Marphysa baudini, Lavesque & Zanol & Daffe & Flaxman & Hutchings, 2023

Lavesque, Nicolas, Zanol, Joana, Daffe, Guillemine, Flaxman, Beth & Hutchings, Pat, 2023, Two new species of Marphysa (Annelida, Eunicidae) from southern Australia., Zootaxa 5277 (1), pp. 113-130 : 117-122

publication ID	https://doi.org/ 10.11646/zootaxa.5277.1.5
publication LSID	lsid:zoobank.org:pub:8FF89CF0-E400-4C0E-BA2B-31CD6C068350
DOI	https://doi.org/10.5281/zenodo.7893005
persistent identifier	https://treatment.plazi.org/id/6EC295A7-C367-423B-9704-B27CAF0980F9
taxon LSID	lsid:zoobank.org:act:6EC295A7-C367-423B-9704-B27CAF0980F9
treatment provided by	Plazi
scientific name	Marphysa baudini
status	sp. nov.

Treatment

Marphysa baudini View in CoL n. sp.

Figures 1–3 View FIGURE 1 View FIGURE 2 View FIGURE 3 (A–C), 4 (A–C)

LSIDurn:lsid:zoobank.org:act: 6EC295A7-C367-423B-9704-B27CAF0980F9

Material examined. Holotype. AM W.35513, complete, some chaetigers mounted for SEM . Paratype. AM W.37251, incomplete, two parts. All material collected from South Australia, Adelaide, Port River , - 34.771001° S 138.5150° E, intertidal, March 2007 GoogleMaps .

Description (based on holotype, with variation in parentheses for paratypes). Preserved specimens whitish ( Fig. 1A View FIGURE 1 ), about 285 (143, incomplete) chaetigers, about 116 mm (106, incomplete) long, 6 mm (9.5 mm) width at chaetiger 10, excluding parapodia. Body round in cross section at anterior and middle regions, dorsoventrally flattened thereafter.

Prostomium strongly bilobed, with an anterior notch, dorsally flat, anteriorly rounded ( Fig. 1B View FIGURE 1 ). Palps and antennae arranged in an arc on posterior margin of prostomium. Median antenna isolated by gap from lateral antennae and palps. Median antenna slightly shorter than lateral ones, lateral antennae slightly longer than palps, antennae and palps longer than prostomium ( Fig. 1A–B View FIGURE 1 ). Median and lateral antennae reach back to chaetiger 2 and palps to chaetiger 1. Ceratostyles and palpostyles slender and tapering, all with indistinct cylindrical articulations. Ceratophores cylindrical (ring-shaped) and palpophores ring shaped. Prostomial appendage peduncles absent. Eyes present, one pair, black, present at posterior base between palps and lateral to lateral antennae. Separation between both peristomial rings distinct on all sides. First peristomial ring twice as long as second one dorsally ( Fig. 1A–B View FIGURE 1 ).

Maxillary formula as follows: MF = 1+1, 5+5, 7+0, 3+7, 1+1, MVI absent. Maxillary carrier approximately 2.5 times shorter than MI, rectangular anteriorly, triangular posteriorly, with a pair of rounded wings situated at posterolateral margins. MI forceps-like, without attachment lamellae, falcal arch extended at sub-right-angle, basal outer edge arched. Closing system approximately 4 times shorter than MI. Ligament between MI and MII light brown. MII without attachment lamella, teeth triangular, distributed in less than half of plate length. Ligament between MII and MIII light brown. MIII, single, longer than left MIV, slightly curved, with equal-sized triangular teeth, without attachment lamella. Left MIV short (less than half the size of right MIV), attachment lamella dark, curved. Right MIV long, with teeth triangular, decreasing in size posteriorly; attachment lamella curved, dark. MV, paired, longer than high ( Fig. 1C View FIGURE 1 ). Mandibles dark brown, with concentric stripes; longer than MI; cutting plates whitish.

First few parapodia located below ventro-laterally, but gradually positioned dorso-laterally in subsequent segments ( Fig. 1A View FIGURE 1 ). Chaetal lobes rounded in all chaetigers ( Fig. 4A–C View FIGURE 4 ). Pre-chaetal lobe shorter than chaetal lobe along the whole body ( Fig. 4A–C View FIGURE 4 ). Post-chaetal lobe longer than chaetal lobe in anterior chaetigers, shorter from mid body onwards ( Fig. 4A–C View FIGURE 4 ). Post-chaetal lobe digitiform in first three chaetigers, conical on chaetigers 4 to 7 ( Fig. 1B View FIGURE 1 ), wide and rounded thereafter ( Fig. 4A View FIGURE 4 ), post-chaetal lobe shorter than chaetal lobe in median and posterior chaetigers ( Fig. 4A–C View FIGURE 4 ). Dorsal cirri slender, tapering, longer than chaetal lobe anteriorly, as long as or shorter from mid body, longer in posterior most chaetigers ( Figs 3A–C View FIGURE 3 ; 4A–C View FIGURE 4 ). Ventral cirri shorter than dorsal cirri in anterior and mid body, becoming longer in posterior-most chaetigers ( Fig. 4C View FIGURE 4 ). Ventral cirri thumb-shaped with round wide tips in first chaetigers, from chaetiger 8, basally inflated with tapering to digitiform tip and rounded inflated base, tapering to wide tip from chaetiger 150 ( Figs 3A–C View FIGURE 3 ; 4B–C View FIGURE 4 ). Branchiae pectinate, commencing from chaetiger 25 (31) and continuing to near end (40 last chaetigers without branchiae), branchial filament 8 times longer than dorsal cirri where best developed; number of filaments increasing from two anteriorly to four in mid-body, decreasing to one in last several chaetigers ( Fig. 1A, D View FIGURE 1 ).

Notoaciculae absent in anterior and posterior most parapodia, present in median parapodia. Neurochaetal lobe round (truncate) in anterior half, pointed thereafter. Neuroaciculae black along most of the body, light brown in posterior-most parapodia; approximately 3–5 per parapodium in anterior and middle chaetigers, and 1–2 per parapodium in posterior chaetigers ( Fig. 3A–C View FIGURE 3 ). Supra-acicular chaetae with limbate capillaries and pectinates; capillaries present from chaetiger 1 to near pygidium, numbering up to 30 in anterior chaetigers ( Fig. 2A View FIGURE 2 ). Four types of pectinate chaetae identified. Type 1: thin, narrow heterodont with about 15–20 short and slender internal teeth, outer teeth longer, but with different length ( Fig. 2D View FIGURE 2 ), present from anterior body only. Type 2: thick, wide isodont with about 20–25 short and slender teeth, outer teeth longer and with the same length ( Fig. 2E–F View FIGURE 2 ), present from mid-body to the end. Type 3: thick, wide anodont with about 10 long and slender internal teeth, present from mid-body to the end ( Fig. 2F View FIGURE 2 ). Type 4: thick, wide anodont, with 3–5 internal long and thick teeth, oblique, present from mid-body to the end ( Fig. 2E–F View FIGURE 2 ). Subacicular chaetae with compound spinigers and subacicular hooks ( Fig. 2E–F View FIGURE 2 ). Compound spinigers commencing from chaetiger 1 to near pygidium, shaft slightly serrated, numbering up to 55 in anterior chaetigers ( Fig. 2A View FIGURE 2 ). Subacicular hooks dark yellow, commencing from chaetiger 41 and present in all chaetigers thereafter, ventral to bundle of falcigers, one per parapodium, rarely two; subacicular hooks unidentate in anterior part, bidentate from mid-body ( Fig. 2C View FIGURE 2 ).

Pygidium with crenulated margin, with two pairs of tapering pygidial cirri attached to ventral side of pygidium, dorsal pair about six times longer than ventral one ( Fig. 1E View FIGURE 1 ).

Etymology. This species is named after the French explorer Nicolas Baudin, captain of “ Le Géographe ” and “ Le Naturaliste ” ships, who explored in 1801–1802 a large southern part of Australia where many species of the biota were collected. This expedition was able to collect and describe many new species of plants and animals and was one of the greatest scientific journeys of all time with material being lodged in MNHN-Paris.

Type locality. South Pacific, South Australia, Adelaide, Port River .

Distribution. Known only from type locality.

Habitat. Intertidal, sandy mud.

Remarks. With the presence of compound spiniger chaetae along the whole body and branchiae along most of the body, Marphysa baudini n. sp. belongs to the Sanguinea-group ( Glasby & Hutchings, 2010). In Australia, three species belonging to this group occur: M. fauchaldi , M. kristiani , and M. mullawa .

Marphysa baudini n. sp. is characterised by having ventral cirri with inflated base and digitiform tip while they are broad and triangular for M. fauchaldi and thumb-shaped for M. mullawa . Thick, wide anodont pectinate chaetae, with 3–5 internal long and thick teeth (type 4) are present for Marphysa baudini n. sp. but absent in the three other species. Marphysa fauchaldi and M. kristiani have prostomial appendages peduncles which are absent in Marphysa baudini n. sp. Marphysa baudini n. sp. has compound spinigers present along the whole body while they are restricted in anterior chaetigers only in M. fauchaldi . Finally, Marphysa baudini n. sp. has eyes which are absent in M. kristiani .

In regions close to Australia, three other species belonging to the Sanguinea-group have been described: Marphysa banana Lavesque, Daffe, Glasby, Hourdez & Hutchings, 2022 (type locality: Papua New Guinea), Marphysa iloiloensis Glasby, Mandario, Burghardt, Kupriyanova, Gunton & Hutchings, 2019 (type locality: Philippines) and Marphysa teretiuscula ( Schmarda, 1861) (type locality: Sri Lanka). Firstly, M. baudini n. sp. differs from M. banana by the length of the branchial filaments, they are short for M. banana (3x longer than notopodial cirri) and long M. baudini n. sp. (8x longer than the cirri). The antennae are shorter than prostomium for M. banana and longer for M. baudini n. sp. Pectinate chaetae are present from the first few chaetigers for M. baudini n. sp. and from about chaetiger 20 for M. banana . M. baudini n. sp. has four different types of pectinate chaetae instead of three present in M. banana . The two species have thick, wide anodont pectinate chaetae (type 4), but those of M. baudini n. sp. have 3–4 thick internal teeth, while M. banana has10 shorter teeth. Marphysa banana has conical ventral cirri while they have inflated base and digitiform tips in M. baudini n. sp. Finally, M. baudini n. sp. lives in intertidal areas in South Australia while M. banana is a deep-sea species found inside banana leaves in Papua New Guinea.

Marphysa baudini n. sp. differs from M. iloiloensis by the numbers of different types of pectinate chaetae as M. iloiloensis lacks the thick, wide anodont pectinate chaetae. Marphysa iloiloensis has blunt conical ventral cirri in anterior (from CH 8) and median chaetigers while in the same region of M. baudini n. sp., ventral cirri have inflated bases and digitiform tips. Finally, the anterior post-chaetal lobes are digitiform in the first three chaetigers, conical on chaetigers 4 to 7, wide and rounded thereafter for M. baudini n. sp. while they are tongue-like for M. iloiloensis .

Marphysa teretiuscula (redescription in Molina-Acevedo & Idris 2021) is the most similar species to Marphysa baudini n. sp. However, M. teretiuscula has an inconspicuous and poorly developed falcal arch (Molina-Acevedo, personal communication), teeth restricted to the anteriormost one third of the MII, and reddish neuroaciculae with distal translucent tips. Also, it lacks wide anodont pectinate chaetae with 3–4 thick internal teeth (type 4) or 10 long teeth (type 3).

Further from the Australian coast, M. baudini n. sp. is similar to Marphysa victori Lavesque, Daffe, Bonifácio & Hutchings, 2017 (synonym of Marphysa bulla Liu, Hutchings & Kupriyanova, 2018 ) with the presence of ventral cirri with inflated bases and thick, wide anodont pectinate chaetae. However, M. baudini n. sp. has four types of pectinate chaetae instead of three present for M. victori , branchiae with four filaments maximum instead of six for M. victori and pygidium with two pairs of cirri while M. victori has only a single pair. Marphysa baudini n. sp. has subacicular hooks starting from anterior body (about chaetiger 40), while these hooks are absent in large specimens and present on the posterior part (from chaetiger 60) of small specimens (length 30 mm) only for M. victori ( Lavesque et al. 2020) .

In conclusion, to the best of our knowledge, similar thick wide pectinate chaetae with few coarse teeth have only been reported for specimens misidentified as M. sanguinea from Northeast and Northwest Pacific Coast (Hartman 1944; Imajima 2007). These specimens share with M. baudini n. sp. shape of prostomium, prostomial appendages, peristomium, dorsal cirri, branchial filaments, parapodial features and chaetae, as well as distribution of branchiae. However, they differ in the distribution of subacicular hook, in the maximum number of branchial filaments and in the lack of anterior thin narrow pectinate chaetae.