Pseudotachidiidae (Copepoda: Harpacticoida) from the Angola Basin and the Antarctic deep sea, with the description of a new species of Paradanielssenia Soyer, 1970

The species diversity of Copepoda Harpacticoida in the deep sea of the Angola Basin (DIVA I expedition) and in the Weddell Sea (ANDEEP II expedition) is investigated. In both areas, the Pseudotachidiidae Lang, 1936, together with Ameiridae Monard, 1927, Argestidae Por, 1986 and Ectinosomatidae Sars, 1903, are richest in species and numbers of individuals. From two DIVA stations and from ANDEEP station 138, all adult specimens have been determined at the level of 'working species'. Pseudomesochrinae Willen, 1996, represented mainly by the single taxon Pseudomesochra T. Scott, 1902 and Paranannopinae Por, 1986 turned out to be the 'dominant' taxa in terms of abundance and species number. A new species of Paradanielssenia Soyer, 1970 is described, which was encountered in relatively high abundances in almost every replicate sample from the DIVA stations. A key to the known species of the taxon Paradanielssenia is given.