Aricidea Webster, 1879

Barroso, R., Paiva, P. C. & Ranauro, N., 2020, Three new species of Aricidea (Acmira) (Annelida: Paraonidae) from the Continental Shelf of Eastern Brazil, Southwestern Atlantic, Zootaxa 4838 (3), pp. 415-426 : 417

Genus Aricidea Webster, 1879

Type species: Aricidea fragilis Webster, 1879

Diagnosis (after Blake 2016): Body long, slender and cylindrical in cross section. Prostomium conical with a median antenna (may be absent), a pair of nuchal slits and a terminal sensory organ. Peristomium more or less fused to the prostomium, ventrally forming lateral lips of mouth; ventral part of first two segments forming posterior lip. Three pre-branchial segments or branchiae absent. Parapodia biramous, lacking distinct chaetal lobes, but with digitiform to filiform postchaetal notopodial lobes (= dorsal cirri); with or without postchaetal neuropodial lobes on some anterior segments (= ventral cirri). Chaetae include simple capillaries in both noto- and neuropodia and modified neurochaetae of various types in postbranchial segments. Pygidium with 2–3 filiform anal cirri.

Remarks. Although in a recent study the genus Aricidea was considered as a junior synonym of Paraonis ( Langeneck et al. 2019) , we preferred to maintain the traditional scheme proposed by Strelzov (1973) for the genus, until a more comprehensive phylogeny with more extensive taxon sampling becomes available, with other species of Paraonis and even more specimens of Paraonis fulgens ( Levinsen, 1884) . A risk for accepting Langeneck et al. (2019) proposed scheme is that the samples of Aricidea fragilis Day, 1963 , the type-species of Aricidea , were from Mediterranean specimens while the type locality is eastern USA. Moreover, the genus Blakeia , proposed as new, is pre-occupied in the Lepidoptera by Kiriakoff, 1967 and as a junior homonym is not available. Furthermore, the typespecies suggested is A. simplex from South Africa, however the samples used were from Californian specimens.

Therefore, we opted to be conservative until more evidence is available. As regards to the stability of the classification, it is important to mention that once the genus Aricidea is the most species-rich within the family, the proposed change would affect the taxonomic status of more than 100 species.