Key to adult species of Onuphis and Mooreonuphis from Europe to West Africa

1. Palpostyles longer than palpophores; compound ventral limbates (=spinigers) (Fig. 15 H) present in anterior non-modified chaetigers............................................................................. Mooreonuphis ...2

- Palpostyles shorter than palpophores (Figs 4 A, 13 A); compound limbate chaetae (=spinigers) absent in anterior non-modified chaetigers................................................................................... Onuphis ... 4

2. Banding colour pattern present on dorsum of segments; first five pairs of parapodia with tridentate pseudocompound hooks; SAHs from chaetiger 18–19........................................................ M. vespa Arias et al., 2013

- Banding colour pattern absent; first five pairs of parapodia with bi- and tridentate pseudocompound hooks; SAHs from chaetiger 14–15............................................................................. M. nunezi sp. nov.

4. Branchiae from chaetiger 1............................................................................. 5

- Branchiae from chaetiger 5, all branchiae simple and strap-like....................... O. farensis Gil & Machado, 2014

5. All branchiae simple and strap-like, colour pattern practically absent, first four pairs of parapodia with pseudocompound hooks.................................................................................................... 6

- Branchiae pectinate from 17th to 25th chaetiger, colour pattern present or absent, first two to three pairs of parapodia with pseudocompound hooks............................................................................... 7

6. Bi-, tri- and quatridentate pseudocompound hooks with falcate hoods, SAHs from chaetiger 9, subulate ventral cirri in first four chaetigers............................................................ O. anadonae Arias & Paxton, 2015

- Only tridentate pseudocompound hooks with moderately long, triangular and pointed hoods, SAH from chaetiger 14, subulate ventral cirri in first five to six chaetigers......................................... O. rullieriana (Amoureux, 1977)

7. First two pairs of parapodia with pseudocompound hooks...................................................... 8

- First three pairs of parapodia with pseudocompound hooks..................................................... 9

8. Colour pattern present, eyespots on prostomium present, pseudocompound hooks tridentate...................................................................................................... O. landanaensis Augener, 1918

- Colour pattern absent, eyespots on prostomium absent, pseudocompound hooks bi- and tridentate..... O. augeneri sp. nov.

9. Bi- and tridentate (or even multidentate) pseudocompound hooks, eyespots on prostomium absent, slender long appendaged pseudocompound hooks absent.......................................................................... 10

- Only tridentate pseudocompound hooks, eyespots on prostomium present, slender long appendaged pseudocompound hooks present.......................................................... O. eremita Audouin & Milne Edwards, 1833

10. Interramal papillae at base of dorsal cirrus on anterior non-modified chaetigers present, two or more branchial filaments from chaetiger 20–25, large and robust species............................................. O. pancerii Claparède, 1868

- Interramal papillae at base of dorsal cirrus on anterior non modified chaetigers absent, two or more branchial filaments from chaetiger 17–22, small and slender species.............................................. O. hanneloreae sp. nov.