Marphysa zanolae, Lavesque & Daffe & Glasby & Hourdez & Hutchings, 2022

Lavesque, Nicolas, Daffe, Guillemine, Glasby, Christopher, Hourdez, Stephane & Hutchings, Pat, 2022, Three new deep-sea species of Marphysa (Annelida, Eunicida, Eunicidae) from Papua New Guinea (Bismarck and Solomon seas), ZooKeys 1122, pp. 81-105 : 81

Marphysa zanolae sp. nov.

Figs 8 , 9

Material examined.

Holotype: MNHN-IA-2015-1519, entire, few parapodia used for molecular analysis, South Pacific Ocean , Papua New Guinea, New Ireland, CP4260, - 2.9°S, 151.1°E, depth 350-847 m, April 2014 . Paratype: MNHN-IA-2015-1607, anterior part only, South Pacific Ocean , Papua New Guinea, New Britain, CP4266, - 4.616°S, 152.25°E, depth 575-616 m, April 2014 .

Description

(based on holotype, with variation in parentheses for paratype). Preserved specimens 197 (85 ant. part only) chaetigers, 101 mm (36 mm) long, 4.1 mm (2.8 mm) wide at chaetiger 10, excluding parapodia. Body elongated, slightly tapering at posterior end.

Prostomium strongly bilobed with two dorsoventrally flattened buccal lips and an anterior notch between them (Fig. 8B, C ). Two palps and three antennae slender and tapering, arranged in an arc on posterior margin of prostomium. Antennae more or less smooth, of equal length, shorter than prostomium (slightly longer for PNG012), slightly longer than palps (palps very short for paratype PNG12, but probably broken) (Fig. 8C ). Eyes absent. First peristomial ring approximately the same size as second one dorsally (Fig. 8C ).

Maxillary apparatus yellow to golden brown, partially everted in holotype and paratype. Maxillae with carriers and four paired elements and one single one, formula as follows (Fig. 9F ): MF = 1+1, 4+4, 5+0, 3+6, 1+1. MI ~ 2 × longer than maxillary carrier, rectangular anteriorly, triangular posteriorly, with a pair of oval wings situated at posterolateral margins. MI forceps-like, without attachment lamellae; well-developed falcal arch. Closing system ~ 4-5 × shorter than MI. MII wide, without attachment lamella, teeth triangular, recurved, and distributed in less than half of plate length. Ligament between MII and MIII absent (or not sclerotized). MIII, single, slightly shorter than right MIV, curved forming part of distal arc; with left four teeth recurved, equal-sized and triangular, two right teeth shorter and blunt, without attachment lamella. Left MIV short (half the size of right MIV) with wide, triangular base, left 2 teeth longer than right-most one; attachment lamella dark, semi-circular. Right MIV with teeth triangular, recurved, decreasing in size posteriorly; attachment lamella large, wide, best developed centrally. MV, paired, rectangular (longer than wide), with a broad cutting edge, and no clearly defined teeth (but following tradition to score as 1+1). Mandibles (Fig. 9G ) yellow to golden brown, slightly shorter than MI plus carriers; cutting plates whitish, with distinct growth rings.

First two parapodia located below middle line of body wall, but gradually positioned dorsally to approximately midline in subsequent segments (Fig. 8A ). Notopodial cirri with large base and slender, tapering tip from anterior to mid-body chaetigers, digitiform cirri in posterior chaetigers; same size as neuropodial cirri, but shorter than post-chaetal lobe in anterior chaetigers (Fig. 9A-C ). Chaetal lobes comprising a low pre-chaetal lip and a large tongue-like post-chaetal lobe from first chaetiger to approximately chaetiger 25, almost inconspicuous thereafter. Ventral cirri bluntly conical until chaetiger 25, digitiform with bulbous base thereafter (Fig. 9A-C ).

Branchiae with a long single filament (Figs 8A , 9B ), commencing from chaetiger 31 (32) and continuing to mid-body (i.e., chaetiger 118 for holotype).

Aciculae black with paler blunt tips, ~ four per parapodium in anterior chaetigers, two or three per parapodium in middle chaetigers, and one or two per parapodium in posterior chaetigers. Supra-acicular chaetae with limbate capillaries and pectinates; capillaries present from first chaetiger to near pygidium, numbering up to 20 in anterior chaetigers. Pectinate chaetae commencing from first few chaetigers to near end, one type only (Fig. 9H, I ), with two or three pectinate chaetae per parapodium in anterior body, up to seven from posterior chaetigers, isodont-wide-thick (IWT) having 11-20 long teeth (Fig. 9H, I ).

Subacicular chaetae compound falcigers and subacicular hooks (Fig. 9D, E ). Compound falcigers bidentate, with long blades and short teeth, commencing from first chaetiger to near pygidium, with more than 30 chaetae within a parapodium in anterior part, with ~ 20 chaetae in mid-body and ~ 5-7 in last chaetigers (Fig. 9D ). Subacicular hooks amber to black, with much paler tip, commencing from anterior chaetiger 28 (chaetiger 30) to near end, one per parapodium in anterior and posterior parts, few chaetigers with two hooks in middle body; slightly thinner than aciculae; subacicular hooks unidentate, with blunt tip (Fig. 9E ).

Pygidium round, dorsally positioned, with two pairs of tapering pygidial cirri attached at ventral edge, dorsal pair 3 × length of ventral pair (Fig. 8D ).

Etymology.

This species is dedicated to Joana Zanol for her great contributions to the knowledge of Eunicidae and Marphysa , and her friendship to PH.

Type locality.

Solomon Sea, Papua New Guinea, New Britain and New Ireland.

Distribution.

Only known from type locality.

Habitat.

Between 350 to 616 m depth, among pumice rocks, inside sunken wood.

Remarks.

Within the Central Indo-Pacific Realm, only one species having only compound falcigers present and branchiae present in a long region (group C2) occurs: M. soembaensis Augener, 1933 (type locality in Pulau Sumba, South Indonesia). However, this species differs from M. zanolae sp. nov. by the presence of poorly developed branchiae with two or three branchial filaments instead of well-developed branchiae with a single long filament only for M. zanolae sp. nov. These branchiae start from chaetiger 40 for M. soembaensis and from chaetiger 31 for M. zanolae . Moreover, M. soembaensis has bidentate subacicular hooks while they are unidentate for M. zanolae sp. nov. Finally, M. zanolae sp. nov. has pectinate chaetae with very long outer teeth, which are not present in M. soembaensis . The blade of the compound falcigers is very short for M. soembaensis compared to those of M. zanolae sp. nov. Finally, specimens of M. soembaensis were sampled intertidally in a bay in Indonesia while M. zanolae sp. nov. occurs in deep-sea environments in Papua New Guinea.

Figures

Figure 8. Marphysa zanolae sp. nov. holotype MNHN-IA- 2015 - 1519 (A, C, D), paratype MNHN-IA- 2015 - 1607 (B): A anterior end, lateral view B anterior end, ventral view C anterior end lateral view D pygidium.

Figure 9. Marphysa zanolae sp. nov. holotype MNHN-IA- 2015 - 1519 (A-E), paratype MNHN-IA- 2015 - 1607 (F, G): A parapodia from anterior body (chaetiger 8) B parapodia from mid-body (chaetiger 31) C parapodia from posterior body D compound falcigers from anterior chaetiger (chaetiger 12) E subacicular hook from mid-body (chaetiger 43) F maxilla, dorsal view G mandibles, dorsal view H pectinate chaeta, chaetiger 48 I pectinate chaeta, chaetiger 33. Abbreviations: MI to MV, maxillae I to V; Ac, aciculae; Bf, branchial filament; Cp, cutting plate; Fil, filament; IWT, isodont-wide-thick; Mc, maxillary carrier; Nc, notopodial cirri; Sah, subacicular hook; Vc, ventral cirri. A-C Sah and Ac are illustrated schematically to indicate position.