Three new polar species of Sternaspis Otto, 1821 (Polychaeta: Sternaspidae) Author Salazar-Vallejo, Sergio I. text Zootaxa 2014 3861 4 333 344 journal article 10.11646/zootaxa.3861.4.3 6ff5056b-ce01-4f6c-b32b-b463db92719f 1175-5326 229219 0EBAD66B-F6F1-47A5-9B33-75B39FC9A9EE Key to species of Sternaspis Otto, 1821 (Modified after Salazar-Vallejo & Buzhinskaja 2013 ) 1 Ventro-caudal shield fan with a distinct median notch........................................................ 2 - Ventro-caudal shield fan continuous, without distinct median notch............................................. 12 2(1) Shield with radial ribs and concentric lines distinct........................................................... 3 - Shield with radial ribs distinct, concentric lines barely visible................................................. 10 3(2) Fan with median notch shallow.......................................................................... 4 – Fan with median notch deep; shields usually with concentric bands.............................................. 5 4(3) Shield with distinct concentric bands; main rib and posterior corners directed posteriorly.............................................................................................. S. affinis Stimpson, 1864 (NE Pacific Ocean). - Shield without concentric bands; posterior corners directed laterally......................................................................................... S. scutata ( Ranzani, 1817 ) (Mediterranean Sea and NE Atlantic Ocean). 5(3) Shield with posterior corners distinct in frontal view......................................................... 6 - Shield with posterior corners poorly defined in frontal view.................................................... 7 6(5) Radial ribs and concentric lines distinct, well defined; body whitish to grayish............................................................................................... S. costata von Marenzeller, 1879 (NW Pacific Ocean). - Radial ribs and concentric lines barely defined; body brownish...................... S. sendalli n. sp. ( Antarctic Ocean) 7(5) Anterior keels usually exposed.......................................................................... 8 - Anterior keels rarely exposed; fan barely projecting posteriorly beyond posterolateral corners......................... 9 8(7) Shield with anterior corners projecting at least as far as anterior keels, longer in larger specimens; fan margin crenulated in small specimens, dentate in larger ones....................................... S. buzhinskajae n. sp. (Arctic Ocean) - Shield with anterior corners projecting as far as anterior keels; fan margin smooth to crenulated, never dentate................................................................. S. islandica Malmgren, 1867 (NE Atlantic Ocean, Iceland ) 9(7) Introvert and body with similar pigmentation or introvert paler; shield widest medially.............................................................................................. S. fossor Stimpson, 1853 (NW Atlantic Ocean) - Introvert and body with different pigmentation, introvert darker; shield widest anteriorly........................................................................ S. annenkovae Salazar-Vallejo & Buzhinskaja, 2013 (NW Pacific Ocean) 10(2) Main ribs markedly divergent; fan as wide as anterior margins or wider............................................................................................ S. maior Chamberlin, 1919 (Eastern Pacific, Gulf of California). - Main ribs moderately divergent; fan half as wide as anterior margins........................................... 11 11(10) Posterior margin truncate, with lateral notches; ribs well-developed........................................................................................ S. maureri Salazar-Vallejo & Buzhinskaja, 2013 (Central Eastern Pacific) - Posterior margin with a median notch, lateral notches shallow or indistinct; ribs poorly developed............................................................... S. williamsae Salazar-Vallejo & Buzhinskaja, 2013 (Northeastern Pacific). 12(1) Fan margin crenulated, not projected posteriorly............................................................ 13 - Fan margin denticulate, medially projected................................................................ 18 13(12) Shield with ribs and concentric lines..................................................................... 14 - Shield with ribs; concentric lines indistinct................................................................ 20 14(13) Shield anterior margins rounded........................................................................ 15 - Shield anterior margins acute........................................... S. spinosa Sluiter, 1882 ( Indonesia , Java). 15(14) Shield with posterior corners distinct..................................................................... 16 - Shield with posterior corners indistinct...................................... S. rietschi Caullery, 1944 ( Indonesia ) . 16(15) Posterior corners barely projected beyond fan margin; introvert hooks thick, bronze.......................................................................... S. thalassemoides Otto, 1821 (NE Atlantic Ocean and Mediterranean Sea). - Posterior corners projected beyond fan margin; introvert hooks thin, golden..................................... 17 17(16) Anterior keels shorter than anterior margins; fan markedly crenulated...................................................................................... S. thorsoni Sendall & Salazar-Vallejo, 2013 (Indian Ocean, Arabian Gulf) . - Anterior keels as long as anterior margins; fan barely crenulated... S. piotrowskiae Salazar-Vallejo, 2014 ( Philippine Islands ) 18(12) Fan without lateral notches; body papillae arranged in distinct transverse rows.................................................................................. S. africana Augener, 1918 (Eastern Atlantic Ocean, Ghana to Angola ). - Fan with lateral notches; body papillae distributed homogeneously, not arranged in transverse rows................... 19 19(18) Introvert with about 15 pale hooks per bundle.................................................................................................... S. andamanensis Sendall & Salazar-Vallejo, 2013 (Indian Ocean, Andaman Sea) . - Introvert with about 10 dark hooks per bundle....................................................................................................... S. uschakovi Salazar-Vallejo & Buzhinskaja, 2013 (Northern Pacific Ocean) 20(13) Shield with diagonal rib distinct; shield plates as long as wide. S. princeps Selenka, 1885 (SW Pacific Ocean, New Zealand ) - Shield with diagonal rib indistinct; shield plates wider than long..................... S. monroi n. sp. ( Antarctic Ocean)