Description of a new species of Microcanuella Mielke, 1994 (Copepoda: Polyarthra: Canuellidae) from the Great Meteor Seamount plateau (subtropical NE Atlantic Ocean), with remarks on the geographical distribution of the genus

The species Microcanuella secunda sp. n. (Copepoda, Polyarthra, Canuellidae) is described from the plateau of the Great Meteor Seamount. It can be clearly identified as Microcanuella Mielke, due to the following generic autapomorphies: (1) Body size <700 μm; (2) Reduced armature of P4 exp3 and enp3 with only 2 setae; (3) P1 enp3 with at most 4 elements and (4) P1 exp3 with at most 5 elements. As this is the second described species of Microcanuella, an extended generic diagnosis is provided. Furthermore, M. secunda sp. n. can be separated from Microcanuella bisetosa Mielke on the basis of the following apomorphic characters: (A) A1: 3rd segment with 3 long, rat-tailed setae; (B) A2 enp1 with 1 seta; (C) Mxl basis without endites and with 6 setae.M. bisetosa was found in the Pacific (Punta Morales, Costa Rica), M. secunda sp. n. and two closely related but undescribed species in the Atlantic Ocean (Great Meteor Seamount, Seine Seamount, Sedlo Seamount). All species are known from only one locality each, hence each one of them might be endemic. However, as the genus is widely distributed and present on different seamounts, it can be supposed that seamounts act as stepping stones within this genus.