Phylladiorhynchus iphiclus Rodríguez-Flores &amp; Macpherson &amp; Machordom 2021, n. sp.
Creators: name: Rodríguez-Flores, Paula C.
name: Macpherson, Enrique
name: Machordom, Annie
Publisher: name: Zenodo
Year: 2021
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Decapoda
Galatheidae
Phylladiorhynchus
Phylladiorhynchus iphiclus

description: <i>Phylladiorhynchus iphiclus</i> n. sp. (Figs. 20, 21G) <b>Type material.</b> <i>Holotype</i>. French Polynesia. BENTHAUS Stn DW 1894, 27.6688°S, 144.3585°W, 100 m, 8 November 2002: ov. F 2.3 mm (MNHN- IU-2019-2662). <i>Paratype</i>. Vanuatu, SANTO, no station: 1 M broken (MNHN-IU-2019-2651). <b>Etymology.</b> From the name <i>Iphiclus</i>, an Argonaut, son of Phylacus and Clymene. The name is considered a substantive in apposition. <b>Description.</b> <i>Carapace:</i> as long as broad; transverse ridges scattered and indistinct, without setae. Gastric region flattened and smooth, transverse ridges barely distinct: epigastric ridge indistinct, with 2 median spines; 2 lateral scales on anterior protogastric region. Mid-transverse ridge not interrupted, medially depressed, preceded by distinct cervical groove, followed by 1 not medially interrupted ridge and 1 short lateral ridge. Lateral margins slightly convex, with 4 spines: first anterolateral spine well-developed, reaching end of lateral orbital spine, hepatic margin unarmed; anterolateral spine followed by 3 branchial spines (2 anterior and 1 posterior spines). Rostrum triangular, horizontal, dorsally flattish or slightly concave, 1.2–[1.3] × as long as broad, length0.3 and breadth0.3 that of carapace; lateral margins smooth and straight, with well-developed supraocular spines, subapical spines absent. Pterygostomian flap ending in round, upper margin smooth. <i>Thoracic sternum</i>: As wide as long. Sternite 3 moderately broad, [2.2]–2.5 × as wide as long, anterior margin with obtuse median projection, anterolaterally rounded. Sternite 4 widely contiguous to sternite 3; surface depressed in midline, smooth; greatest width 2.1–[2.3] × that of sternite 3, 2.8–[3.2] × as wide as long. <i>Pleon</i>: Transverse ridges with a few scattered short setae. Tergites 2–3 with anterior transverse ridge only; tergites 4–6 smooth. <i>Eye:</i> Eyestalk as broad as long, peduncle not setose, cornea very expanded distally, maximum corneal diameter 1.3 × rostrum width, [1.2]–1.3 × maximum peduncle width. <i>Antennule</i>: Article 1 1.3 × longer than wide, with 4 spines: distomesial spine small, distolateral spines with a blunt process or granule (no double or very small distolateral spine); proximal lateral spine small, always present. <i>Antenna:</i> Article 1 with prominent mesial process distally clearly not reaching lateralmost antennular spine. Article 2 with distinct distal spines laterally and mesially. Article 3 with distomesial spine. Article 4 unarmed. <i>Mxp3:</i> Ischium with distinct distal spines on flexor and extensor margins. Merus [0.7] × length of ischium, extensor margin unarmed, flexor margin with 3 spines, decreasing in size distally. <i>P1:</i> 2.8 male, [2.5] (female) × carapace length; subcylindrical, spiny and with scattered long stiff setae and some thick iridescent setae; merus, carpus and palm with spines along mesial, dorsal and lateral surfaces, distal and mesial spines usually stronger than others. Merus as long as carapace, 1.5–[1.7] × as long as carpus. Carpus 1.8– [2.5] × as long as wide. Palm 0.8–[0.9] × carpus length, [1.5]–1.6 × as long as broad. Fingers as long as palm length, fixed finger with distal spine on lateral margin; movable finger with 2 basal spines. <i>P2–4:</i> Slender, subcylindrical, moderately setose and spinose. Meri successively shorter posteriorly: P3 merus 0.8–[0.9] × length of P2 merus, P4 merus [0.8]–0.9 × length of P3 merus. P2 merus, [0.8] or as long as carapace length, [5.2]–5.4 × as long as broad, 1.3–[1.5] × as long as P2 propodus; P3 merus 5–[5.3] × as long as broad, 1.1–[1.6] × as long as P3 propodus; P4 merus 4–[4.8] × as long as broad, 1.1–[1.2] × as long as P4 propodus; extensor margin of P2 and P3 with row of spines, proximally diminishing, with prominent distal spine; P4 extensor margin irregular but unarmed other than small distal spine; flexor margins of all legs irregular, with distal spine; P4 lateral surface with median row of 2 small spines, absent in others. Carpi with 2 spines on extensor margin on P2–3, unarmed on P4; distal spine prominent on P2–3, smaller on P4; flexor margin unarmed. Propodi slender, [5.0–5.5]5.6–7.0 × as long as broad; extensor margin irregular, usually armed with a 1–2 proximal spines on P2–4; flexor margin with 3–4 slender movable spines in addition to distal pair. Dactyli 0.6–[0.7] × length of propodi, ending in incurved, strong, sharp spine; flexor margin with 4–6 movable spines. <i>Eggs</i>: Ov. F (MNHN- IU-2019-2662) carried 10 eggs of 0.4 mm diameter <b>Live colour.</b> Unknown. <b>Genetic data.</b> No data. <b>Distribution.</b> French Polynesia and Vanuatu, 100 m. <b>Remarks.</b> <i>Phylladiorhynchus iphiclus</i> is easily distiguished from the other species by having the Mxp3 merus with 3 prominent spines along the flexor margin, the rostrum triangular and 2 spines on the epigastric ridge. <i>Phylladiorhynchus iphiclus</i> resembles to <i>P. boucheti</i>, from Chesterfield Islands, however, they can be distinguished by the following characters: - The epigastric ridge has 2 spines in <i>P. iphiclus</i>, whereas there are 4 spines in <i>P. boucheti</i>. - The gastric ridges are obsolescent or absent in <i>P. iphiclus</i>, whereas the protogastric and mesogastric ridges are distinct in <i>P. boucheti</i>. - The carapace anterior margin has 2 spines in <i>P. iphiclus</i>, whereas there are 3 spines in <i>P. boucheti</i>. - The flexor margin of Mxp3 merus is armed with 3 spines, whereas there are 2 spines in <i>P. boucheti</i>. Furthermore, the extensor margin is unarmed in <i>P. iphiclus</i>, having a distal spine in <i>P. boucheti</i>.
description: Published as part of <i>Rodríguez-Flores, Paula C., Macpherson, Enrique &amp; Machordom, Annie, 2021, Revision of the squat lobsters of the genus Phylladiorhynchus Baba, 1969 (Crustacea, Decapoda, Galatheidae) with the description of 41 new species, pp. 1-159 in Zootaxa 5008 (1)</i> on pages 58-59, DOI: 10.11646/zootaxa.5008.1.1, http://zenodo.org/record/5157455