Marphysa de Quatrefages, 1865

Molina-Acevedo, Isabel C. & Idris, Izwandy, 2020, Reinstatement of species belonging Marphysa sanguinea complex (Annelida Eunicidae) and description of new species from the mid-Pacific Ocean and the Adriatic Sea, Zootaxa 4816 (1), pp. 1-48 : 3

Genus Marphysa de Quatrefages, 1865

Type species: Marphysa sanguinea ( Montagu, 1813)

Diagnosis (modified after Molina-Acevedo & Carrera-Parra 2017). Single-lobe prostomium or bilobed; five prostomial appendages without articulations ( Fig. 1A ); eyes present or absent. Peristomium without peristomial cirri. Maxillary apparatus with four pairs of maxillae and an unpaired on left side ( Fig. 1D ); MI forceps-like, without attachment lamella, with falcal arch well developed, in angular shape, with the outer base of MI concave and inner base oblique ( Fig. 1D ); MII without attachment lamella; MIII curved, forming part of distal arc, with attachment lamella sclerotized, situated at the center of right edge of maxilla; MIV with attachment lamella sclerotized, situated in anterior edge of maxilla. Maxillae V unidentate. Branchiae distributed throughout the body. Dorsal cirri without articulation; postchaetal lobe well developed in anterior region ( Fig. 1 G–K); ventral cirri with swollen base, oval or circular, in more than half of parapodia of the body ( Fig. 1 G–K). Aciculae dark. Supracicular chaetae include limbate; pectinate chaetae thin narrow isodont in anterior region of the body ( Fig. 1M ), pectinate chaetae isodont wide in median-posterior region, and/or thick wide anodont pectinate chaetae in posterior region ( Fig. 1N, P ). Subacicular chaetae include compound falcigers, spinigers ( Fig. 1L ) or both. Subacicular hook, dark, or translucent, bidentate, or unidentate. Pygidium with two pairs of anal cirri, without articulation.

Remarks. The genus Marphysa is represented by more than 90 species that are divided into several groups: A, B1, B2, C1, C2, D1, and D2 ( Fauchald 1970); Bellii group, Sanguinea group, and “Mortenseni group ( Orensanz 1990); and Teretiuscula group ( Glasby & Hutchings 2010). This diversity of forms and groups leads to the conclusion that the generic boundaries of Marphysa are in need of invetigation. Although Zanol et al. (2014) found that Marphysa formed a monophyletic grouping in a phylogenetic analysis of the Eunicidae , two new genera were erect- ed ( Treadwellphysa Molina-Acevedo & Carrera-Parra, 2017 , and Paucibranchia Molina-Acevedo, 2018 ) based on species previously assigned to two of the Marphysa groups ( Fauchald 1970). Morphological variability and the description of new genera suggest that monophyly of Marphysa , as presently define, is doubtful. Therefore, it is still necessary to perform revisionary work on the genus, ideally based on evidence morphological, molecular, ecological data, to resolve two main issues: (1) to corroborate if questionable taxa belong to Marphysa or different genera and (2) to achieve a more precise delimitation of the genus Marphysa .

Figures

FIGURE 1. Marphysa americana. Holotype BNHM 1932.12.24.554-556. A. Anterior end, dorsal view; B. Anterior end, ventral view; C. Anterior view, lateral view; D. Maxillary apparatus, dorsal view; E. Left MI-II-III-IV-V, lateral view; F. Mandible; G. Parapodium 3; H. Parapodium 6; I. Parapodium 12; J. Parapodium 247; K. Parapodium 377; L. Compound spinigers, chaetiger 6; M. Thin, isodont narrow, asymmetric, with long and slender teeth, chaetiger 6; N. Thick, isodont wide, symmetric, with short and slender teeth, chaetiger 325; O. Thick, isodont wide, asymmetric, with long and thick teeth, chaetiger 325; P. Thick, anodont wide, asymmetric, with long and thick teeth, chaetiger 377; Q. Subacicular hook, chaetiger 367.All chaetigers in anterior view; al-MIII: attachment lamella MIII; al-MIV: attachment lamella MIV. Scale bars: A–C, 3 mm; D, 1.4 mm; E. 0.9 mm; F. 1.3 mm; G–K, 0.2 mm; L, 0.1 mm; M–Q, 30 µm.