Phylladiorhynchus peneleos 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 peneleos

description: <i>Phylladiorhynchus peneleos</i> n. sp. (Figs. 39, 55F) <b>Type material.</b> <i>Holotype.</i> French Polynesia, Rapa. Stn 28, 27.6400°S, 144.3433°W, 30 m, 15 November 2002: ov. F 2.8 mm (MNHN-IU-2014-13734). <i>Paratypes.</i> French Polynesia. Society Islands, Moorea. Off E Opunohu pass, at Shark Feeding buoy, outer reef slope from within rubble, 17.4817°S, 149.8558°W, 17–18 m, 16 October 2008: 1 F 3.0 mm (UF15626).— Between Temae and Afarealtu. Outer reef slope, 17.5145°S, 149.761°W, 20 m, 23 October 2008: 1 ov. F 2.2 mm (UF36172), 1, ov. F 2.4 mm (UF16035), 1 M 2.0 mm (UF16078). Mariana Islands. Guam Island. Glass Breakwater. Near mouth of Apra harbour, among rocks, 3–6 m, 17 October 2001: 1 M 3.3 mm (UF1224). <b>Other material.</b> New Caledonia. Exp. Mont. Komac, 12 m, 7 October 1993: 1 F 2.0 mm (MNHN- IU-2016- 468). French Polynesia. Between Temae and Afarealtu. Outer reef slope, 17.4759°S, 149.8419°W, 11 m, 30 January 2012: 1 ov. F 2.1 mm (UF34661). <b>Etymology.</b> From the name <i>Peneleos</i>, an Argonaut, son of Hippalmus and Asterope. The name is considered a substantive in apposition. <b>Description.</b> <i>Carapace:</i> As long as or slightly longer than broad; transverse ridges with dense short setae. Gastric region with 4 transverse ridges: epigastric ridge distinct, with 2 median spines (rarely with some outer small spine or granules), short scales laterally; anterior protogastric ridge not medially interrupted, nearly extending laterally to carapace margin, sometimes followed by a posterior protogatric ridge; anterior mesogastric ridge not medially interrupted, laterally continuing to first branchial spine, followed by some short lateral scales; anterior metagastric ridge not medially interrupted, followed by some short scales. Mid-transverse ridge not interrupted, medially depressed, cervical groove indistinct, followed by 2–3 not interrupted or minutely interrupted ridges, interspersed with 1 short lateral ridge and few short scales. Lateral margins nearly straight or slightly convex, with 5 distinct spines: first anterolateral spine well-developed, reaching anteriorly to level of lateral orbital spine, second spine (hepatic) small, slightly dorsomesially from lateral margin, and followed by 3 branchial spines (2 anterior and 1 posterior). Rostrum leaf-like, horizontal, dorsally flattish, 1.6–[1.7] × as long as broad, length 0.3–[0.4] and breadth 0.2 that of carapace; lateral margins serrated and convex, with well-developed supraocular spines, subapical spines absent. Pterygostomian flap ending in sharp tooth, upper margin smooth. <i>Thoracic sternum</i>: As wide as long. Sternite 3 broad, 3.4–[4.0] × as wide as long, anterior margin serrated and convex, with a median projection, produced anterolaterally. Sternite 4 widely contiguous to sternite 3; anterolaterally serrated, surface depressed in midline, smooth; greatest width 1.3–[1.4] × that of sternite 3, [3.1]–3.2 × as wide as long. <i>Pleon</i>: Elevated ridges, with short setae and a few scattered long setae. Tergite 2 with anterior and posterior transverse; tergites 3–4 with anterior transverse ridge; tergites 5–6 smooth. <i>Eye:</i> Eyestalk length about [0.7]–0.8 × broader than long, peduncle distally setose, not distinctly expanded proximally; cornea expanded distally, maximum corneal diameter [1.0]–1.1 × rostrum width, 0.7–0.8 × maximum peduncle width. <i>Antennule</i>: Article 1 slightly longer than wide, with 5 distal spines: distomesial spine well-developed; proximal lateral spine small, always present. <i>Antenna:</i> Article 1 with prominent mesial process, nearly reaching end of proximal lateral antennular spine. Article 2 with well-developed distomesial and distolateral spines. Article 3 and 4 unarmed. <i>Mxp3:</i> Ischium with distinct distal spines on flexor and extensor margins. Merus 0.6–[0.7] × length of ischium, with well-developed distal spine on extensor and flexor margins. <i>P1</i> (lost in holotype): 2.8–3.8 (males), 2.3–2.4 (females) × carapace length; subcylindrical, spiny and with long stiff setae and dense thick iridescent and plumose setae; merus, carpus and palm with spines along mesial, dorsal and lateral surfaces, distal and mesial spines usually stronger than others. Merus 0.9–1.4 length of carapace. Carpus 1.7–1.9 × as long as wide. Palm 1.0–1.4 × carpus length, 2.0–2.5 × as long as broad. Fingers 0.6–1.0 × palm length; fixed finger with small basal spine; movable finger unarmed (large basal spine in 39F) fingers also extremely gaping. <i>P2–4</i>: Slender, densely setose and spinose. Meri successively shorter posteriorly: P3 merus 0.7–[0.8] × length of P2 merus, P4 merus [0.8]–0.9 × length of P3 merus. P2 merus, 0.7–[0.8] × carapace length, [4.0]–5.0 × as long as broad, [1.2] 1.3 × as long as P2 propodus; P3 merus 3.8–4 × as long as broad, [1.0]–1.1 × as long as P3 propodus; P4 merus 3.6–[3.6] × as long as broad, [1.0]–1.1 × 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, unarmed; flexor margin irregular, with distal spine on P2–3, distal spine absent in P4. Carpi with 1–3 spines on extensor margin on P2–3, unarmed on P4; distal spine prominent on P2–3, smaller on P4; granules below extensor margin on lateral surface of P2–4; flexor margin unarmed. Propodi moderately slender, [5.0–5.8]4.9–6.0 × as long as broad; extensor margin irregular, armed with 2–4 spines on proximal half; flexor margin with 3–4 slender movable spines in addition to distal pair. Dactyli 0.5–0.6 × length of propodi, ending in incurved, strong, sharp spine; flexor margin with 5–6 movable spines. <i>Eggs</i>: Ov. F carried approximately 6– 20 eggs of 0.3–0.4 mm diameter. <b>Live colour.</b> Body light orange, with dark orange-brownish small spots. P1 light orange, tip of fingers dark orange-reddish. P2–4 whitish, with dark orange-brownish bands. <b>Genetic data.</b> COI and 16S, Table 1. <b>Distribution.</b> Guam Island, French Polynesia and New Caledonia, between 3 and 30 m. <b>Remarks.</b> <i>Phylladiorhynchus peneleos</i> belongs to the group of species having 2 median epigastric spines, the hepatic margin armed with 1 spine, and 2 spines on the anterior branchial margin. The new species is morphologically close to <i>P. bahamut</i>, from the Red Sea. However, they can be distinguished by the following characters: - The gastric region has several secondary ridges in <i>P. peneleos,</i> whereas these ridges are absent in <i>P. bahamut</i>. - The carapace ridges have some iridescent thick setae in <i>P. bahamut,</i> whereas these setae are in <i>P. peneleos</i>. - Thoracic sternite 3 is broad, more than 3 × wider than long, in <i>P. peneleos</i>, whereas the sternite 3 is less than twice wider than long in <i>P. bahamut.</i> - The cornea is wider than the stalk in <i>P. peneleos,</i> whereas it is 0.7–0.8 × width of the eyestalk in <i>P. bahamut</i>. - The P1 has plumose setae in <i>P. peneleos,</i> whereas these setae are absent in <i>P. bahamut</i>. The genetic divergences between <i>P. peneleos</i> and <i>P. bahamut</i> were very high 32% (COI) and 14% (16S). The four-six sequences of <i>P. peneleos</i> from French Polynesia diverged 0.15% for COI and 0% for 16S respectively. The specimens of <i>P. peneleos</i> range from 2.0 to 3.3 mm postorbital carapace length.
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 102-104, DOI: 10.11646/zootaxa.5008.1.1, http://zenodo.org/record/5157455