Three new species of the genus Ischnomesus (Isopoda: Asellota: Ischnomesidae) from Brazilian deep sea Author Souza-Filho, Jesser F. text Zootaxa 2017 2017-08-29 4312 2 259 276 journal article 32273 10.11646/zootaxa.4312.2.3 749ffcd5-2b11-4a35-a97e-a6f416e251f4 1175-5326 852812 F07Dc169-C969-48B0-B74F-Eb853539Ce86 Ischnomesus Richardson, 1908 Ischnosoma G.O. Sars, 1868 : 84 . Ischnomesus Richardson, 1908 : 81 ;— Hansen, 1916 : 56 ;— Gurjanova, 1932 : 40 l;— Wolff, 1956 : 88 ;— Menzies, 1962 : 111 ;— Wolff, 1962 : 73 ;— Menzies & George, 1972 : 971 ;— Kussakin, 1988 : 419 ;— Merrin & Poore, 2003 : 290 ;— Kavanagh et al. , 2015 : 203 . Rhabdomesus Richardson, 1908 : 81 . Bactromesus Wolff, 1962 : 83 . Type species: Ischnosoma bispinosum G.O. Sars, 1868 (by monotypy). Diagnosis. See Kavanagh et al. (2015) . Species included : Ischnomesus anacanthus Wolff, 1962 ; I. andriashevi Birstein, 1960 ; I. antarcticus Schultz, 1979 ; I. armatus Hansen, 1916 ; I. bacilloides ( Beddard, 1886 ) ; I. bacillopsis ( Barnard, 1920 ) ; I. bacillus ( Beddard, 1886 ) ; I. bidens Menzies, 1962 ; I. birsteini Wolff, 1962 ; I. bispinosus ( G.O. Sars, 1868 ) ; I. bruuni Wolff, 1956 ; I. calcificus Menzies & George, 1972 ; I. caribbicus Menzies, 1962 ; I. carolinae Chardy, 1974 ; I. chardyi Kussakin, 1988 ; I. decemspinosus Menzies, 1962 ; I. elegans Menzies, 1962 ; I. elongatus Birstein, 1963 ; I. fragilis Birstein, 1971 ; I. glabra Kensley, 1984 ; I. gracilis ( Birstein, 1960 ) ; I. harrietae Kavanagh, Frutos & Sorbe, 2015 ; I. justi Merrin & Poore, 2003 ; I. kussakini nom. nov. (Kussakin, 1982); I. latimanus Birstein, 1971 ; I. magnificus Menzies, 1962 ; I. multispinis Menzies, 1962 ; I. norvegicus Svavarsson, 1984 ; I. paucispinis Menzies, 1962 ; I. planus Wolff, 1962 ; I. profundus Hansen, 1916 ; I. roseus Wolff, 1962 ; I. simplex Menzies & George, 1972 ; I. simplissimus Menzies, 1962 ; I. spaercki Wolff, 1956 ; I. tasmanensis Merrin & Poore, 2003 ; I. vinogradovi Birstein, 1963 and I. wolffi Menzies, 1962 . Remarks . According to Kavanagh et al . (2015) , the freely articulating posterior pereonites, pleonite 1 and pleotelson observed in Ischnomesus is a condition presumed to be plesiomorphic, with other genera showing various degrees of fusion of the pereonites (e.g. pereonites 5–7, pleonite and pleotelson fused together in genus Haplomesus ; Kavanagh & Wilson 2007 ). Uniarticulate uropods have been described by Merrin & Poore (2003) for Ischnomesus justi , so the biarticulate uropods may not be a diagnostic character for the genus, although all other species, described with this structure, have biarticulate uropods.