Lanice conchilega ( Pallas, 1766 )

Lavesque, Nicolas, Daffe, Guillemine, Londoño-Mesa, Mario H. & Hutchings, Pat, 2021, Revision of the French Terebellidae sensu stricto (Annelida, Terebelliformia), with descriptions of nine new species, Zootaxa 5038 (1), pp. 1-63 : 28-31

Lanice conchilega ( Pallas, 1766)

Figures 12–13

Nereis conchilega Pallas, 1766: 131–138 , pl. 9, figs 14–22.

Lanice conchilega .— Saint-Joseph 1894: 211–218, pl. IX, figs 241–245; Fauvel 1927: 255–257, fig. 88; Holthe 1986: 120–122, fig. 53.

Other synonyms. Amphitrite flexuosa Delle Chiaje, 1828 ; Amphitrite tondi Delle Chiaje, 1828 ; Terebella artifex Sars, 1863 ; Terebella flexuosa Delle Chiaje, 1828 ; Terebella littoralis Dalyell, 1853 ; Terebella pectoralis Quatrefages, 1866 ; Terebella prudens Quatrefages, 1866 ; Wartelia gonotheca Giard, 1878 .

Material examined. MNHN-IA-PNT 129, posteriorly incomplete, English Channel , Luc-sur-Mer, 49°19’10”N 0°20’57”W, intertidal, July 2016 . MNHN-IA-PNT 130, posteriorly incomplete, English Channel , Chausey Islands, 48°54’29”N 1°46’54”W, depth 15 m, March 2016 , posterior part used for molecular analysis. SMA-Din- Lan-02, posteriorly incomplete, English Channel , Chausey Islands, 48°54’29”N 1°46’54”W, depth 15 m, March 2016 , posterior part used for molecular analysis. SMA-Din-Lan-03, incomplete, English Channel , Chausey Islands, 48°54’29”N 1°46’54”W, depth 15 m, March 2016 .

Comparative material. SMA-NEW-01, posteriorly incomplete, North Sea , Belgium, Nieuwpoort, 51°09’13”N 2°43’18”E, intertidal, August 2019, posterior part used for molecular analysis. SMA-NEW-02, posteriorly incomplete, North Sea, Belgium, Nieuwpoort, 51°09’13”N 2°43’18”E, intertidal, August 2019, posterior part used for molecular analysis .

Description. Relatively small species with the longest incomplete specimen studied being 42.3 mm long and 1.7 mm wide, for 25 segments.

Prostomium at base of upper lip, without eyespots, distal part forming a shelf-like tentacular membrane from which numerous filiform, wrinkled and deeply grooved buccal tentacles originate ( Fig. 12D ). Peristomium well developed with conspicuous hood-like convoluted upper lip, dorsally with brown pigment, and short and swollen lower lip, partially covered by lobes of SG I ( Figs 12B–D ; 13A ).

Segment I with pair of large lobes directed anteriorly and reaching distal part of upper lip; lobes almost oval, pointed anteriorly, with thin margin; continuing across dorsum as narrow crest, connected mid-ventrally by thin convoluted membrane, mid-ventrally indented to partially expose lower lip ( Fig. 12A–C ). Segment II short without lateral lobes and laterally covered by lobes of SG III, visible ventrally with a pointed anterior projection; absence of glandular membrane connecting first pair of branchiae. Segment III with pair of large, auricular lobes, reaching mid-length of lobes of SG I laterally; ventral edges fused laterally to first mid-ventral shield. Absence of lateral lobes on SG IV ( Figs 12A–C ; 13A–B ).

Three pairs of arborescent branchiae on SG II–IV, dorsally aligned, with short branchial filaments, with short basal stems ( Figs 12A ; 13A–B ). Rectangular corrugated mid-ventral shields on SG II–SGXV (XVI), fused on SG II–IV, followed by 3–4 smaller trapezoidal shields from SG XVI (XVII) ( Fig. 12B–C ).

Notopodia beginning on SG IV, extending until SG XX; notopodia short, globular, almost inconspicuous on several specimens ( Figs 12A ; 13A–C ). Narrowly-winged notochaetae in two rows ( Fig. 12E ), with first row shorter.

Neuropodia present from SG V, as low sessile ridges until end of notopodia ( Figs 12A–C ; 13A–D ), short and reaching mid-ventral shields; as elongate and thin, rectangular pinnules from SG XXI; inserted laterally to midventral groove on posterior segments. Neurochaetae throughout as short-handled avicular uncini, arranged in intercalated back-to-back double rows on SG XI–XX ( Fig. 13D ). Uncini with short triangular heel and rounded prow, with almost inconspicuous dorsal button inserted closer to prow than to base of main fang, convex base, main fang surmounted by crest with three rows of secondary teeth, first row with two large teeth, second row with one large and several irregularly-sized teeth, and third row with very small teeth ( Figs 12F–G ; 13D–F ).

Genital papillae on SG VI–IX, small, dorsally to notopodia ( Fig. 13A ).

Pygidium not seen.

Tube with sandy-branched projections on anterior margin.

Type locality. Holland, North Sea .

Type material. Probably lost or never designated ( Holthe 1986; Hutchings & Glasby 1988).

Distribution. Considered as a cosmopolitan species, present from Greenland to Antarctic ( Gil 2011), but probably restricted to Western Europe.

Habitat. Sandy beaches, intertidal to shallow waters (depth 15 m) (this study).

Remarks. Specimens sampled from the Belgian part of the North Sea, close to the type locality situated on the Dutch coast, are similar to the French specimens studied herein, both morphologically and molecularly ( Fig. 27 ). Moreover, these specimens match with the information provided by Hutchings & Glasby (1988), who examined specimens from the type locality (voucher USNM 44397). However, as for other species described during the 18 th century, the designation of a neotype, supported with molecular sequences, is desirable, as probably several different species may occur in Europe (see below).

Figures

FIGURE 12. Lanice conchilega (Pallas, 1766) SMA-Din-Lan-03 (A, C), SMA-Din-Lan-02 (B), MNHN-IA-PNT 129 (D), MNHN-IA-PNT 130 (E–F), SMA-New-Lan-02 (G). A. Anterior end, lateral view, MG staining; B. Anterior end, ventral view; C. Anterior end, ventral view, MG staining; D. Anterior end, dorsal view; E. Notochaetae, SG X; F–G. Uncini, SG X.Abbreviations: Bt, buccal tentacles; Ll, lower lip; ne, neuropodia; Ul, upper lip. Numbers referring to segments.

FIGURE 13. Lanice conchilega (Pallas, 1766) SEM SMA-Din-Lan-03, SEM. A–B. Anterior end, lateral view; C. Thoracic part, lateral view; D. Thoracic uncini in double row; E. Uncini, SG V; F. Abdominal uncini. Abbreviations: ne, neuropodia; NP, nephridial papillae; Ul, upper lip. Numbers referring to segments.

FIGURE 27. Majority-rule consensus tree from Bayesian analysis using 16S. Asterisk indicates posterior probability> 80%. Text in red refers to specimens sequenced during this study.