Mooreonuphis nunezi, Arias, Andrés, 2016

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, Zootaxa 4168 (3), pp. 481-511 : 504-505

Mooreonuphis nunezi sp. nov.

Figures 14–15

Mooreonuphis sp. Arias & Paxton, 2015a.

Nothria geophiliformis .— López & San Martín, 1992. Not Moore, 1903.

Type material. Holotype ( MNCN 16.01 /3329) off shore near San Francisco beach (“ Praia Francisca”), 17° 12' N – 25° 12' W, Santa Luzia island , Cape Verde archipelago, West Africa, 50 m depth, coll. “ Primera Expedición Española a Cabo Verde” 22 Aug 1985 ; paratype (MNCN 16.01/3330; MNCN 16.01/17461) Curral Velho, 15° 59' N– 22° 54' W, Boavista island, Cape Verde archipelago, western Africa , 75 m depth, coll. “ Primera Expedición Española a Cabo Verde ” 26 Aug 1985.

Comparative material. Mooreonuphis vespa Holotype ( MNCN 16.01 /11013) Off Asturias, 43.80º N – 5.67 ºW, N. Spain, Cantabrian shelf, Bay of Biscay, eastern Atlantic , 152 m depth, coll. COCACE campaign.

Type locality. San Francisco beach (“ Praia Francisca”) 17° 12' N – 25° 12' W, 50 m depth, Santa Luzia island, Cape Verde archipelago, tropical eastern Atlantic .

Diagnosis. Body cream coloured with brown transverse band on peristomium. Antennae to chaetigers 4–5; palpophores and antennophores with 3–4 basal rings plus long distal ring, equal in length to all basal rings together. Peristomial cirri slender, not exceeding anterior margin of prostomium. First five pairs of parapodia modified, directed slightly anterolaterally with bi- and tridentate pseudocompound hooks and simple large median hook persisting to chaetiger 13. Spinigers from chaetiger 5–6 to 13–14, subacicular hooks from chaetiger 14–15. Flat pectinate chaetae with 9–10 teeth. First five chaetigers with subulate ventral cirri. Branchiae as single filament from chaetiger 29–30 continuing to end of incomplete types.

Description. Holotype incomplete, consisting of 179 chaetigers, 68 mm long and 1.9 mm wide. Paratype incomplete with 51 chaetigers, 17 mm in length, 1.4 mm in width.

Anterior end of body slender and nearly cylindrical, becoming broader and slightly depressed between chaetigers 8–10. Ethanol stored specimens cream coloured with a brown transverse dorsal pigment band on peristomium ( Fig. 14 A, B). Prostomium anteriorly weakly incised with frontal and upper lips stout and oval, latter without median section. Palps reaching chaetiger 1, lateral antennae reaching chaetiger 4–5, median antenna reaching chaetiger 4–5; antennae and palps with gradually tapering styles and ringed ceratophores with 3–4 basal rings and very long distal ring being equal to all basal rings together. Small eyespot between bases of palp and lateral antenna. Nuchal grooves straight with small middorsal separation laterally curving towards eyespots. Peristomium half as long as first chaetiger. Peristomial cirri slender, shorter than peristomium not exceeding anterior margin of prostomium, inserted distally on peristomium slightly lateral to lateral antennae.

Anterior chaetigers (1 to 4) subequal in length, longer than those following. First five pairs of parapodia modified, not enlarged, directed slightly anterolaterally, with prechaetal fold, triangular prechaetal lobe and long subulate postchaetal lobe ( Fig. 15 A). Prechaetal lobe becoming low by chaetiger 10, postchaetal lobe becoming successively shorter, reduced to small knob by chaetiger 15. Ventral cirri subulate on anterior five chaetigers, followed by transitory forms on chaetigers 6 and replaced by round glandular pads from chaetiger 7. Ventral glandular pads with irregular cuticular pore pattern ( Fig. 14 G). Dorsal cirri of modified parapodia slightly longer than postchaetal lobes ( Fig. 15 A). Branchiae as single filaments, strap-like, from chaetiger 29–30 to end of fragment; first branchiae (chaetigers 29–30 to 34–35) shorter than dorsal cirri, successively becoming longer, twice as long as dorsal cirrus by chaetiger 40 ( Fig. 15 B), not reaching the dorsal mid-line.

Aciculae yellowish with tapering distal ends ( Fig. 15 J), generally two per parapodium, from chaetiger 8 to 15 subdistally expanded into a flattened pad with tapered tips ( Fig. 15 K, L). First four chaetigers with following chaetal complement going from superior to inferior part of chaetal fan: one slender limbate chaeta, two to three long-appendaged bi- and/or tridentate pseudocompound hooks ( Fig. 15 C, D), one simple tridentate large median hook ( Fig. 15 F) and one to two short-appendaged tridentate pseudocompound hooks ( Fig. 15 E). Chaetiger 5 with three to four limbate chaetae, one to two short-appendage pseudocompound hooks, one simple tridentate large median hook and one to two spinigers. Appendages of both types of hooks gradually becoming shorter ( Fig. 15 G), appearance of short-appendaged pseudocompound hooks progressively resembling distal end of simple large median hook. Simple large median hook present until chaetiger 13, appearing paired in some anteriormost chaetigers of holotype. From chaetiger 5–6 to chaetiger 13 (right)–14 (left) in holotype (13 in paratype) simple limbate chaetae ( Fig. 14 F) and compound spinigers ( Fig. 15 H) replacing pseudocompound hooks. Bidentate subacicular hooded hooks replacing ventral spinigers from chaetiger 14 (right)–15 (left) in holotype (chaetiger 14 in paratype) to end of fragments ( Fig. 14 E). Flat pectinate chaetae with 9–10 teeth present from chaetiger 6, two per parapodium, anteriormost chaeta with combs parallel and wide shafts ( Figs 14 C, 15I), pectinate from median and posterior chaetigers with combs distally oblique, narrower stems and longer distal part ( Fig. 14 D).

Mandibles small in relation to maxillae, with white calcified cutting plates and slender shafts. Maxillae ( Fig. 15 M) weakly sclerotised; maxillary formula (based on paratype): Mx I = 1 + 1; Mx II = 9 + 8; Mx III = 7 + 0; Mx IV = 6 + 9; Mx V = 1+1. Mx VI absent. Tube cylindrical in shape, parchment-like and externally covered with sand-grains.

Etymology. It gives me great pleasure to dedicate this new species to Dr Jorge Núñez in recognition of his numerous studies on the Macaronesian polychaetes.

Distribution and ecology. Mooreonuphis nunezi sp. nov. is known from the shallow sandy bottoms (50 to 75 m depth) of the Cape Verde archipelago (tropical eastern Atlantic). This species was collected singly at two stations, indicating a very low population density and suggesting that it is apparently a very rare species with a restricted distribution in tropical West Africa. This is first confirmed record of the genus Mooreonuphis in Africa. Remarks. This study was initiated following the discovery of two Onuphis like specimens, labelled as Nothria geophiliformis and deposited in the Museo Nacional de Ciencias Naturales of Madrid as part of the polychaete material collected during the first Spanish expedition to Cape Verde archipelago (August 1985). After reexamination, it was observed that these specimens had compound limbate chaetae (=spinigers) in their anterior non modified parapodia, a diagnostic feature of species of the genus Mooreonuphis and thus they were referred as Moreonuphis sp. by Arias & Paxton (2015a). Mooreonuphis nunezi sp. nov. is the second species of its genus recorded in the eastern Atlantic to date. The other described E. Atlantic species, Mooreonuphis vespa Arias et al., 2013 , clearly differs from M. nunezi sp. nov. in having a characteristic colour pattern formed by segmental brown pigment bands on yellowish background, large median simple hooks restricted to the first five chaetigers and subacicular hooks starting from chaetiger 18–19.

Mooreonuphis nunezi sp. nov. is unique within its congeners by displaying a continuous distribution of large median simple hooks from the first chaetiger to the last chaetiger before the appearance of the subacicular hooks on chaetiger 14. Nevertheless, M. nunezi sp. nov. resembles Mooreonuphis jonesi Fauchald, 1982c and Mooreonuphis veleronis ( Fauchald, 1980) in the late origin of the single branchiae, starting in chaetigers 29–30 and in having expanded aciculae in anterior unmodified chaetigers. However, M. nunezi also differs from these two species by possessing bi- and tridentate pseudocompound hooks in the anterior five chaetigers, whilst M. jonesi and M. veleronis have only tridentate hooks in the first four and three chaetigers respectively ( Fauchald 1980; 1982c). Rullier (1964) reported Nothria stigmatis intermedia from Cape Verde and later Rullier’s records were referred as Mooreonuphis intermedia by Núñez et al. (1999) in an update of the polychaete checklist from Cape Verde. Rullier’s description of the specimens is brief and generic. He stated that they are consistent with the subspecies diagnosis made by Hartman (1944) but he noted that the specimens had a reddish-brownish colour pattern and this contrasts with the practical absence of colour pattern of M. nunezi sp. nov. Rullier's specimens were not available for examination and because of the colour difference (usually of diagnostic value in onuphids) they are herein considered as non conspecific with M. nunezi sp. nov. and thus they were not included to the list of synonyms of the new species.

Figures

FIGURE 14. Mooreonuphis nunezi sp. nov. Holotype A, B (MNCN 16.01 / 3329) photomicrographs, paratype C-G (MNCN 16.01 / 17461) scanning electron micrographs. A, anterior end, lateral view; B, anterior end, dorsal view; C, pectinate chaeta from chaetiger 8; D, pectinate chaeta from chaetiger 30; E, subacicular hook from chaetiger 25; F, limbate chaetae from chaetiger 20; G, glandular pad from median chaetiger.

FIGURE 15. Mooreonuphis nunezi sp. nov. Paratype (MNCN 16.01 / 3330). Line drawings. A, parapodium chaetiger 1, anterior view; B, parapodium chaetiger 34, anterior view; C, bidentate long-appendaged pseudocompound hook from chaetiger 1; D, tridentate long-appendaged pseudocompound hook from chaetiger 1; E, tridentate short-appendaged pseudocompound hook from chaetiger 2; F, simple large median hook from chaetiger 1; G, tridentate short-appendaged pseudocompound hook from chaetiger 5; H, compound limbate (= spiniger) from chaetiger 6; pectinate chaeta from the same; J, aciculae from chaetiger 1; K, aciculae from chaetiger 8; L, aciculae from chaetiger 14; M, maxillae.