Marphysa sanguinea ( Montagu 1813 )

Molina-Acevedo, Isabel C. & Idris, Izwandy, 2020, Reinstatement of species belonging Marphysa sanguinea complex (Annelida Eunicidae) and description of new species from the mid-Pacific Ocean and the Adriatic Sea, Zootaxa 4816 (1), pp. 1-48 : 24-28

Marphysa sanguinea ( Montagu 1813)

Figures 8 , 9H , Table 1

Nereis sanguinea Montagu, 1813: 20–21 , Plate 3, Figs. 1–3 .

Leodice opalina . —Savigny in Lamarck, 1818: 323.

Nereidonta sanguinea . — de Blainville 1828a: 477.

Eunice sanguinea . —Audouin & Milne-Edwards 1834: 147–148 (partim).— Grube 1878: 51–52. Marphysa sanguinea . — de Quatrefages 1866: 332–333.— Baird 1869: 352.— McIntosh 1910: 442–448.— Fauvel,1923: 408– 410, Fig. 161.—Hutchings & Karageorpolous 2003: 88–90, Figs. 1 A–F, 2A, C, 4A, C.— Wijnhoven & Dekker 2010: 431–435, Figs. 2 , Table 1 –2.— Hutchings, Glasby & Wijnhoven 2012: 278–281, Fig. 2–3 .— Lavesque et al. 2019: 4–10, Fig.1–3 .— Martin et al. 2020: 27–28 (Distribution range).

Material examined. Type material: Neotype BNHM 1867.1 .7.24, Polperro , Cornwall, in mud and gravel at low water mark, coll. R. Laughrin, P. Hutchings (two specimens from this lot), Desig. P. Hutchings, 5019.6667’N 430.75’W . Additional material: LACM-AHF-P0000, Mount Edgecombe Plymouth, UK, 5021.1667’ N 049.5 ’W, 25 Oct 1999 – 28 Sep 2000, in burrows in rock crevices, low intertidal, coll. P. Karageorgopoulos. BNHM 1 ex 1867.1.24, 2002.844-845, NHM 2 ex 1867.1.24, Polperro, Cornwall, 2002, in mud and gravel at low water mark, coll. R. Laughrin, P. Hutchings .

Description. Neotype complete, gravid female, with 286 chaetigers, L10= 16.7 mm, W10= 10 mm TL= 300 mm, last four chaetigers regenerating. Anterior region of the body with dorsum convex and flat ventrum; body depressed from chaetiger 12, widest at chaetiger 33, tapering after chaetiger 99.

Prostomium bilobed, 5 mm long, 3.2 mm wide; lobes frontally rounded; median sulcus shallow anteriorly and deep ventrally ( Fig. 8 A–B). Prostomial appendages in a semicircle, median antenna isolated by a gap. Palps reaching second peristomial ring; lateral antennae reaching first chaetiger; median antenna broken, reaching first chaetiger, (in BNHM ex 1867.1.24. reaching middle of first chaetiger). Palpophores and ceratophores ring-shaped, short, thick; palpostyles and ceratostyles tapering, slender. Eyes oval, brown, between palps, and lateral antennae.

Peristomium (4 mm long, 9.5 mm wide) wider than prostomium, first ring two times longer than second ring, separation between rings distinct only dorsal and ventrally ( Fig. 8 A–C). Ventral lip dissected, in BNHM ex 1867.1.24 with a slight central anterior depression and several shallow wrinkles ( Fig. 8B ).

Maxillary apparatus with MF= 1 + 1, 4 + 4, 5 + 0, 3 + 6, 1 + 1 ( Fig. 8D ). MI 2.9 times longer than length of maxillary carriers. MI forceps-like, MI 4 times longer than length of closing system ( Fig. 8 D–E); ligament between MI and MII, sclerotized. MII wide, with recurved triangular teeth; MII 3.7 times longer than length of cavity opening ( Fig. 8 D–E); ligament between MII and MIII and right MIV, slightly sclerotized. MIII with triangular teeth; with irregular attachment lamella, situated in center of right edge of the plate, slightly sclerotized ( Fig. 8 D–E). Left MIV with two lateral teeth larger than rest; attachment lamella semicircle, slender, better developed in right side, situated 2/3 along of anterior edge of maxilla. Right MIV with three lateral teeth larger than rest; attachment lamella semicircle, wide, better developed in central side, situated 2/3 along anterior edge of maxilla, sclerotized ( Fig. 8 D–E). MV square, with a short triangular tooth. Mandibles lost, in BNHM ex 1867.1.24 dark;; calcareous cutting plates presents, sclerotized cutting plates brown, with 17 growth rings ( Fig. 8F ) .

Pectinate branchiae with up to five long filaments, present from chaetigers 23L–25R to 273L–277R (Fig. 38J). First three chaetigers with one filament; reaching the maximum five in chaetigers 75L–152L ( Fig. 9H ). Branchial filaments longer than dorsal cirri except in first four branchiae.

First three parapodia smaller, best developed in chaetigers 5–65, following ones becoming gradually smaller. Dorsal cirri conical in all chaetiger; longer than central cirri in anterior and posterior chaetigers, shorter in median chaetigers; best developed in chaetigers 4–33, following ones gradually smaller ( Fig. 8 G–K). Prechaetal lobes short, as transverse folds in all chaetigers ( Fig. 8 G–K). Chaetal lobes rounded in first 48 chaetigers, shorter than postchaetal lobe, aciculae emerging dorsal to midline; triangular from chaetiger 49, longer than other lobes, acicula emerging in midline ( Fig. 8 G–K). Postchaetal lobes well developed in first 50 chaetigers; digitiform in first four chaetigers, ovoid in chaetigers 5–9, rounded from chaetiger 10; progressively smaller from chaetiger 22; from chaetiger 51 inconspicuous ( Fig. 8 G–K). Ventral cirri digitiform in first four chaetigers; in chaetiger five to 252 with a short oval swollen base and digitiform tip; conical from chaetiger 253, gradually reducing in size ( Fig. 8 G–K).

Aciculae blunt, reddish basally amber distally ( Fig. 8 G–K). First chaetiger with three aciculae; in chaetigers 2–4 with four aciculae; in chaetigers 5–15 with five aciculae; in chaetigers 16–21 with six aciculae; in chaetigers 22–38 with eight aciculae; in chaetigers 39–51 with six aciculae; in chaetigers 52–77 with five aciculae; in chaetigers 78–100 with four aciculae; in chaetigers 101–128 with four or three aciculae; from chaetigers 165 with two aciculae.

Limbate chaetae of two lengths in same chaetiger; long and short, long blades in dorsal position, short blades in ventral position; limbate chaetae reduced in number around chaetiger 29, and then maintained a similar number until the posterior end. Three types of pectinate chaetae; in anterior chaetigers, thin, isodont narrow, asymmetric, with long and slender teeth, with 1–2 pectinate, up to 10 teeth ( Fig. 8L ); in median-posterior chaetigers, thick, isodont wide, asymmetric, with short and slender teeth, 18–20 chaetae with up to 18 teeth ( Fig. 8M ); in posterior chaetigers, thick, anodont wide, symmetric, with long and slender teeth, 4–5 chaetae with up to 10–12 teeth ( Fig. 8N ). Compound spinigers present throughout, with blades of two lengths in the same chaetiger: shorter blades slightly more abundant than longer blades ( Fig. 8O ). Subacicular hooks unidentate, reddish basally translucent distally; starting from chaetiger 109, one per chaetiger, present discontinuously after chaetigers 109 ( Fig. 8P ). In LACM-AHF 0000 subacicular hook bidentate, amber at the base, translucent distally; with blunt teeth, of similar size, distal teeth directed upward, proximal directed laterally.

Pygidium with dorsal pair of anal cirri as long as last five chaetigers; ventral pair short, as long as last chaetiger.

Variation. Material examined with L10 = 11.5–20.4 mm, W10 = 7.2–11 mm, TChae = 239–320. Palps reaching middle of first or second peristomial ring; lateral antennae reaching second peristomial ring or first chaetiger; median antenna reaching middle second peristomial ring or second chaetiger. The maxillary formula is variable: MII 4 + 4–5, MIII 5–6, MIV 3–4 + 6–8. The proportions of the maxillary apparatus vary as follows: MI are 2.9–3.2 times longer than length of maxillary carriers; MI are 3.8–5.6 times longer than length of closing system varies; MII are 3.7–4.4 times longer than length of cavity opening. Branchiae from chaetigers 21–25 to 9–18 chaetigers before pygidium. Maximum number of branchial filaments varied from five to six and postchaetal lobes were conspicuous in first 50–70 chaetigers. Ventral cirri with a swollen base from chaetigers 5–8 to 8–18 chaetigers before of pygidium. Start of subacicular hooks in chaetigers 74–286. In LACM-AHF 0000 the subacicular hook bidentate, amber at the base, translucent distally.

Distribution. Northeast Atlantic states (south England, France, and Netherland). See Martin et al. (2020) for more information.

Habitat. According to Hutchings & Karageorgopoulos (2003) the specimens live in a deep burrows, in crevices inside the rocks at low watermark.

Remarks. The species was recently characterized by Lavesque et al. (2019), and this authors disclosed its COI sequences from material from the type locality. Herein, based on the neotype, the descriptions of the maxillary apparatus, the branchiae, parapodia, simple and compound chaetae were expanded. The materials studied in Lavesque et al. (2019) presented a swollen triangular postchaetal lobe in anterior region; however, we find more than a single shape in the neotype. In the first four chaetigers the postchaetal is digitiform, from chaetigers 5–9 it is ovoid, and that from chaetiger 10 it is rounded and reduced in size. Possibly the triangular swollen shape matches the ovoid shape found in the neotype. Furthermore, Lavesque et al. (2019) described the specimens with subacicular hook bidentate; however we found unidentate subacicular hooks in the neotype. This pattern, where the two types of hooks are present, was already found in M. acicularum ( Molina-Acevedo & Carrera-Parra 2015) and herein in M. baileybrockae n. sp.. The presence of unidentate hook was explained probably due to wear on the proximal tooth. Likewise, smallest organism in Paucibranchia disjuncta ( Hartman, 1961) presented bidentate hooks, but in the larger ones the hook was unidentate ( Molina-Acevedo 2018).

Figures

FIGURE 1. Marphysa americana. Holotype BNHM 1932.12.24.554-556. A. Anterior end, dorsal view; B. Anterior end, ventral view; C. Anterior view, lateral view; D. Maxillary apparatus, dorsal view; E. Left MI-II-III-IV-V, lateral view; F. Mandible; G. Parapodium 3; H. Parapodium 6; I. Parapodium 12; J. Parapodium 247; K. Parapodium 377; L. Compound spinigers, chaetiger 6; M. Thin, isodont narrow, asymmetric, with long and slender teeth, chaetiger 6; N. Thick, isodont wide, symmetric, with short and slender teeth, chaetiger 325; O. Thick, isodont wide, asymmetric, with long and thick teeth, chaetiger 325; P. Thick, anodont wide, asymmetric, with long and thick teeth, chaetiger 377; Q. Subacicular hook, chaetiger 367.All chaetigers in anterior view; al-MIII: attachment lamella MIII; al-MIV: attachment lamella MIV. Scale bars: A–C, 3 mm; D, 1.4 mm; E. 0.9 mm; F. 1.3 mm; G–K, 0.2 mm; L, 0.1 mm; M–Q, 30 µm.

FIGURE 2. Marphysa baileybrockae n. sp. A. Anterior end, dorsal view; B. Anterior end, ventral view; C. Anterior end, lateral view; D. Maxillary apparatus, dorsal view; E. Left MI-II-III-IV-V, lateral view; F. Mandible; G. Parapodium 3; H. Parapodium 8; I. Parapodium 16; J. Parapodium 250; K. Parapodium 308; L. Thin, isodont narrow, symmetric, with short and slender teeth, chaetiger 8; M. Thick, anodont wide, symmetric, with long and thick teeth, chaetiger 295; N. Thick, isodont wide, symmetric, with long and slender teeth, chaetiger 358; O. Compound spinigers, chaetiger 8; P. Subacicular hook unidentate, chaetiger 122; Q. Subacicular hook bidentate, chaetiger 152. A–O from holotype USNM 5444, P–Q from paratype AMNH 367. All chaetigers in anterior view; al-MIII: attachment lamella MIII; al-MIV: attachment lamella MIV. Scale bars: A–C, 2.9 mm; D–E, 1 mm; F, 0.8 mm; G–K, 0.1 mm; L–Q, 30 µm.

FIGURE 3. Marphysa birgeri n. sp. A. Anterior end, dorsal view; B. Anterior end, ventral view; C. Anterior end, lateral view; D. Maxillary apparatus, dorsal view; E. Mandible; F. Parapodium 3; G. Parapodium 7; H. Parapodium 14; I. Parapodium 67; J. Parapodium 103; K. Thin, isodont narrow, symmetric, with long and slender teeth, chaetiger 14; L. Thin, isodont wide, asymmetric, with short and slender teeth, chaetiger 85; M. Thick, anodont wide, symmetric, with long and slender teeth, chaetiger 85; N. Thick, anodont wide, asymmetric, with long and thick teeth, chaetiger 105; O. Compound spinigers, chaetiger 7; P. Subacicular hook, chaetiger 85. A–O from holotype F.2021, P from paratype 12273. All chaetigers in anterior view; al-MIII: attachment lamella MIII; al-MIV: attachment lamella MIV. Scale bars: A–C, 1.4 mm; D–E, 0.5 mm; F–J, 0.2 mm; K–N, 30 µm; O–P, 0.1 mm.

FIGURE 8. Marphysa sanguinea (Montagu, 1813).A.Anterior end, dorsal view; B.Anterior end, ventral view; C.Anterior end, ventro-lateral view; D. Maxillary apparatus, dorsal view; E. Left MI-II-III-IV-V, lateral view; F. Mandible; G. Parapodium 3; H. Parapodium 5; I. Parapodium 12; J. Parapodium 174; K. Parapodium 275; L. Thin, isodont narrow, asymmetric, with long and slender teeth, chaetiger 30; M. Thick, isodont wide, asymmetric, with short and slender teeth, chaetiger 174; N. Thick, anodont wide, symmetric, with long and slender teeth, chaetiger 275; O. Compound spiniger, chaetiger 193; P. Subacicular hook, chaetiger 193. A–E, G–P from BNHM 1867.1.7.24; F from BNHM 1 ex 1867.1.24, 2002.844-845. All chaetigers in anterior view; al-MIII: attachment lamella MIII; al-MIV: attachment lamella MIV. Scale bars: A–C, 4.2 mm; D–E, 1.8 mm; F, 1.2 mm; G–K, 0.2 mm; L–O, 30 µm; P, 0.1 mm.

FIGURE 9. Distribution of branchial filaments throughout the body in A. Marphysa americana Monro, 1933 n. status.; B. Marphysa baileybrockae n. sp.; C. Marphysa birgeri n. sp.; D. Marphysa brevibranchiata Treadwell, 1921 n. status.; E. Marphysa californica (Moore, 1909); F. Marphysa leidii de Quatrefages, 1866; G. Marphysa parishii Baird, 1869; H. Marphysa sanguinea (Montagu, 1813).