Eupolymnia lacazei, Lavesque & Daffe & Londoño-Mesa & Hutchings, 2021

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 : 22-24

Eupolymnia lacazei n. sp.

Figures 8–9

Material examined. Holotype. MNHN-IA-TYPE 2022, posteriorly incomplete, Mediterranean Sea , Gulf of Lion, Reserve St Troc, 42°28’52”N 3°08’38”E, depth 15 m, December 2020 . Paratypes. AM W.53326, posteriorly incomplete, Mediterranean Sea , Gulf of Lion , Reserve St Troc , 42°28’52”N 3°08’38”E, depth 15 m, December 2020, few parapodia used for molecular analysis. MNHN-IA-TYPE 2023, posteriorly incomplete, Mediterranean Sea , Gulf of Lion, Reserve St Troc, 42°28’52”N 3°08’38”E, depth 15 m, December 2020, few parapodia used for molecular analysis, others mounted for SEM.

Additional material. SMA-COR-Tere-03, posteriorly incomplete, Mediterranean Sea , Corsica Cape, 42°47’12”N 9°19’48”E, depth 28 m, May 2019, few parapodia used for molecular analysis .

Description. In life, red body covered with white spots, buccal tentacles pinkish, stems and branches of branchiae red ( Fig. 8A ).

Small species, holotype incomplete, 29.8 mm long for about 55 segments (complete paratype 45.4 mm; 81 segments) and 1.8 mm wide (complete paratype 5.5 mm).

Transverse prostomium attached to dorsal surface of upper lip; basal part with continuous row of reddish eyespots ( Fig. 8C ) without mid-dorsal gap, with eyespots well separated from each other; distal part forming a shelflike tentacular membrane from which numerous thick and deeply grooved buccal tentacles originate ( Figs 8A ; 9A–B ). Peristomium forming lips; hood-like upper lip, rectangular, wider than long; lower lip thin, wider than high, with pharyngeal organ everted ( Fig. 8D ).

Arborescent branchiae present on SG II–IV, longitudinally aligned, dorsal to line of notopodia; with short and thick branchial filaments, branching dichotomously from long basal stem; first pair longer, following pairs progressively shorter ( Figs 8A–C ; 9B ).

Segment I well visible, ventrally developed, forming ventral lobe below lower lip ( Fig. 8D ); SG II with one pair of semi-circular ventro-lateral lobes, connected ventrally by a low crest, dorsal margins aligned with ventral edges of following neuropodia; SG III and IV with short semi-circular lateral lobes, about the same size, situated progressively more laterally, lobes of SG IV aligned with neuropodia of SG V ( Figs 8B–D ; 9A ).

Segments II–XVI with glandular, rectangular, smooth to slightly corrugated anteriorly mid-ventral shields, last three shields distinctly shorter; mid-ventral groove extending posteriorly from SG XVII ( Fig. 8D ).

Rectangular notopodia beginning from SG IV, extending for 17 segments, until SG XX, laterally aligned, notopodia of first two pairs shorter ( Fig. 8B ). Narrowly-winged notochaetae in two rows, first row shorter ( Fig. 8E ).

Neuropodia present from SG V, as low ridges until end of notopodia, as rectangular pinnules thereafter ( Fig. 8B–D ). Neurochaetae throughout as short-handled avicular uncini, arranged in completely intercalated double rows on SG XI–XX, in a face-to-face arrangement. Uncini with short triangular heel and rounded prow, with pointed dorsal button inserted closer to prow than to base of main fang, elongate convex base, and main fang surmounted by a crest with two rows of secondary teeth, first row with two large teeth and second row with several small teeth (middle tooth often larger) ( Figs 8F ; 9C–D ).

Nephridial papillae on SG III–V, posteriorly to bases of branchiae and dorsally to notopodia; genital papillae on SG VI–VIII, as round swellings between parapodial lobes, inserted posteriorly to notopodia.

Pygidium with about 12 papillae.

Etymology. This species is named after the French zoologist Henri de Lacaze-Duthiers (1821–1901), who founded the Laboratoire Arago in Banyuls-sur-Mer more than 100 years ago, and whose 200 th birthday is celebrated this year (2021). This species name was chosen by Céline Labrune from the Laboratoire Arago, who provided the type material.

Habitat. Under rocks, shallow waters (depth 15 m).

Type locality. Banyuls-Cerbere nature reserve , Catalan Sea, Western Mediterranean Sea, France, 42°28’52”N 3°08’38”E .

Distribution. Mediterranean Sea, Gulf of Lion and Corsica Cape.

Remarks. Among the European species, Eupolymnia lacazei n. sp. differs from E. meissnerae n. sp. by having eyespots arranged in a continuous band instead of the eyespots being separated by a mid-dorsal gap as for E. meissnerae n. sp., by the presence of long branchial stems which are short for the first pair of branchiae and absent for the second and third ones for E. meissnerae n. sp. Eupolymnia lacazei n. sp. differs also by the presence of semi-circular lateral lobes on SG II while E. meissnerae n. sp has auricular-shape lateral lobes and by uncini with two and one large tooth on the first and second rows above the main fang respectively, instead of two large teeth in the two first rows for E. meissnerae n. sp. Finally, E. lacazei n. sp. differs from E. meissnerae n. sp. by the colour pattern of live specimens. They have a red body covered with white spots for E. lacazei n. sp. and an orange pattern for E. meissnerae n. sp.

Eupolymnia lacazei n. sp., E. gili n. sp. and E. nebulosa belong to the same complex of “strawberry worms” due to their colourful pattern, with red body covered by white spots. However, E. lacazei n. sp. differs from E. gili n. sp. by the absence of thick and translucent lateral lobes on SG II–IV, by the absence of abdominal neuropodia with pointed dorsal projections and by the presence of ventral crest on SG II which is absent for E. gili n. sp.

Finally, E. lacazei n. sp. differs from E. nebulosa by the presence of long branchial stems which are absent for E. nebulosa , and by the presence of 15 ventral shields instead of 10 for E. nebulosa , by the shape of the lateral lobes of SG III, which are semi-circular for E. lacazei n. sp. and bilobed for E. nebulosa . The two species differ also by the shape of uncini. Their dorsal button are situated closer to the prow than to the base for E. gili n.sp. and at midway for E. nebulosa .

Eupolymnia lacazei n. sp. is relatively similar to two non valid species ( Read & Fauchald 2021): Amphitrite meckelii Delle Chiaje, 1828 and Pallonia rapax A. Costa, 1862 . Actually, these two species were described from the Gulf of Naples and have a red colour with white spots. However, the original description of A. meckelii states that “the cirri and gills are yellowish and branched, body pinkish with white almost pearly spots, feet with yellow bristles”. In contrast, E. lacazei n. sp. has a red body covered by white spots, buccal tentacles pinkish, stems and branchiae red. Morover, as mentioned by Jirkov (2020), A. meckelii should be considered as nomen dubium because this “original description does not provide enough information even to be sure about generic affiliation”. Concerning the original description of P. rapax, Costa says that “the following twenty rings (after the first ring) have on each side a small fleshy foot, in the form of an auricle, bearing a bundle of bristles” and “it lives in sandy bottoms in a tube consisting of grains of sand and crushed shells”. Even if P. rapax shares exactly the same colour pattern as E. lacazei n. sp., this species has 20 notopodia and thus should not belong to Eupolymnia . The two species occur in very different habitats, associated with sandy bottoms for P. rapax and under rocks for E. lacazei n. sp. In the absence of type material, Pallonia rapax should be considered as nomen dubium, as for A. meckelii it is not possible to be sure about its correct generic affiliation.

Figures

FIGURE 8. Eupolymnia lacazei n. sp. Paratype MNHN-IA-TYPE 2023 (A), holotype MNHN-IA-TYPE 2022 (B–F).A. Entire live specimen; B. Entire specimen, lateral view, MG staining; C. Anterior end, lateral view; D. Anterior end, ventral view, MG staining; E. Notochaetae, SG IX; F. Uncinus, SG IX. Abbreviations: Bt, buccal tentacles; Ll, lower lip; Po, pharyngeal organ; Ul, upper lip. Numbers referring to segments.

FIGURE 9. Eupolymnia lacazei n. sp. SEM paratype MNHN-IA-TYPE 2023. A. Anterior end, lateral view; B. Anterior end, dorso-lateral view; C. Uncini, SG XI; D. Uncini, SG VI. Numbers referring to segments.