Terebellides talboti, Lavesque & Hutchings, 2025

Terebellides talboti sp. nov.

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Figures 8 View FIGURE 8 and 9 View FIGURE 9

Material examined. Holotype. SAMC-A065087 , South East Atlantic , South Africa, Western Cape, Lamberts Bay , 32.075°S, 18.233°E, September 1971, entire GoogleMaps . Paratypes. Three paratypes from the same collection site as the holotype, SAMC-A097161 , two mounted for SEM GoogleMaps .

Description. Large-size species, holotype 51.9 mm long and 4.6 mm wide. Body tapering posteriorly, segments increasingly shorter and more compacted towards pygidium. Preserved specimens whitish.

Prostomium compact; eyespots absent; large upper lip surrounding mouth; buccal tentacles of two types, uniformly cylindrical and with expanded tips, spatulate ( Fig. 8 View FIGURE 8 ). Lower lip expanded below upper lip ( Figs 8C View FIGURE 8 ; 9A View FIGURE 9 ). SGs I and II only visible ventrally; following segments with lobes as ventral collars, lateral lappets on SG IV–IX (TC 2–7) continuing ventrally; absence of dorsal rounded projections on anterior segments; absence of glandular lateral region on SG V (TC 3) ( Figs 8A, C–D View FIGURE 8 ; 9A View FIGURE 9 ).

Branchiae arising as a single structure from SG III, reaching SG X, as single elongate and annulated mid-dorsal stalk, with two pairs of lobes, fused for approximately 1/2 of length, lower pair thinner; anterior branchial projection (5 th lobe) present. Dorsal lobes with about 70 separated lamellae; papillar projections on margins and ciliated tufts present; dorsal and ventral lobes terminating with pointed projections ( Figs 8 View FIGURE 8 ; 9A–C View FIGURE 9 ).

Eighteen pairs of thoracic notopodia (SG III–XX), first pair reduced, notochaetae from TC 1 (SG III) about same size as those from subsequent notopodia. All notochaetae simple capillaries, arranged in two rows, anterior row shorter. Neuropodia as sessile pinnules from TC 6 (SG VIII) to pygidium. First thoracic pair of neuropodia (TC 6) with 7–11 sharply bent geniculate chaetae, with acute tips ( Fig. 9D View FIGURE 9 ), subsequent thoracic neuropodia (from TC 7) with about 15–20 uncini per torus arranged in irregular row, rostrum vs. capitium length ratio RvC =1/0.3, four mid-sized teeth above main fang surmounted by three rows of short denticles and upper crest of several minute denticles ( Fig. 9E View FIGURE 9 ); about 30–35 pairs of abdominal neuropodia, as erect paddle-shaped pinnules, each with about 25 uncini present at margin; RvC=1/0.9, 5–6 teeth above main fang, surmounted by row of 4–5 short teeth and two rows of shorter denticles ( Fig. 9F View FIGURE 9 ).

Two pairs of large nephridial papillae posterior to base of notopodia of SG VI–VII (TC 4–TC 5) ( Fig. 8D View FIGURE 8 ). Pygidium rounded.

Methyl Green staining pattern: the first 7–8 segments stain solid; striped from SG VIII–IX to SG XIII–XIV, lateral thin stripe until end of the body; ventral faces of branchial lobes stain dark blue ( Fig. 8 View FIGURE 8 ).

Etymology. This species is dedicated to Frank Talbot, a renowned marine biologist and former Director of the Australian Museum, the California Academy of Sciences and the Smithsonian Natural History Museum. Frank Talbot, who was Pat Hutchings’ friend, was born in South Africa and received his PhD from the University of Cape Town. He died in 2024, aged 94 years old.

Habitat. Coastal.

Type locality. South Africa, Western Cape, Lamberts Bay .

Distribution. Known from type locality only.

Remarks. Before this study, only two species were reported from this part of Africa: T. augeneri and Terebellides sp. 2 ( Parapar et al. 2020a). Terebellides talboti sp. nov. differs from T. augeneri by the presence of a fifth branchial lobe which is absent for T. augeneri and by the fusion of branchial lobes at least on 50 % of their length while these lobes are free for T. augeneri . The two species differ by the presence of branchial papillae on the margins of branchial lamellae for Terebellides talboti sp. nov., these papillae are absent for T. augeneri . An undescribed species ( Terebellides sp. 2 ) has been reported by Parapar et al. (2020a) from Cape Point. Even if this specimen was in poor condition, this species is characterised by the presence of white ventral colouration on the first five chaetigers, which is not the case for Terebellides talboti sp. nov.

Terebellides talboti sp. nov. differs from Terebellides simonae sp. nov. by the absence of dorsal rounded projection on the first three chaetigers and absence of a glandular lateral region, which are both present for Terebellides simonae sp. nov. Terebellides talboti sp. nov. differs also by the presence of free branchial lobes which are fused for 50% of their length for Terebellides simonae sp. nov. Finally, the branchial lobes of Terebellides talboti sp. nov. have pointed projections while those of T. simonae sp. nov. have filamentous tips.

Among the other West African species of Terebellides , and with the absence of a glandular lateral region and the presence of a fifth branchial lobe, T. talboti sp. nov. is similar to T. fauveli Parapar, Martin & Moreira, 2020 , T. longisetus Parapar, Martin & Moreira, 2020 and Terebellides sp. 1 ( Parapar et al. 2020a). Terebellides talboti sp. nov. differs from these three species by the presence of branchial lobes which are fused for 50% of their length instead of free ones for the other species, and by the presence of papillae on the margins of branchial lamellae which are absent for the other three species. Terebellides fauveli and T. longisetus have branchial lobes with filamentous tips while T. talboti sp. nov. ones have pointed projections and finally Terebellides sp. 1 is characterized by the greater development of its tentacular membrane which is not the case for T. talboti sp. nov.