Terebellides bonifi, Lavesque & Hutchings & Daffe & Nygren & Londoño-Mesa, 2019

Lavesque, Nicolas, Hutchings, Pat, Daffe, Gullemine, Nygren, Arne & Londoño-Mesa, Mario H., 2019, A revision of the French Trichobranchidae (Polychaeta), with descriptions of nine new species, Zootaxa 4664 (2), pp. 151-190 : 157-160

Terebellides bonifi n. sp.

Figures 3–4 , Table 2

Type material: Holotype: MNHN-IA-TYPE 1859, gravid, incomplete, Mediterranean Sea , Gulf of Lion, A90, 42°32’39”N, 3°16’03”E, 90 m depth, April 2018 . Paratypes: MNHN-IA-TYPE 1860, one specimen, complete (posterior part used for molecular analysis), Mediterranean Sea , Gulf of Lion , A90, 42°32’39”N, 3°16’03”E, 90 m depth, April 2018 ; MNHN-IA-TYPE 1861, one specimen, complete, Mediterranean Sea , Gulf of Lion , A90, 42°32’39”N, 3°16’03”E, 90 m depth, April 2018 . MNHN-IA-TYPE 1862, one specimen, gravid, complete, Mediterranean Sea, Gulf of Lion, A90, 42°32’39”N, 3°16’03”E, 90 m depth, April 2018, mounted for SEM. All type specimens fixed with 96% alcohol .

Description. Relatively large species, with incomplete holotype 29.8 mm long (22.2– 24.3) and 1.8 mm (1.8–2 mm). Body tapering posteriorly with segments becoming increasingly shorter and more compacted towards pygidium.

Prostomium compact; eyespots absent; large upper lip surrounding mouth with many buccal tentacles ( Fig. 3 B–D). Buccal tentacles of 2 types, uniformly cylindrical and with expanded tips, spatulate ( Fig. 3 C–D). Lower lip forming an expanded structure below upper lip ( Fig. 2B, D ). SG 1 and 2 short, only visible ventrally; following segments with lobes as ventral collars ( Fig. 2B ). Lateral lappets on SG 3–6 ( TC 1–4), continuing ventrally in TC 1–5, largest on TC 1 and declining in size posteriorly ( Figs 3B, D & 4A ). Conspicuous dorsal rounded projection on TC 1–3 ( Figs 3B, D & 4A ). Presence of oval glandular lateral region on TC 3 ( Fig. 3D ).

Branchiae arising as a single structure from TC 1, reaching TC 4 ( TC 3), consisting of single elongate and annulated stalk placed mid-dorsally ( Figs 3 A–D & 4A), 2 pairs of lobes, fused for about 1/2 of length, lower pair thinner. Upper lobes with about 45 tightly packed lamellae ( Figs 3 A–D & 4A–B). Anterior lamellae of each branchia with short conical papillae, visible under stereomicroscope ( Figs 3C & 4 A–B). Distal region of upper lobes with short projections, lower lobes with long projections ( Fig. 3 C–D). Anterior branchial projection (5 th lobe) present ( Figs 3 A–B, D & 4A).

Eighteen pairs of thoracic notopodia ( SG 3–20). First notopodium slightly longer than subsequent notopodia; notochaetae from TC 1 about same size as ones from subsequent notopodia, and transversally aligned ( Fig. 3D ). All notochaetae simple capillaries, arranged in two rows. Neuropodia present as sessile pinnules from TC 6 ( SG 8) to pygidium; uncini arranged in single rows from TC 7. First thoracic neuropodium ( TC 6) provided with 5–7 sharply bent acute tipped, geniculate chaetae. All subsequent thoracic neuropodia with about 12–15 uncini per torus arranged in one irregular row. Uncini as shafted denticulate hooks provided with long, thin and pointed main fang. Three or four teeth above the main fang, surmounted by a row of three to five short denticles and an upper crest of several minute denticles ( Fig. 4C ). About 32 abdominal neuropodia as erect pinnules, paddle-shaped with entire margin provided with about 40 uncini; uncini with four pointed teeth above main fang, surmounted by a row of three short pointed teeth and an upper crest of minute teeth ( Fig. 4D ).

Two pairs of globular nephridial papillae, located latero-posteriorly to base of each notopodium of TC 4 and TC 5. Pygidium crenulated, as a funnel-like depression.

Methyl green staining pattern. First 4 TC stain solid; TC 5 and TC 11 with distinct stripes; ventral faces of lobes stained dark blue; glandular region blue ( Fig. 3 C–D).

Etymology. The species is named after Paulo Bonifácio, alias Bonif, for his friendship and for being an excellent and fascinating worms’ teacher to NL.

Habitat. Mud, about 90 m depth.

Type locality. Western Mediterranean Sea (Gulf of Lion), France ( Fig. 1 ) .

Distribution. Only known from type locality.

Remarks. Terebellides bonifi n. sp. is characterized by the papillar projections pointing over the edge of the branchial lamellae. By this characteristic, T. bonifi n. sp. is similar to T. europea n. sp., T. gentili n. sp., T. lilasae n. sp., T. resomari n. sp. and T. stroemii from Adriatic Sea ( Parapar et al. 2013) (see T. lilasae n. sp. remarks). Among these species, T. bonifi n. sp. is similar to T. europea n. sp., in having papillar projections on anterior lamellae only, but differs from this species by the presence of an oval glandular region on TC 3 (instead of undulating one for T. europea n. sp.) and presence of rounded conspicuous dorsal projection on TC 1–3. The presence of oval glandular region T. bonifi n. sp. is similar of that present in T. lilasae n. sp. and T. stroemii from Adriatic. However, these species differ by the absence of papillar projections on posterior branchial lamellae in T. bonifi n. sp. (presence on most of the lamellae T. lilasae n. sp. and T. stroemii from Adriatic), and by the shape of papillar projections, conical for T. bonifi n. sp., and rounded for T. lilasae n. sp. and T. stroemii from Adriatic.

Molecular results, based on material available for this study, show that T. bonifi n. sp. appears to be absent from Northern waters ( Fig. 23 ).

Figures

FIGURE 1. Schematic distribution of the different Trichobranchidae species along the French coasts. Text in italic represents type locality of new species. Abbreviation: WGMP, West Gironde Mud Patch.

FIGURE 2. Octobranchus lingulatus (Grube, 1863) SEM, MNHN-IA-PNT 94A. Entire worm, lateral view B. Anterior region, lateral view; C. Anterior region, dorsal view; D. Buccal tentacles; E. Uncini, thoracic chaetiger; F. Uncini, abdominal chaetiger. Scales: A=500 µm, B=250 µm, C=125 µm, D=50 µm, E–F=10 µm.

FIGURE 3. Terebellides bonifi n. sp. paratype MNHN-IA-TYPE 1861 (A), paratype MNHN-IA-TYPE 1860 (B), holotype MNHN-IA-TYPE 1859 (C–D) A. Entire worm, lateral view; B. Anterior part, lateral view; C. Anterior part, dorsal view, methyl green staining; D. Anterior part, lateral view, methyl green staining. Abbreviation: glr, glandular lateral region. Arrow indicate conspicuous dorsal rounded projection of TC1. Scales: A=2 mm, B=1 mm, C–D=0.5 mm.

FIGURE 4. Terebellides bonifi n. sp. SEM paratype MNHN-IA-TYPE 1862 A. Anterior part, lateral view; B. Papillar projections on edge of anterior branchial lamellae, lateral view; C. Uncini, thoracic chaetiger; D. Uncini, abdominal chaetiger. Arrow indicate conspicuous dorsal rounded projection of TC1. Scales: A=500 µm, B=200µm, C=15 µm, D=15 µm.

FIGURE 23. Maximum likelihood trees of valid European Terebellides species and available sequences of Terebellides species obtained in this study, based on A. 16S sequences; B. COI sequences. Values on nodes represent posterior probabilities> 0.5 (first values), or Maximum likelihood bootstrap support> 50 (second values). Sequence accession numbers refer to Table 1 and Nygren et al. (2018), text in red to specimens sequenced during this study.