Nephtyidae

Diagnosis. Elongate compact bodies with an eversible pharynx. Prostomium with a pair of palps, antennae present or absent, nuchal organs present at base of prostomium. Pharynx with terminal papillae, longitudinal rows of subterminal papillae present or absent, proximal surface may be smooth or covered with small verrucae, subterminal jaws present. Parapodia biramous, typically with well separated rami, with acicular, pre- and postchaetal lobes, and ventral and dorsal cirrus. Chaetae simple, often barred or spinose, lyrate chaetae present or absent, aciculae thick. Branchiae, when present, typically on the ventral margin of notopodia below dorsal cirrus occupying interramal space, and may be involute, straight or recurved. Terminal anus with single cirrus.

Remarks. The above definition is based on the description of the family given by Ravara et al. (2010 b). A combination of characters are used to distinguish between genera: the presence or absence of antennae, palps single or bifid, the shape of the nuchal organs or pits, the presence or absence of pharyngeal papillae, the number of pharyngeal jaws, the presence or absence of branchiae, the curvature of the branchiae, the degree of development of parapodial lobes, the shape of the acicular lobes, and the form of the preacicular chaetae (Ravara et al. 2010 a, Dnestrovskaya 2013). Species characters include the shape of the branchiae, the chaetiger corresponding to the beginning of the branchiae along the body, the number of pairs of branchiae, the number of rows of subterminal pharyngeal papillae, the number of pharyngeal papillae in each subterminal row, presence or absence of elongate middorsal and midventral papilla, presence or absence of pharyngeal verrucae, the presence of serrated and / or spinose chaetae, the presence or absence of lyrate chaetae (previously reported as a generic character by Dnestrovskaya 2013), lyrate chaetal shape, the shape of the dorsal and ventral cirri, and the shape of the distal end of the aciculae. The use of prostomium shape proposed by Ohwada (1985) has subsequently been dismissed as a useful character by various authors due to the highly “ plastic ” nature of the soft-tissue of the prostomium, as shape has been observed to depend on the extent of the eversion of the pharynx as well as the form and degree of fixation (Dnestrovskaya 2013; Dixon-Bridges et al. 2014). We have followed the chaetal terminology of Dnestrovkaya & Jirkov (2010, 2011) who recognise four main types: capillary, barred, chaetae with spines (spinose and / or serrated) and lyrate.