Three new species of Heteromastus (Annelida, Capitellidae) from Korean waters, with genetic evidence based on two gene markers

Abstract. Three undescribed species of Heteromastus Eisig, 1887 were collected from intertidal to sublittoral habitats in western and southern waters of Korea. Heteromastus namhaensis sp. nov. is distinguishable from other congeners by the presence of hemispheric notopodial lobes in the posterior abdomen. Heteromastus gusipoensis sp. nov. closely resembles H. tohbaiensis Yabe & Mawatari, 1998 in the absence of posteriorly extended abdominal notopodial lobes, but differs in the absence of eyespots on the prostomium and distinct node on the shaft of thoracic hooks in H. gusipoensis. Heteromastus koreanus sp. nov. is similar to H. filiformis sensu Hutchings & Rainer, 1982 in the shape of abdominal notopodia, but clearly differs in dentition of the abdominal hooks and methylene green staining pattern (MGSP). DNA sequences (mtCOI and histone H3) of these new Korean species were compared with all sequences of Heteromastus species available in the public database. Molecular results showed distinct genetic differences among these three new Korean species at species level. Comparison of mtCOI gene revealed significant genetic difference between H. filiformis and these Korean species. A comprehensive comparison between three Heteromastus species of present study and their closely related congeners is conducted based on morphological and genetic results.