Eupolymnia scholastica, Lavesque & Hutchings, 2025

Eupolymnia scholastica sp. nov.

zoobank.org:act: DB69D6F3-2645-416B-8500-4ED7D6681B34

Figures 2 View FIGURE 2 and 3 View FIGURE 3

Material examined. Holotype. SAMC-A089102 , South East Atlantic, South Africa, Western Cape, Kleinbaai , 34.617°S, 19.355°E, December 2011, posteriorly incomplete GoogleMaps . Paratypes. Two specimens, SAMC-A020434 , South East Atlantic, South Africa, Western Cape, South Agulhas , 34.841°S, 20.034°E, no date of collection, one mounted for SEM GoogleMaps .

Description. Large species with incomplete holotype (in three pieces) 39.8 mm long (35.8–45.8 mm) and 4.5 mm wide (4.7–6.2 mm), anterior part with 17 pairs of notopodia and three abdominal neuropodia.

Transverse prostomium attached to dorsal surface of upper lip; basal part with continuous row of black eyespots (absent on paratype SAM-MB-A020434), with a short mid-dorsal gap, with eyespots more or less separated from each other ( Fig. 2A View FIGURE 2 ); distal part forming a shelf-like tentacular membrane from which numerous filiform and grooved buccal tentacles originate ( Fig. 2A–D View FIGURE 2 ). Peristomium forming lips; hood-like upper lip, circular, wider than long, convoluted; lower lip thin, wider than long, pharyngeal organ everted ( Fig. 2B, D View FIGURE 2 ).

Arborescent branchiae present on SG II–IV, longitudinally aligned, dorsal to line of notopodia; with long branches and short branchial filaments branching dichotomously; first pair longer, following ones of similar size; with a short basal stem reducing from first to third pair of branchiae (almost absent for third pair of branchiae) ( Figs 2A, C–D View FIGURE 2 ; 3A View FIGURE 3 ).

Segment I conspicuous all around, ventrally developed, forming ventral lobe below lower lip ( Fig. 2B, D View FIGURE 2 ). Small lateral lobes present on SG II-IV, inserted progressively more dorsally and reducing in size. SG II with one pair of auricular-shaped ventro-lateral lobes, connected ventrally by a low crest, anterior margins undulating and glandular; SG III with auricular-shaped lateral lobes; SG IV with a pair of short rounded dorso-lateral lobes; dorsal margins of lateral lobes on SG IV aligned with dorsal margins of neuropodia ( Figs 2A, D View FIGURE 2 ; 3A–B View FIGURE 3 ). SG II–XVI with glandular, rectangular, smooth to slightly corrugated mid-ventral shields ( Fig. 2B, D View FIGURE 2 ); mid-ventral groove extending posteriorly from SG XVII ( Fig. 2B View FIGURE 2 ).

Rectangular notopodia beginning from SG IV, extending for 17 segments, until SG XX, laterally aligned ( Figs 2A View FIGURE 2 ; 3D View FIGURE 3 ). Narrowly-winged notochaetae in two rows ( Fig. 3D View FIGURE 3 ), first row shorter.

Neuropodia present from SG V, as low ridges until end of notopodia ( Fig. 3C View FIGURE 3 ), as rectangular pinnules thereafter. Thoracic neuropodia progressively more ventral. 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 rounded heel and with short pointed prow, pointed dorsal button inserted at about halfway distance between base of main fang and tip of prow, elongate convex base, and main fang surmounted by crests with two rows of secondary teeth and upper crest of several small denticles, first row with two large teeth, second row with one large median tooth and two small lateral ones ( Figs 2E View FIGURE 2 ; 3E–F View FIGURE 3 ).

Nephridial papillae on SG III–V, posteriorly to bases of branchiae and dorsally to notopodia; genital papillae on SG VI–VIII, globular, inserted posteriorly to neuropodia.

Pygidium unknown.

Methyl Green staining pattern: Anterior parts of ventral pads, lateral lobes, glandular areas around notopodium and neuropodium stained in blue ( Fig. 2B, D View FIGURE 2 ).

Etymology. The name of this new species was chosen during an educational project on biodiversity and marine worms with CM2 pupils (10 years old) from the Gambetta school (Gujan-Mestras, France). This species name come from the Latin word “scholasticus” (=schools, scholars) and refers both to these children's school and to the importance of schooling for all children in the world.

Habitat. Unknown, coastal.

Type locality. Southern Atlantic Ocean, South Africa, Western Cape, Kleinbaai to Cape Agulhas .

Distribution. Known from type locality only.

Remarks. A single species of Eupolymnia had been previously described from Southern Africa, namely Eupolymnia capensis ( McIntosh, 1924) , from the Cape region. However, the original description is very poor and the diagnostic characters used for this genus, like the number and shape of lateral lobes, are not described. Moreover, in the absence of any illustrations, it is not possible to fully characterise this species. We suggest that Eupolymnia capensis is different from Eupolymnia scholastica sp. nov. as it was reported from a deep habitat (420 fathoms, i.e. 768 m) whereas the new species occurs in coastal environments. Eupolymnia capensis is characterised by the “extension of ventral scutes throughout the entire length”, which are “rugose” anteriorly. In Eupolymnia scholastica sp. nov., the ventral shields are present until SG XVI and they are smooth. The third pair of branchiae of Eupolymnia capensis is very small and restricted to a small terminal tuft while this third pair, although smaller, is well developed in Eupolymnia scholastica sp. nov. Finally, the uncini of Eupolymnia capensis have three teeth above the main fang while they only have two teeth for Eupolymnia scholastica sp. nov. Apparently, the type specimens were not deposited by McIntosh, neither in Iziko South African Museum's collection (Cape Town), nor in the Natural History Museum (London) or in the Gatty Marine Laboratory ( Scotland) where William McIntosh worked in the early 1920s’. Moreover, this species was not included in “Polychaetes of Southern Africa” by Day (1967) and we cannot find any other reference to E. capensis . In the absence of type material and the very brief description, we suggest that this species should be considered as nomen dubium.

These specimens were identified as E. nebulosa (Montagu, 1819) by John Day, a species described from UK and long considered cosmopolitan (Lavesque et al. 2021a).Although there are rare cases of wide distributions (i.e. about 5000 km) ( Hutchings et al., 2025; Lavesque et al. 2025) or the existence of a single species ( Thelepus japonicus Marenzeller, 1884 ) that has been introduced far from its native range ( Lavesque et al. 2020), the Spaghetti worms have restrictive distribution ranges with the existence of numerous cryptic species ( Nygren et al. 2018; Lavesque et al. 2019b; Lavesque et al. 2021b). Anyway, Eupolymnia scholastica sp. nov. differs from E. nebulosa by the presence of 15 ventral shields instead of 10 shields for E. nebulosa , the presence of an auricular lateral lobe on SG III which is bilobed for E. nebulosa and finally the presence of branchiae with well-developed branches instead of branchiae with few branches for E. nebulosa ( Capa & Hutchings 2006).

In the material examined, there was another potential undescribed species of Eupolymnia (SAM MB A020433) from Western Cap, Saint James Shore Station 34˚7’19.28”S, 18˚27’26.66”E, but the material is not well preserved and until additional material is collected, we are unable to describe it.