Leptychaster kerguelenensis Smith 1876

• Main Authors: Romanelli, Mariela V., Tablado, Alejandro
• Format: Text
• Language: unknown
• Published: Zenodo 2011
• Subjects: Biodiversity; Taxonomy; Animalia; Echinodermata; Asteroidea; Paxillosida; Astropectinidae; Leptychaster; Leptychaster kerguelenensis; Antarctic; Kerguelen; Indian; Kerguelen Island; Sladen; Blunt Point; Antarc*; Antarctique*
• Online Access: https://dx.doi.org/10.5281/zenodo.5631985; https://zenodo.org/record/5631985

Leptychaster kerguelenensis Smith 1876 Figures 3 and 4 Leptychaster kerguelenensis Smith 1876, p. 110 Leptoptychaster kerguelenensis : Smith 1879, p. 278, pl. 17, fig. 2 Leptoptychaster kerguelensis : Koehler 1917, p. 52, pl. 6, figs. 1, 2, 7, 12 Leptoptychaster mendosus Koehler 1923, p. 98, pl. 12, figs. 3–5 Leptychaster kerguelenensis mendosus : Fisher 1940, p. 84. Compressed disc; rays five (R:r from 2.0–5.0); width of arms do not decreases along them but it do rapidly at distal end, ending as blunt point; madreporite obscured by abactinal paxillae (Fig. 3). Abactinal plates paxilliform, arranged irregularly, projecting proximal edges of plates lobed, reduced in size to the center of the disk and toward the midline of arms (near superomarginal plates from 2.3–2.7 mm size, carry 15– 33 spines from 0.1–0.2 mm long; center of disk and arms from 1.8 –2.0 mm size, carry 15–24 spines from 0.1–0.2 mm long) (Fig. 4 a and b). Superomarginal plates paxilliform, similar but larger than abactinals (from 2.9–3.2 mm size, carry 20–32 spines 0.1–0.2 mm long), and separates from inferomarginal ones by a well-defined groove (Fig. 4 c). Inferomarginal plates tall, short, forming vertical edge of body; with prominent metapaxillar ridge raised transversally to the ambulacral groove (from 1.2–1.7 mm tall and from 0.3–0.5 mm wide) in middle of the ray, carry on top of the ridge 43–61 spines, 0.2–0.3 mm long, arranged irregularly (Fig. 4 e). Slope of ridge carry small, thin and delicate hairlike spinules, parallel to base plate, and interlaced spinules forms fasciolar grooves between contiguous inferomarginal plates (Fig. 4 f). Small triangular actinal area with small paxilliform plates, arranged in a few rows from the mouth to distal end of arm (from 0.7–0.8 mm size, carry 12–22 spines 0.3–0.4 mm long). Only one row of actinal plates is present between furrow and margin in the most part of the arm (Fig. 4 g). Adambulacral plates are widely spaced, consecutive plates being united by broad ligamentous bands. Each plate carry 6–10 spines, 2 furrow spines (from 1.3–1.4 mm long) and 4–8 subadambulacrals spines (from 0.9–1.2 mm long) (Fig. 4 d). Oral plates elongate (from 2.9–3.3 mm long and 0.4–0.5 mm wide), 6–9 oral spines in each oral plate and 10–20 suboral spines (the oral ones are longer than the suboral) (Fig. 4 h). Distribution. Southern Indian Ocean platform (Subantarctic convergence) surrounding the Kerguelen and Marion islands, 55–182 m depth; Southwestern Atlantic platform between 48 ° to 55 ° S; from 86–152.5 m depth (Fig. 5). Remarks. The above redescription is based on previous descriptions (Sladen 1889, Koehler 1923) and the study of MACN-In specimens, with sizes ranging R from 12–66 mm and r from 2–16 mm. : Published as part of Romanelli, Mariela V. & Tablado, Alejandro, 2011, Leptychaster kerguelenensis (Echinodermata: Asteroidea) from Southwest Atlantic: Redescription and geographic distribution, pp. 59-68 in Zootaxa 2971 on pages 64-66, DOI: 10.5281/zenodo.201534 : {"references": ["Smith, E. A. (1876) Descriptions of species of Asteriidae and Ophiuridae from Kerguelen Island. Annals and Magazine of Natural History, 17 (4), 105 - 113.", "Smith, E. A. (1879) Echinodermata of Kerguelen Island. Philosophical Transactions of the Royal Society, 168, 270 - 281.", "Koehler, R. (1917) Echinodermes (Asteries, Ophiures et Echinides) recueillis par M. Rallier de Baty, aux de Kerguelen, en 1913 - 14. Annals de l\u00b4Institut Oceanographique, Monaco, 7 (8), 1 - 82.", "Koehler, R. (1923) Asteries et Ophiures recueillis par l'expedition antarctique suedoise, 1901 - 03. Further Zoological Results of the Swedish Antarctic Expedition, 1 (1), 1 - 145.", "Fisher, W. K. (1940) Asteroidea. Discovery Reports, 20, 69 - 306.", "Sladen, W. P. (1889) The Asteroidea. Report of Scientific Results of the Exploring Voyage of H. M. S. Challenger, Zoology, 30, 1 - 935."]}