Heteromastus gusipoensis sp. nov. A anterior end, dorsal view (holotype, NA00155561) B same, lateral view C posterior abdominal segments, left lateral view (holotype, NA00155561) D posterior end, dorsal view (holotype, NA00155561) E abdominal short-shafted hook, frontal view F thoracic long-shafted hook, lateral view G abdominal short-shafted hook, lateral view. Abbreviations: ac, anal cirrus; cc, capillary chaetae; Ch, chaetiger; gp, genital pore; hh, hooded hooks; lo, lateral organ; mf, main fang; neu, neuropod; no, notopod; per, peristomium; pro, prostomium; prob, proboscis; pyg, pygidium.