Onuphis augeneri Arias, 2016, sp. nov.
Creators: name: Arias, Andrés
Publisher: name: Zenodo
Year: 2016
Subjects: Biodiversity
Taxonomy
Animalia
Annelida
Polychaeta
Eunicida
Onuphidae
Onuphis
Onuphis augeneri

description: Onuphis augeneri sp. nov.
Figures 2 A, B, 4–6; Tables 1, 2
Onuphis landanaensis Augener, 1918 (in part): 339–343.
Type material. Holotype (ZMH V.868), Nyanga river (Nyanga-Fluss), Gabon, West Africa, 11 m depth on soft bottom (6 fd. weicher Grund), coll. A. Hupfer (prior to 1917; four paratypes (ZMH P 27820; ZMH P 27821), same data as holotype, one coated with gold for SEM studies (ZMH P 27821).
Comparative material. Type material. Onuphis eremita Neotype (MNHN TYPE 1555) La Rochelle, France, eastern Atlantic, 46°09’N, 01°09’W –46°09’N, 01°10’W, intertidal sands, coll. 28 Sep 2011; Onuphis pancerii Neotype (MNCN 16.01 /311) Naples, Italy, specimen Num. 173 from the Collection of Rioja, 1894-1917.
Type locality. Off Nyanga estuary, on sandy substrate at 11 m depth, Gabon, West Africa, eastern Atlantic.
Diagnosis. Prostomium anteriorly extended with large frontal lips. Palps reaching chaetiger 2–3, lateral antennae reaching chaetiger 10–15 and median antenna chaetiger 3–4. Ceratophores long and strongly ringed, palpophores with 13–16 rings, lateral antennophores with 16–23 and median antennophore with 8–10 rings. Subulate ventral cirri in first six chaetigers; distinct subulate postchaetal lobes in first 9–10 chaetigers. Interramal papilla at base of dorsal cirrus absent. Bi- and tridentate pseudocompound long and short appendaged hooks in first two chaetigers; slender long-appendaged hook present. Subacicular hooks from chaetiger 9. Flat, distally oblique pectinate chaetae with 9–10 teeth from chaetiger 9–13, usually one per parapodium. Single branchial filaments from chaetiger 1 to 19–20, thereafter number increasing rapidly to maximum of three to four. Colour pattern absent.
Description. Small and slender species. All type specimens incomplete. Length of holotype 8.2 mm for 42 chaetigers, width 1.0 mm; paratypes ranging from 9.5 to 12.0 mm in length (42–53 chaetigers) and from 0.7 to 0.9 mm in width.
Anterior end of body nearly cylindrical, becoming broader and slightly depressed by chaetiger 15. Colour pattern absent in ethanol preserved specimens, body whitish and highly iridescent (Fig. 2 A). Methyl blue stained specimens with dotted line at anterior end of dorsum of each segment (Fig. 2 B). Prostomium subtriangular with pair of large subconical frontal lips (Fig. 4 A). Eyespots absent. Palps reaching chaetiger 2–3 with 12–15 basal rings and longer distal one. Lateral antennae reaching chaetiger 10–15 with 15–22 basal rings, median antenna reaching chaetiger 3–4 with 7–9 basal rings, all three antennophores with longer distal ring (Fig. 5 A). Palpostyles and antennostyles with irregular longitudinal rows of scarce and very inconspicuous sensory buds (Fig. 5 B, C). Nuchal grooves straight with narrow middorsal separation. Peristomial cirri inserted distally on peristomium slightly lateral to lateral antennae, longer than peristomium, not exceeding anterior margin of prostomium (Fig. 5 A).
First three chaetigers slightly longer than those following (Figs 2 A, 5 A). First three pairs of parapodia modified, not enlarged, directed slightly anterolaterally, with low prechaetal fold, distally rounded prechaetal lobe and spindle-shaped postchaetal lobe, longer than base of parapodium; digitate dorsal cirrus about as long as postchaetal lobe and slightly shorter ventral cirrus (Fig. 4 B, C). Subulate ventral cirri in first six chaetigers, followed by transitory forms on chaetiger 7 and pad-like thereafter (Fig. 5 A). Ventral glandular pads with irregular cuticular pore pattern (Fig. 5 D). Postchaetal lobe as distinct subulate lobe in first 9–10 chaetigers, becoming smaller and conical in shape thereafter. Interramal papilla at base of dorsal cirrus absent. Parapodia of anterior and medial chaetigers with high density of sensory buds.
Continued.
No
., number; PCH, pseudocompound hook; SAH, subacicular hook; VC, ventral cirrus
Branchiae as single filament from first chaetiger to chaetiger 19–20 (Fig. 4 B), then number of filaments increasing rapidly to maximum of three to four in pectinate arrangement over chaetiger 40 (Fig. 5 E); by chaetiger 50 diminishing in number and getting smaller and becoming simple again in posterior chaetigers.
Aciculae yellowish with pointed tips, usually three per parapodium. Hooded pseudocompound hooks in first two chaetigers. First two parapodia (Fig. 4 B, C) with following chaetal complement from superior to inferior part of chaetal fan: one to two simple chaetae (capillary), three protruding distal tips of aciculae, two to three slender long-appendaged bi- and/or tridentate pseudocompound hooks (Figs 4 G, 6 A, B), two to three more robust shortappendaged bi- and tridentate pseudocompound hooks (Figs 4 D-F, 6 A, B). Hoods of pseudocompound hooks falcate with pointed tip (Fig. 6 C, D). Pseudocompound hooks replaced by limbate chaetae from chaetiger 3 (Figs 4 C, 6E). Hooded bidentate subacicular hooks from chaetiger 9 (Fig. 6 G, H). Pectinate chaetae flat and slightly oblique with 9–10 teeth, usually single, present from chaetiger 9 (Fig. 6 F). Mandibles translucent with weakly calcified cutting plates and slender shafts. Maxillae (Fig. 4 H) weakly sclerotised; maxillary formula: Mx I = 1 + 1, Mx II = 8 + 8, Mx III = 7 + 0, Mx IV = 6 + 9, Mx V = 1 + 1, Mx VI absent.
Etymology. The new species is named in honour of the late Dr Hermann Augener who studied the specimens originally.
Distribution and ecology. Onuphis augeneri sp. nov. is known from the shallow subtidal sandy bottoms (about 10 m depth) of the mouth of the Nyanga estuary in Gabon, West Africa, tropical eastern Atlantic (Fig. 1).
Remarks. Onuphis augeneri sp. nov. shares a number of significant features (e.g. an anteriorly extended prostomium with the subulate frontal lips arising from the slopes of the apex; palps and antennae with usually more than 15 ceratophoral rings; simple branchiae from chaetiger 1, branching from about chaetiger 20 and reaching several filaments; subulate ventral cirri on more than the usual number of anterior modified chaetigers) with the nominal species, and thus is herein considered as a member of the O. eremita species complex (see Table 1 for comparison between eastern Atlantic members of the O. eremita complex). Onuphis augeneri sp. nov. resembles O. landanaensis and O. texana Fauchald, 1982b in having only two anterior chaetigers with pseudocompound hooks. However, it can be separated from O. landanaensis and O. texana by having bi- and tridentate pseudocompound hooks (while they are only tridentate in O. landanaensis and only bidentate in O. texana); furthermore, absence of eyespots on the prostomium and lack of a pigmented colour pattern on the dorsum, both features present in O. landanaensis and O. texana (Table 2).
description: Published as part of Arias, Andrés, 2016, Onuphi s and Mooreonuphis (Annelida: Onuphidae) from West Africa with the description of three new species and the reinstatement of O. landanaensis Augener, 1918, pp. 481-511 in Zootaxa 4168 (3) on pages 485-487, DOI: 10.11646/zootaxa.4168.3.3, http://zenodo.org/record/155271