Glyptoxanthus labyrinthicus Stimpson 1860
Creators: name: Mendoza, Jose Christopher E.
name: Guinot, Danièle
Publisher: name: Zenodo
Year: 2011
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Xanthidae
Glyptoxanthus
Glyptoxanthus labyrinthicus

description: Glyptoxanthus labyrinthicus (Stimpson, 1860)
(Figs. 7, 10 F)
Actaea labyrinthica Stimpson, 1860: 204 [76] (type locality: Panama).
Glyptoxanthus labyrinthicus, A. Milne-Edwards 1879: 255, pl. 43 fig. 4. — Rathbun 1930: 266 (in part), pl. 108 figs. 1-3. — Garth 1939: pl. 4 fig. 2, pl. 5, figs. 1b, 2b, 3b. — Guinot 1967: 556; 1971: 1072; 1979: 68, pl. 6 fig. 4. —Ng et al. 2008: 199 (list).
Material examined. Panama: Neotype (presently designated), female, 31.1 × 21.7 mm (USNM 1083419), Bella Vista, Panama Bay, Gulf of Chiriqui.
Other material. 1 female, 10.4 × 7.2 mm (LACM CR 1941.3721), stn 104, 8– 10 m (4.5–5.5 fms), Guayabo Chiquito, coll. Askoy Expedition, 20–21 May 1941; 1 male, 19.9 × 13.6 mm (USNM 20604), Pacific coast of Panama, coll. Albatross, 12 Mar. 1891; 3 males, 28.5 × 19.7 mm —52.8 × 35.8 mm, 3 females, 33.8 × 23.5 mm —53.2 × 37.0 mm, 1 ovig. female, 40.5 × 28.3 mm (USNM 284119), Pacific coast of Panama, coll. E.D. Robson, det. J.S. Garth.
Colombia: 1 male, 19.0 × 12.8 mm (LACM CR 1935.0753), stn 435-35, Octavia Bay, coll. A. Hancock Pacific Expedition, Velero, 28 Jan. 1935.
Mexico: 1 female (dry), 45.1 × 32.2 mm (MNHN-B4260), Pacific coast, no other data.
Diagnosis. Carapace transversely ovate, width-to-length ratio 1.4–1.5; regions well defined, intervening furrows similarly wide, setose; 2M completely divided longitudinally, inner branch fused to 1M and posterior part of 3M; 4M bridging 3M to 1P; 2L, 3L, 4L distinct, 5L and 6L fused; 2P transversely X-shaped, entire; vermiculations generally smooth, anfractuous, punctate. Anterolateral margin arcuate, divided into moderately produced lobes, fourth most distinct, subtriangular. Male thoracic sternum eroded, but with symmetric pattern of ridges and cavities. External surfaces of pereopods similarly sculpted as dorsal carapace. Male abdomen with transverse ridges. G1 long and slender, tip bluntly rounded, devoid of setae, studded with spiniform granules; G2 one-fourth length of G1.
Remarks. Stimpson (1860) described Actaea labyrinthica from the Pacific coast of Panama. This species was later transferred by A. Milne-Edwards (1879) to Glyptoxanthus. Rathbun (1930: 266) reported that Stimpson’s type specimen was no longer extant, but did not designate a neotype. A female specimen (31.1 × 21.7 mm, USNM 1083419), collected from Bella Vista, on the Pacific coast of Panama is here designated as neotype, in accordance with Article 75 of the Code. This action is necessary to stabilize the taxonomy of this species and to avoid confusion with a similar species also known from the eastern Pacific, G. hancocki.
Glyptoxanthus labyrinthicus is morphologically most similar to G. hancocki Garth, 1939, particularly in the general form and sculpturing of the carapace and thoracic sternum, but a closer examination reveals some consistent differences between the two species (see Remarks on G. hancocki). Stimpson (1860) (see Rathbun, 1930: 266) described the live colouration of this species as “variegated with yellow and carmine.” A recent photograph of the same species collected in Panama (kindly provided by Dr. Arthur Anker) shows the vermiculations to be generally variegated with rose-pink, orange and lavender, with bold splotches of darker purple on the posterior branchials, parts of the cardiac and intestinal regions, and on the pereopods, and a vivid vermillion on the anterior parts of the inner halves of the 2M region; the grooves, as well as the edges of the ambulatory legs are filled with light-brown setae.
Ecology and geographical distribution. Glyptoxanthus labyrinthicus has been reported from the Pacific coast of the Americas, particularly from Panama (type locality), Colombia, and Mexico.
description: Published as part of Mendoza, Jose Christopher E. & Guinot, Danièle, 2011, Revision of the genus Glyptoxanthus A. Milne-Edwards, 1879, and establishment of Glyptoxanthinae nov. subfam. (Crustacea: Decapoda: Brachyura: Xanthidae), pp. 29-51 in Zootaxa 3015 on pages 41-43, DOI: 10.5281/zenodo.207310