Leitoscoloplos Day, 1977

Blake, James A., 2020, New species and records of deep-water Orbiniidae (Annelida, Polychaeta) from the Eastern Pacific continental slope, abyssal Pacific Ocean, and the South China Sea, Zootaxa 4730 (1), pp. 1-61 : 6

Genus Leitoscoloplos Day, 1977

Type-species: Haploscoloplos bifurcatus Hartman, 1957 , designated by Day 1977.

Diagnosis. (after Blake 2017) Prostomium pointed, conical; peristomium typically with one achaetous ring, but with additional superficial annulae on some species. Branchiae lacking, or present from posterior thoracic, transitional, or abdominal setiger. Posterior thoracic setigers with 0–2 postsetal lobes and 0–2 subpodial lobes; abdominal setigers with 0–4 subpodial papillae; stomach papillae rare, interramal cirri present or absent. Thoracic neurosetae only crenulated capillaries. Without abdominal neuropodial spines, with 2–3 imbedded aciculae present or absent. Notopodial furcate setae present or absent in abdominal segments.

Remarks. Blake (2017) referred 27 species to Leitoscoloplos . Five new species of Leitoscoloplos : L., cliffordi n. sp., L. gordaensis n. sp., L. lunulus n. sp., L. sahlingi n. sp., and L. williamsae n. sp. have been discovered from deep-water habitats in the northeastern Pacific and are here described. These five new species bring the total number of known species of Leitoscoloplos to 32. Four of the new species belong to the L. kerguelensis ( McIntosh, 1885) group as defined by Blake (2017), in which the branchiae begin on an anterior abdominal segment. The fifth species, L. sahlingi n. sp., is in a group that includes L. pugettensis ( Pettibone, 1957) , in which branchiae are first present from a posterior thoracic segment.

Seven species of Leitoscoloplos occur along the continental margin of the northeastern Pacific Ocean in depths of about 750 m or greater. In order to help readers separate these deep-water species, a key is presented here. Additional data on deep-water Leitoscoloplos from a global perspective is presented in the Discussion at the end of this paper.