Marphysa banana, Lavesque & Daffe & Glasby & Hourdez & Hutchings, 2022
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publication ID |
https://dx.doi.org/10.3897/zookeys.1122.89990 |
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publication LSID |
lsid:zoobank.org:pub:0DF18698-843E-4F78-9360-58A46B2010F7 |
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persistent identifier |
https://treatment.plazi.org/id/36B09BD6-2080-4266-9945-98EA1CA40913 |
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taxon LSID |
lsid:zoobank.org:act:36B09BD6-2080-4266-9945-98EA1CA40913 |
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treatment provided by |
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scientific name |
Marphysa banana |
| status |
sp. nov. |
Marphysa banana sp. nov.
Figs 2 View Figure 2 , 3 View Figure 3 , 4 View Figure 4
Material examined.
Holotype: MNHN-IA-2015-1608, complete. Paratypes: AM W.53773, complete; AM W.53774, complete, some parapodia mounted for SEM; MNHN-IA-2021-725, anterior part only. All material collected from South Pacific Ocean , Papua New Guinea, New Ireland, CP4254, - 2.483°S, 150.66°E, depth 273-324 m, April 2014 GoogleMaps .
Description
(based on holotype, with variation in parentheses for paratypes). Preserved specimens strongly iridescent (Fig. 2A, C, D View Figure 2 ), ~ 230 (220) chaetigers, 112 mm (71-157) long, 3.3 mm (2.1-5.4) width at chaetiger 10, excluding parapodia. Body elongated and tapered gradually at posterior end (Fig. 2B View Figure 2 ).
Prostomium rounded anteriorly with two dorsoventrally flattened buccal lips an anterior notch between them, notch more visible ventrally (Fig. 2A, C, D View Figure 2 ). 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, longer than palps (same size), shorter (same size) than prostomium (Fig. 2C View Figure 2 ). Eyes present, one pair, brownish, very faint, present at posterior base between palps and lateral antennae. First peristomial ring ~ 3 × longer than second one dorsally (Fig. 2C View Figure 2 ).
Maxillary apparatus (Fig. 3D, E View Figure 3 ) partially everted in holotype or paratypes. Formula as follows: MF = 1+1, 5+5, 6+0, 4+9, 1+1. MI ~ 2 × longer than maxillary carrier, rectangular anteriorly, triangular posteriorly, with a pair of rounded wings situated at posterolateral margins. MI forceps-like, without attachment lamellae, sub-right-angle falcal arch. Closing system ~ 4 × shorter than MI. Ligament between MI and MII golden. MII without attachment lamella, teeth triangular, distributed in less than half of plate length. Ligament between MII and MIII absent (or not sclerotized). MIII, single, longer than left MIV, curved, with equal-sized triangular teeth; short attachment lamella situated in the centre of posterior edge of maxilla, thin, dark. Left MIV short (less than half the size of right MIV) with wide, rounded base, left-most teeth longer than right-most ones; attachment lamella dark, semi-circular. Right MIV long, with teeth triangular, decreasing in size posteriorly; attachment lamella wide, semi-circular, dark. MV, paired, as long as high, with a dorsal curved tooth. Mandibles light brown, concentric stripes not visible; longer than MI; cutting plates whitish, without dorsal teeth (Fig. 3E View Figure 3 ).
First few parapodia located below middle line of body wall, but gradually positioned dorsally to approximately midline in subsequent segments (Fig. 2A View Figure 2 ). Notopodial cirri slender, tapering, slightly longer than ventral cirri, thinner posteriorly (Fig. 3A-C View Figure 3 ). Chaetal lobes comprising a low pre-chaetal lip and a globular post-chaetal lobe. Ventral cirri bluntly conical, with rounded tip, shorter than post-chaetal lobes anteriorly, thereafter slightly longer than post-chaetal lobes (Fig. 3A-C View Figure 3 ). Branchiae pectinate, commencing from chaetiger 20 (18-19) and continuing to near end, very short anteriorly, longer in medium chaetigers but not reaching mid-dorsal line; number of filaments increasing from 1-3 anteriorly to 4-6 in mid-body, decreasing to 3-4 in last several chaetigers (Figs 2E View Figure 2 , 3A-C View Figure 3 ).
Aciculae black with paler blunt tips, approximately three or four per parapodium in anterior chaetigers, one or two per parapodium in middle chaetigers, and one 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 (Fig. 3A-C View Figure 3 ).
Pectinate chaetae commencing from approximately chaetiger 20 to near end, three types identified. Type 1 from anterior parapodia to mid-body: isodont-narrow-slender (INS), having ~ 20 short internal teeth, each tooth prolonged by a thin filament (Fig. 4A, B View Figure 4 ). Types 2 and 3 from posterior parapodia only (Fig. 4C, D View Figure 4 ): type 2 asymmetrical, anodont-wide-thick (AWT), having ~ 10 thick internal teeth, each tooth prolonged by a thin filament; type 3 asymmetrical, anodont-wide-slender (AWS), having ~ 20 internal teeth, each tooth prolonged by a thin filament (Fig. 4D View Figure 4 ).
Subacicular chaetae with compound spinigers and subacicular hooks (Fig. 3F View Figure 3 ). Compound spinigers commencing from first chaetiger to near pygidium, with long, tapered blade. Subacicular hooks transparent, commencing from anterior chaetigers 43-52 (range for type material) to near end and inferior to bundle of spinigers, one per parapodium; much thinner than aciculae; subacicular hooks bidentate (Fig. 3F View Figure 3 ).
Pygidium round, with crenulated margin, dorsally positioned, with two pairs of tapering pygidial cirri attached at ventral edge, dorsal pair 2-3 × length of ventral pair (Fig. 2B View Figure 2 ).
Etymology.
The species name refers to the decomposing banana leaves among which all the specimens were found.
Type locality.
South Pacific, Papua New Guinea, New Ireland.
Distribution.
Only known from type locality.
Habitat.
Between 273 and 324 m, found inside banana leaves that presumably have been entrained from river runoff via coastal waters.
Remarks.
With the presence of compound spinigers only and the branchiae present over many chaetigers Marphysa banana sp. nov. belongs to the group B2, also known as the Nereis sanguinea -group Quatrefages, 1866. Among the nine species of this group occurring in the Central Indo-Pacific Realm, M. banana sp. nov. is similar to M. hongkongensa , M. iloiloensis , and M. mullawa by the presence of subacicular hooks starting from chaetigers 30-50 and the branchiae commencing from chaetigers 14-20.
However, M. banana sp. nov. differs from M. hongkongensa by the presence of pectinate chaetae starting from around chaetiger 20 instead of starting from the first few chaetigers as found for M. hongkongensa ; and by the presence of three different types of pectinate chaetae instead of four types as found in M. hongkongensa . Moreover, M. banana sp. nov. has eyes whereas M. hongkongensa does not have any. The subacicular hooks of M. banana sp. nov. are bidentate while those of M. hongkongensa are unidentate and the maximum number of branchial filaments reaches six for M. banana sp. nov., while it can be ten for M. hongkongensa . Finally, M. hongkongensa lives in the lower intertidal of the Hong Kong region, while M. banana sp. nov. is a deep-sea species found inside banana leaves.
Marphysa banana sp. nov. differs from M. iloiloensis by the presence of four and nine teeth on the maxillary MIV, while M. iloiloensis has three and five teeth respectively. The two species show three different types of pectinate chaetae but not the same ones, as M. banana sp. nov. has INS, AWT and AWS with the first ones starting from chaetiger 20 while M. iloiloensis has INS, IWS and ANT, with first ones commencing from the first few chaetigers. The subacicular hooks are also different as they are bidentate for M. banana sp. nov. and unidentate for M. iloiloensis . Finally, M. iloiloensis lives in the brackish waters of the Philippines region, which is a very different habitat from the deep-sea habitat of M. banana sp. nov.
Marphysa banana sp. nov. differs from M. mullawa by the presence of pectinate chaetae starting from around chaetiger 20 instead of commencing from the first few chaetigers for M. mullawa , and the anterior chaetae numbering ~ 20 internal teeth instead of 10 for M. mullawa . The two species differ by their maxillary formulae, especially for maxillary MII (7+7 for M. mullawa , 5+5 for M. banana sp. nov.) and MIII (8+0 for M. mullawa , 6+0 for M. banana sp. nov.). Another difference concerns the shape of anterior branchiae, which are palmate for M. mullawa and pectinate for M. banana sp. nov. Once again, the two species live in very different habitats as M. mullawa is found in intertidal and shallow waters only, on mud or in seagrass beds.
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