammy, Roterman, Christopher N, Thurston, Michael H, Griffiths, Huw J, Brandt, Angelika
• Other Authors: National Oceanography Centre, Climate Linked Atlantic Section Science
• Format: Article in Journal/Newspaper
• Language: English
• Published: Oxford University Press (OUP) 2019
• Subjects: Animal Science and Zoology; Ecology, Evolution, Behavior and Systematics; Southern Ocean; South Shetland Islands; South Orkney Islands
• Online Access: http://dx.doi.org/10.1093/zoolinnean/zlz145; http://academic.oup.com/zoolinnean/article-pdf/190/2/613/33826384/zlz145.pdf

Abstract The amphipod family Podosiridae is unusual in that it combines morphological elements of the disparate families Podoceridae and Eusiridae. Here, we describe a new species in the family from specimens collected from the Southern Ocean in the vicinity of the South Orkney Islands and South Shetland Islands. We present mitochondrial (COI and 16S) and nuclear (18S) nucleic acid sequences for this and a congeneric species and use these to investigate the phylogenetic placement of Podosiridae within the Amphipoda. Our results do not provide evidence for a close relationship between Podosiridae and Podoceridae or Eusiridae, suggesting that the superficial similarity between these families is the result of morphological convergence. Instead, it is likely that Podosiridae are more closely related to families within Amphilochidira, such as Stenothoidae. Definitive placement of Podosiridae in the Amphipoda awaits further specimen collection, additional nucleotide data (including sequences from the Hyperiopsidae and the Vitjazianidae) and a more directed analysis of relationships within this portion of the amphipod phylogeny.