Orbiniella Day, 1954

Blake, James A., 2021, New species and records of Orbiniidae (Annelida, Polychaeta) from continental shelf and slope depths of the Western North Atlantic Ocean, Zootaxa 4930 (1), pp. 1-123 : 99

Genus Orbiniella Day, 1954

Type-species: Orbiniella minuta Day, 1954 , by monotypy.

Synonym: Falklandiella Hartman, 1967 . Fide Buzhinskaja 1992: 76. Type species: Falklandiella annulata Hartman, 1967 , by monotypy.

Diagnosis: (after Blake 2017) Body elongate, with separation between thorax and abdomen indistinct, anterior segments may be narrower than more posterior segments, but changing gradually over several segments, or no change in appearance between anterior and posterior segments; prostomium broad or elongate with paired nuchal organs usually present, these sometimes pigmented, eyespots present or absent; peristomium with 1–2 asetigerous rings. Noto- and neuropodia poorly developed, consisting of low tori from which setae emerge; with only simple post-setal lamellae, or these entirely absent; posterior parapodia not elevated and shifted dorsally as in genera of Orbiniinae . Capillary noto- and neurosetae always crenulated or weakly camerated with pointed bristles apparent at relatively low magnification (100x); prominent acicular spines present or absent in either noto- and neuropodia, or entirely absent; furcate setae absent. Branchiae absent.

Remarks. According to Blake (2017, 2020), there are 19 valid species of Orbiniella . Of these, ten species are reported from deep-water habitats exceeding 1000 m. In the present study, three new species of Orbiniella were identified in the ACSAR samples, all of which are from deep water, thus indicating that the majority of species in the genus (13 of 22) occur in deep water.