On the phylogeny of Ischyroceridae (Amphipoda, Senticaudata, Corophiida), with the description of a new genus and eight new species from deep-sea Brazilian waters

Abstract

The family Ischyroceridae is analysed herein by cladistic methods based on morphological characters, using both PAUP 4.0b and TNT. The data matrix of 41 characters × 32 terminal taxa was constructed using DELTA. Based on the results, we comment on the phylogenetic relationships of certain genera and their synapomorphic characters, also discussing the phylogenetic position of Myersius gen. nov., which appeared as the sister group of Bathyphotis. In addition, Pseudischyrocerus crenatipes is removed to Bathyphotis, for which a new diagnosis is provided. A taxonomic study with the Ischyroceridae collected on the continental slope (depth, 700–2000 m) in the Campos Basin (20.5–24°S, 40–41°W) was also performed. Samples were collected in November–December 2002 and July–August 2003 using a box core device. As a result, a new genus and eight new species are described: Bonnierella campensis sp. nov., Bonnierella laurensi sp. nov., Myersius denticaudatus gen. et sp. nov., Notopoma lowryi sp. nov., Notopoma teresae sp. nov., Pseudericthonius bousfieldi sp. nov., Pseudericthonius concavus sp. nov., and Pseudischyrocerus caecus sp. nov. The genus Bonnierella is recorded for the first time from Brazilian waters, and the subspecies Bonnierella linearis linearis and Bonnierella linearis californica are elevated to species rank. Keys to the genera of Ischyroceridae used in the cladistic analysis and the world species of Notopoma are given. © 2014 The Linnean Society of London