Eunice Cuvier, 1817

Zanol, Joana, Hutchings, Pat A. & Fauchald, Kristian, 2020, Eunice sensu latu (Annelida: Eunicidae) from Australia: description of seven new species and comments on previously reported species of the genera Eunice, Leodice and Nicidion, Zootaxa 4748 (1), pp. 1-43 : 3

Eunice Cuvier, 1817

Description. Prostomium with three antennae and a pair of palps; prostomial appendages smooth or irregularly articulated; pair of peristomial cirri present. Mandibles flat, cutting plates medially connected. Maxillary plates MxI, MxII, MxIV, MxV and MxVI (may be absent) paired, MxIII most frequently unpaired present on left side only; each species with limited variability in numbers of maxillary teeth. Branchiae present, usually pectinate with variable number of branchial filaments; limited to a number of chaetigers or present over a long body region. Parapodia with well- developed neuropodia; notopodia represented by bases of notopodial cirri. Ventral cirri usually with basal glandular inflated region at least in median chaetigers; distally tapering to distinct tips in most taxa, but tip may be missing. Notopodial cirri well developed in most cases. Internal notopodial aciculae present in many species, but often missing. Neuropodial aciculae single or multiple, distally often projecting from neuropodia; most commonly tapering to blunt straight tips, but distally bent, hammer-headed or otherwise modified in some species. Notopodial chaetae absent. Neuropodial chaetae in two distinct fascicles; supra-acicular fascicle located dorsal to neuroaciculae, consisting of limbate chaetae usually in two or more oblique rows and pectinate chaetae usually anterior or dorsal to limbate chaetae. Subacicular fascicle usually located ventral to neuroaciculae, consisting of true-compound falciger or spiniger chaetae sensu Zanol et al. (2014); usually arranged in two or more oblique rows, rarely in a single flattened fascicle. Chaetae composition usually similar in most chaetigers, but vary in shape and number along the body, often reduced in numbers in far posterior chaetigers. Appendages of compound falciger chaetae bidentate, in some species teeth inconspicuous. Subacicular hooks present from anteromedian chaetigers at ventral most end of parapodia; occurring singly (replacement hooks often visible) or as multiples; distally falcate or bidentate, dark (brown or black) with paired guards. Neuroaciculae and subacicular hooks and, rarely, shafts of compound falciger chaetae sclerotinized, brown or black. Dorsal pygidial cirri present; ventral pygidial cirri absent or present.

Remarks. Eunice was revised in Fauchald (1992), who discussed the designation of type species and briefly reviewed the history of the genus. Since then, the genus composition has changed because Leodice and Nicidion , previously synonymized with Eunice , have been revalidated ( Zanol et al. 2014). Thus, Eunice does not include species bearing at least one of the following features: prostomial appendage regularly articulated, lack of branchiae, tridentate subacicular hooks, light subacicular hooks or dark subacicular hooks with darkest portion at the distal half or close to the distal end, black dot between posterior parapodia. The definition of Eunice sensu stricto and its species composition is still not clear due to the inconsistent placement of the type species Eunice aphroditois ( Pallas, 1788) in phylogenetic hypotheses ( Struck et al. 2006; Zanol et al. 2007, 2010, 2014). Eunice still contains the remnant eunicid species that could not be assigned to any of the other recognized genera. This problem, however, does not influence the recognition of species.