Thelepus fraggleorum Capa & Hutchings, 2006, sp. nov.
Creators: name: Capa, María
name: Hutchings, Pat A.
Publisher: name: Zenodo
Year: 2006
Subjects: Biodiversity
Taxonomy
Animalia
Annelida
Polychaeta
Terebellida
Terebellidae
Thelepus
Thelepus fraggleorum

description: Thelepus fraggleorum sp. nov.
Figures 2 Q–T, 7A–I
Thelepus setosus: López et al. 1997: 61; NOT T. setosus (Quatrefages, 1865). Type locality. Panama, Coiba National Park, Jicarita Island.
Material examined. Panama, Coiba National Park. Holotype: MNCN 16.01/10529, Jicarita Island, 7º37'50''N 81º44'30''W, in gorgonians, 15 m, 7 Feb. 1997. Paratypes — MNCN 16.01/10530 same sample (5 spec.) — USNM 1093378, same sample (3 spec.) — AM W29702, same sample (3 spec.) — MNCN 16.01/10531, Santa Cruz Islet, 7º38'00''N 81º47'20''W, driftwood, 21 Jun. 1996 (3 spec.) — AM W29708, same sample (SEM stub).
Description. Holotype complete, 30 mm long and 3 mm maximum width, 97 segments, 70 of which notochaetigerous, posterior 24 with neuropodia only. Preserved material pinkish in colour. Buccal tentacles numerous, long, especially dorsal ones. Tentacular membrane with thick margin (Figure 7 A). Small eyespots arranged irregularly in 3–4 rows. Upper lip rounded and directed anteriorly, lower lip half length of upper lip, flattened (Figure 7 B, C). Lateral lobes absent (Figure 7 B). Three pair of branchiae on segments 2–4 with numerous weakly-curled filaments of similar size; wide gap separating left and right group of filaments (Figure 7 A, B); first pair with 10 filaments, second pair with 15 and third pair with 7 on each side. All branchial filaments arise dorsally with no lateral extension. Nephridial papillae not seen. Eighteen ventral pads, in contact with neuropodial tori, diminishing in width posteriorly (Figure 7 C). Posterior segments as long as wide, becoming progressively more compact towards pygidium. Notopodia present on segments 3–73, elongated, with two kinds of chaetae within each fascicle arranged in two transverse rows, both diminishing in length dorsoventrally. Superior row with short and bilimbate chaetae (Figure 7 D, H), inferior row with long and bilimbate chaetae (Figure 7 H). Neuropodia from segment 5, with tori increasing in width on first two or three segments (Figure 7 E) and slightly decreasing in width posteriorly; posterior chaetigers with elevated tori (Figure 7 I). Uncini arranged in one single row, with two large teeth above main fang and single smaller tooth between on anterior segments and dental formula MF: 2:1 (Figures 2 Q, R, 7F); posteriorly some additional small teeth may be present (MF:2:1–3) (Figures 2 S, T, 7G). Pygidium with nine papillae surrounding medial anus. Tube not seen.
Var ia t io n. Only one of the paratypes is complete and measures 35 mm long, with 77 chaetigers (MNCN 16.01/10530). Some paratypes lack eyespots, but these may have been lost due to storage in alcohol. Number of branchial filaments varies with size of specimen, with 15–19 on first pair (10 in holotype), 9–15 on second and 7–10 on third on each side respectively; length of branchial filaments similar on all specimens. Notopodia absent on posterior last quarter of segments which possess only neuropodia. Posterior segments compact.
Remarks. Previously known species of Thelepus with three pairs of branchiferous segments are discussed in Hutchings and Glasby (1987). The T. fraggleorum sp. nov. specimens were previously identified by López et al. (1997) as T. setosus (Quatrefages, 1865), a species described from France, and previously recorded from the Panamanian Atlantic coast by Fauchald (1977). Type material of T. setosus is not known to be deposited in any museum. Hutchings and Glasby (1987) suggested that some of the “cosmopolitan” species records of T. setosus were almost certainly misidentifications. T. fraggleorum sp. nov. shares some character states with T. setosus such as the presence of eyespots, similar numbers of branchial filaments and similar dental formula (two rows of teeth above the main fang). T. fraggleorum sp. nov. has a broad gap between the two pairs of branchiae, while T. setosus has a small dorsal gap between the two pairs (fide Hutchings & Glasby 1987). Notopodia are present on most segments on T. fraggleorum sp. nov., but are only present on the first half of the body in T. setosus (fide Hutchings & Glasby 1987). In addition T. fraggleorum sp. nov. typically have an unpaired tooth in the second row of teeth above main fang on uncini of anterior segments (MF:2:1) while T. setosus has second rows with paired teeth (MF:2:0–2).
Thelepus fraggleorum is distinguished from T. haitiensis Treadwell, 1931, a Caribbean species, by the number of branchial filaments, always less than 20 in the new species and greater than this number in T. haitiensis, and in the dental formula of uncini, always with some third row teeth in T. fraggleorum, but always MF: 2 in T. haitiensis.
Etymology. This species is dedicated to the Fraggles, incredible creatures that live in Fraggle Rock and that share some similarities with this new species.
description: Published as part of Capa, María & Hutchings, Pat A., 2006, Terebellidae (Polychaeta) from Coiba National Park, Panamanian Pacific, including description of four new species and synonymy of the genus Paraeupolymnia with Lanicola, pp. 1-29 in Zootaxa 1375 on pages 23-26, DOI: 10.5281/zenodo.174977