Achelia gracilis Verrill 1900
Creators: name: Sabroux, Romain
name: Hassanin, Alexandre
name: Corbari, Laure
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Pycnogonida
Pantopoda
Ammotheidae
Achelia
Achelia gracilis

description: Achelia gracilis Verrill, 1900
Achelia (?) gracilis Verrill, 1900: 582, pl. 70 fig. 10.
Ammothea gracilis – Cole 1904a: 317–323, pl. 21 figs 4–14. — Helfer & Schlottke 1935: 285. Ammothea (Achelia) gracilis – Giltay 1934b: 5.
Achelia gracilis – Marcus 1940: 79. — Hedgpeth 1948: 244. — Stock 1954a: 117; 1975a: 983; 1979: 10; 1986: 416, tab. 1; 1992a: 139 (list). — Bourdillon 1955: 597. — Müller 1992b: 43, fig. 1. — Child 1996a: 526. — Müller & Krapp 2009: 10–11, 14 (key), 14–17, 137 (list), tab. 1, figs 2–3. — Varela 2012: 2, fig. 1a. — Lucena & Christoffersen 2018a: 104. — Lucena et al. 2019: 3 (list), 20–21, figs 2a–c, 3–4. — Sabroux et al. 2019b: tab. 1, figs 3, 5. — León-Espinosa et al. 2021: tab. 1. — Ramírez-Tello et al. 2022: tab. 1.
Achelia (Pigrolavatus) gracilis – Fry & Hedgpeth 1969: 104, figs 152–153, 155.
Type material
Holotype: YPM IZ 003366.CR (not examined). Type locality: Flatts Inlet, Bermuda.
Material examined
MARTINIQUE • 1 ♂; Grande Anse d’Arlets; 14°29.9ʹ N, 61°05.4ʹ W; depth 28 m; 7 Sep. 2016; st. AB157; MNHN-IU-2016-849/ MK411162 • 1 ♂; Grande Anse d’Arlets; 14°30.5ʹ N, 61°06.1ʹ W; depth 20–23 m; 6 Sep. 2016; st. AB152; MNHN-IU-2016-851/ MK411164 • 1 ♂; same collection data as for preceding; MNHN-IU-2016-888/ MK411197 • 1 juv.; Baie de Fort-de-France; 14°32.6ʹ N, 61°04.7ʹ W; depth 0–1 m; 6 Sep. 2016; st. AM002; MNHN-IU-2016-85/ MK411170 • 1 ♂ ov.; same collection data as for preceding; MNHN-IU-2016-1193 • 1 ♂; Presqu’Île de la Caravelle; 14°44.1ʹ N, 60°50.8ʹ W; depth 16 m; 18 Sep.2016;st.AB189;MNHN-IU-2016-881/ MK411191 • 1♂; Ste-Marie, 14°46.3ʹ N, 60°57.5ʹ W; depth 20 m; 20 Sep. 2016; st. AB260; MNHN-IU-2016-1062/ MK411040 • 1 juv.; Les Anses-d’Arlet; 14°29.7ʹ N, 61°05.4ʹ W; depth 19 m; 7 Sep. 2016; st. AB155; MNHN-IU-2016-1114/ MK411053 • 1 ♀ gr.; E of Le Vauclin; 14°34.7ʹ N, 60°45.9ʹ W; depth 22 m; 16 Sep. 2016; st. AB181; MNHN-IU-2016-1180/ MK411073 • 1 ♀ gr.; Le Robert; 14°41.1ʹ N, 60°51.4ʹ W; depth 10 m; 19 Sep. 2016; st. AB195; MNHN- IU-2016-1182 • 1 ♂; same collection data as for preceding; MNHN-IU-2016-1330/ MK411104 • 2 ♂♂, 1 juv.; same collection data as for preceding; MNHN-IU-2016-1408 • 1 ♀; Trois Rivières; 14°27.7ʹ N, 60°57.8ʹ W; depth 4–5 m; 25 Sep. 2016; st. AB354; MNHN-IU-2016-1276/ MK411095 • 1 ♀ gr.; same collection data as for preceding; MNHN-IU-2016-1380/ MK411108 • 1 ♂ ov.; Presqu’Île de la Caravelle; 14°48.4ʹ N, 60°52.8ʹ W; depth 23–25 m; 20 Sep. 2016; st. AB197; MNHN-IU-2016-1379/ MK411107 • 1 juv.; same collection data as for preceding; MNHN-IU-2016-1384.
Remarks
This species was distinguished from Achelia sawayai Marcus, 1940 based on the key in Müller & Krapp (2009), relying on the number of palp articles (7 in A. gracilis, 8 in A. sawayai) and the number of dorsolateral tubercles on coxae 1 on the first and second legs of males (4 in A. gracilis, 3 in A. sawayai). Achelia gracilis was previously recorded from Martinique by Bourdillon (1955) on the hulls of scows in Fort-de-France port. Madibenthos sampling reveals that this species is present on both the Atlantic and Caribbean coasts of Martinique. Achelia gracilis is a common species in the Caribbean, almost as common as its close congener, Achelia sawayai (Child 1996a).
DNA barcoding data (Sabroux et al. 2019b) suggest that this species name hides two potential cryptic species (intracluster p-distance = 0–0.010; intercluster p-distance = 0.105 –0.112), here named group 1 (MNHN-IU-2016-849, -851, -857, 881, -888, -1114, -1180, -1276, -1379 and -1380) and group 2 (MNHN-IU-2016-1062 and -1330) (Table 2 and Appendix).
Distribution
Tropical West Atlantic (Bermuda, Caribbean and Brazil).
Depth range
0– 18 m. One record at 157 m is regarded as a likely contamination by shallow fouling on the hull of a ship. We extend this depth-range to 28 m.
description: Published as part of Sabroux, Romain, Hassanin, Alexandre & Corbari, Laure, 2022, Sea spiders (Arthropoda: Pycnogonida) collected during the Madibenthos Expedition from Martinique shallow waters, pp. 1-141 in European Journal of Taxonomy 851 (1) on pages 8-9, DOI: 10.5852/ejt.2022.851.1999, http://zenodo.org/record/7428095