Fabricinuda Fitzhugh, 1990

López, Eduardo & Rodríguez, Carmen T., 2008, A new species of Fabricinuda Fitzhugh, 1990 (Fabriciinae: Sabellidae: Polychaeta) from the Caribbean, with an emendation of the genus, Journal of Natural History 42 (29 - 30), pp. 1937-1949 : 1939-1943

Fabricinuda Fitzhugh, 1990 emended

Diagnosis

Small bodied fabriciins, with eight thoracic and three abdominal chaetigers. Branchial crown composed of three pairs of radioles, dorsal lips well developed or absent, ventral filamentous appendages unbranched and vascularized or absent; branchial crown shifted dorsally to some extent; mouth in typical sabellid position between branchial lobes or shifted dorsally to attachment position of branchial lobes. Peristomium divided in two rings; anterior one as long as wide or longer, longer than posterior one; annulation between the two rings indistinct dorsally; rounded lobe present or absent on either side of dorsal midline; anterior peristomial ring collar as a low ridge all around; peristomial eyes black, rounded to crescentic. Inferior thoracic notochaetae short elongate, narrowly hooded on chaetiger 2; pseudospatulate from chaetiger 3 to chaetiger 7 or 8; if not pseudospatulate short elongate, narrowly hooded on chaetiger 8. Thoracic uncini acicular; large secondary tooth slightly offset from midline; small hood present. Abdominal neurochaetae as modified, elongate, narrowly hooded. Manubrium of abdominal uncini as long as dentate region; dentate region with several teeth per row. Pygidial eyes black.

Remarks

When it was first described, Fitzhugh (1990a) based the monophyly of the genus in three apomorphies, namely the reduction of the anterior peristomial ring collar to a low ridge, the anterior peristomial ring being at least as wide as long, and the occurrence of pseudospatulate inferior notochaetae on chaetigers 3–8. In subsequent papers ( Fitzhugh 1998, 2002), the second of these characters suffered a number of redefinitions in such a way that it was discarded as a valid autapomorphy of the genus, although it did not change the validity of the genus, which in every analysis performed was found to be monophyletic. In these analyses, the phylogenetic relationships among the species were also assessed and Fabricinuda pseudopalpa Fitzhugh, 1990 , with dorsal lips but without ventral filamentous appendages and with anterior peristomial ring as long as wide, appeared to be the most plesiomorphic species. From the present analysis, it seems clear that the new species herein described must be referred to genus Fabricinuda . Although it does not exactly fit the original generic diagnosis, the erection of a new genus is not justified; on the contrary, the generic diagnosis should be modified to accommodate the new species. Thus the sole valid autapomorphy for the genus is the reduction of the anterior peristomial ring collar to a low ridge.