Phylladiorhynchus marina, Rodríguez-Flores & Macpherson & Machordom, 2021

Rodríguez-Flores, Paula C., Macpherson, Enrique & Machordom, Annie, 2021, Revision of the squat lobsters of the genus Phylladiorhynchus Baba, 1969 (Crustacea, Decapoda, Galatheidae) with the description of 41 new species, Zootaxa 5008 (1), pp. 1-159 : 88-89

Phylladiorhynchus marina n. sp.

( Figs. 33D , 34 , 55B )

Type material. Holotype. Vanuatu, SANTO Stn DB 14, 15.5150°S, 167.18333°E, 10–14 m, 13 October 2006: ov. F 2.0 mm (MNHN-IU-2014-13887).

Paratypes. Vanuatu. SANTO Stn DS 6 light, 15.5150°S, 167.18333°E, 8–15 m, 11 September 2006: 1 M 1.4 mm, 3 ov. F 1.7–1.8 mm (MNHN-IU-2014-13893).― Stn FR 2, 15.5550°S, 167.1466°E, 1–25 m, 11 September 2006: 1 F 1.8 mm (MNHN-IU-2014-13889).― Stn DB 16, 15.591667°S, 167.2633°E, 32–40 m, 14 September 2006: 1 M 1.5 mm (MNHN-IU-2014-13891).― Stn DB 40, 15.4966°S, 167.2516°E, 5 m, 19 September 2006: 3 M 1.5–1.6 mm (MNHN-IU-2019-2646), 1 ov. F 1.5 mm (MNHN-IU-2016-453), 1 F 1.6 mm (MNHN-IU-2014-13862) .

Other material. Vanuatu. SANTO Stn DB 46, 15.4800°S, 167.2533°E, 2–3 m, 20 September 2006: 1 F 1.7 mm (MNHN-IU-2019-2644).― Stn DB 53, 15.4800°S, 167.2533°E, 5 m, 22 September 2006: 5 M 1.4–1.8 mm, 11 ov. F 1.2–1.8 mm, 5 F 1.3–2.1 mm (MNHN-IU-2019-2652), 8 M 1.2–1.5 mm, 3 ov. F 1.7–2.0 mm, 1 F 1.4 mm (MNHN-IU-2019-2645).― Stn AT 42, 15.6250°S, 167.0383°E, 112-148 m, 28 September 2006: 1 M 1.4 mm (MNHN-IU-2014-13895).― Stn NS 36, 15.5283°S, 167.1583°E, 2–3 m, 2 October 2006: 1 ov. F 1.5 mm (MNHN-IU-2014-13806).― Stn FB 40, 15.3816°S, 167.1950°E, 9 m, 29 September 2006: 1 postlarvae 1.6 mm (MNHN-IU-2014-13876).― Stn DB 83, 15.7233°S, 167.2500°E, 6 m, 3 October 2006: 1 M 1.4 mm (MNHN- IU-2014-13892).― Stn DS 91, 15.5616°S, 167.1400°E, 7 m, 6 October 2006: 2 M 1.4–1.5 mm, 1 ov. F 2.3 mm (MNHN-IU-2014-13888).― Stn FB 56, 15.5866°S, 167.0350°E, 3–18 m, 7 October 2006: 1 ov. F 1.6 mm (MNHN- IU-2014-13896).― Stn EP 34, 15.5550°S, 167.2150°E, 40–60 m, 14 October 2006: 1 ov. F 1.5 mm (MNHN-IU- 2019-2647).― Stn EP 36, 15.5550°S, 167.3226°E, 20–60 m, 14 October 2006: 2 M 1.4–2.2 mm, 1 ov. F 1.9 mm (MNHN-IU-2019-2650), 4 M 1.4–1.8 mm, 3 ov. F 1.9–2.2 mm, 1 F 1.4 mm (MNHN-IU-2019-2649), 1 M 1.5 mm, 1 ov. F 2.0 mm, 4 F 1.6–2.3 mm (MNHN-IU-2019-2653).― Stn LD 31, 15.5716°S, 167.1983°E, 1–3 m, 14 October 2006: 2 ov. F 2.4–2.6 mm (MNHN-IU-2014-13890).― Stn FB 80, 15.5516°S, 167.1600°E, 2 m, 14 October 2006: 1 F 1.7 mm (MNHN-IU-2014-13894).― Stn LD 35, 15.5466°S, 167.1933°E, 3–8 m, 16 October 2006: 2 M 1.4- 2.3 mm, 3 ov. F 1.3–2.1 mm, 1 F 2.2 mm (MNHN-IU-2014-13897).―SE corner of Espiritu Santo Island (mixed illegible or confused labels) Sep/ Oct 2006: 5 F 1.7–2.1 mm (MNHN-IU-2019-2648) .

Etymology. Named in memorian of Marina Alcobendas, from the Museo Nacional de Ciencias Naturales, Madrid, evolutionary biologist and dear colleague. The name is considered as a substantive in apposition

Description. Carapace: Robust or massive, sexually dimorphic (wider on females), 0.9–1.2 (males), [0.8]–0.9 (females) × as long as broad; transverse ridges elevated, upraised dorsally, with few short setae and scattered long thick plumose setae. Gastric region convex (upraised) with some transverse ridges: epigastric ridge unarmed, scalelike, often undistinct; anterior protogastric ridge not medially interrupted, laterally interrupted with few scales, often followed by few short scales; anterior mesogastric ridge scale-like, laterally interrupted by anterior branch of cervical groove, continuing with few scales, often followed by few short scales; anterior metagastric ridge medially uninterrupted, followed by few scales on posterior metagastric region. Mid-transverse ridge not interrupted, cervical groove distinct, followed by 2 not interrupted or minutely interrupted ridges, interspersed with 1 laterally interrupted or scale-like ridge and 1–2 short lateral ridges. Lateral margins clearly convex, with 7–8 spines: first anterolateral spine well-developed, exceeding lateral orbital spine, second spine (hepatic) minute, often obsolescent in males, slightly dorsomesially from lateral margin, and followed by 5–6 branchial spines (3 anterior and 2–3 posterior). Rostrum leaf-like, horizontal, dorsally slightly or deeply concave, [1.5]1.6–1.9 × as long as broad, length [0.4]0.3– 0.5 and breadth [0.2]–0.3 that of carapace; lateral margins minutely serrated and convex, with well-developed supraocular and subapical spines (trispinose). Pterygostomian flap ending in blunt tooth; upper margin unarmed.

Thoracic sternum:Sternite3moderately broad,[1.8]–1.9×as wide as long, anterior margin convex,anterolaterally rounded. Sternite 4 widely contiguous to sternite 3; surface flattened, smooth; greatest width [2.5]3.0–3.1 × that of sternite 3, 2.0–[2.1] × as wide as long.

Pleon: Elevated ridges upraised dorsally, with few short setae.Tergites 2–4 with anterior and posterior transverse elevated ridges; tergites 5–6 smooth.

Eye: Eyestalk length about 1.0 × broader than long, peduncle distally setose, not distinctly expanded proximally; maximum corneal diameter 0.9–[1.0] × rostrum width, as wide as eyestalk.

Antennule: Article 1 longer than wide, with 3–4 distal spines: distomesial spine small or obsolescent; proximal lateral spine absent.

Antenna: Article 1 with prominent mesial process, distally not reaching lateral antennular spine. Article 2 often with minute distal spines laterally and mesially. Articles 3 and 4 unarmed.

Mxp3: Ischium with distinct distal spines on flexor and extensor margins. Merus [0.6] × length of ischium, with 1 well-developed distal spine on extensor margin and 2 spines on flexor margin, proximal spine slightly larger than distal.

P1: 2.0 × carapace length (males), [1.3]–1.6 (females), subcylindrical, with scattered spines and long stiff setae; merus and carpus with spines along mesial, dorsal and lateral surfaces, distal and mesial spines usually stronger than others. Merus [0.5]–1.0 length of carapace, [1.5]–2.1 × as long as carpus. Carpus 1.5–[2.0] × as long as wide. Palm [0.7]–0.9 × carpus length, [1.4]1.2–1.5 × as long as broad with scattered small spines on dorsal and ventral surfaces, lateral and mesial margins irregular, with 1 small spine on distomesial margin. Fingers unarmed, 1.0–[1.1]× palm length.

P2–4: Moderately stout, setose and moderately spinose. Meri successively shorter posteriorly: P3 merus 0.8– [0.9] × length of P2 merus, P4 merus 0.7–[0.9] × length of P3 merus. P2 merus [1.5]1.7–2.4 × carapace length, [4.0]–4.2 × as long as broad, 1.3 × as long as P2 propodus; P3 merus [3.5]–3.6 × as long as broad, [1.1]–1.2 × as long as P3 propodus; P4 merus [2.5]3.0–3.3 × as long as broad, as long as P4 propodus; extensor margins of P2 and P3 with row of few small spines, proximally diminishing in size, with well-developed distal spine; P4 extensor margin irregular but unarmed; flexor margins irregular, with distal spine on P2–3, absent in P4. Carpi with 1 spine on extensor margins of P2 and often in P3, unarmed on P4; distal spine prominent on P2–3, absent on P4; row of small spines below extensor margin on lateral surface of P2 and may be present on P3?, unarmed on P4. Propodi stout, [4.5–5.0]4.4–4.5 × as long as broad; extensor margins irregular, usually unarmed; flexor margins with 3–4 slender movable spines in addition to distal pair. Dactyli [0.8]–0.9 × length of propodi, ending in incurved, strong, sharp spine; flexor margins with 5–6 well-developed dactylar spines, each with 1 spinule.

Eggs: Ov. F carried approximately 7– 25 eggs of 0.3–0.4 mm diameter.

Live colour. Body brownish, with brown patches and spots. P1–4 pale brown, with dark spots and bands.

Genetic data. COI and 16S, Table 1.

Distribution. Vanuatu, between 2 and 148 m.

Remarks. Phylladiorhynchus marina belongs to the group of species having the epigastric ridge unarmed, the carapace and pleon ridges elevated, upraised, and dactylar spines on the flexor margins of the dactyli. The new species is closely related to P. phanus from Papua New Guinea (see the differences under the Remarks of this species).

The specimen of P. marina range from 1.2 to 2.6 mm size postorbital carapace length. The two sequences of P. marina from Vanuatu diverged 0.8% for COI and 0.8% for 16S.

Figures

FIGURE 33. Rostrum, dorsal view. A, Phylladiorhynchus laureae n. sp., paratype female 1.7 mm (MNHN-IU-2019-2635). B, P. lini n. sp., holotype female 2.2 mm. C, P. lynceus n. sp., holotype ovigerous female 2.0 mm (MNHN-IU-2019-2593). D, P. marina n. sp., male 1.5 mm (MNHN-IU-2019-2653). E, P. medea n. sp., paratype male 2.1 mm (MNHN-IU-2014-13795). F, P. nudus Macpherson, 2008, ovigerous female 2.4 mm (WAM C46587). G, P. nui Schnabel & Ahyong, 2019, male 6.5 mm (MNHN-IU-2019-2595). H, P. orpheus n. sp., paratype male 1.9 mm (UF33962). I, P. paula n. sp., paratype male 2.3 mm (MNHN-IU-2019-2699). J, P. penelos n. sp., paratype male 3.3 mm (UF1224). K, P. pepei n. sp., holotype male 3,2 mm (MNHN-IU-2016-486). L, P. phanus n. sp., paratype male 2.1 mm (MNHN-IU-2019-2687). Scale bars = 1 mm.

FIGURE 34. Phylladiorhynchus marina n. sp., A, C-I, holotype ovigerous female 2.0 mm (MNHN-IU-2014-13887); B, paratype male 1.5 mm (MNHN-IU-2019-2653): A, B, carapace and pleon, dorsal view. C, thoracic sternites 3 and 4. D, left cephalic region, showing antennular and antennal peduncles, ventral view. E, right Mxp3, lateral view. F, left P1, dorsal view. G, right P2, lateral view. H, right P3, lateral view. I, right P4, lateral view. Scale bars: A, B, F–I = 1.0 mm; C–E = 0.6 mm.

FIGURE 55. Colour in life, dorsal view.A, Phylladiorhynchus lini n. sp. Taiwan, holotype female 2.2 mm (NMMBCD5596). B, Phylladiorhynchus marina n. sp. Vanuatu, ovigerous female 2.0 mm (MNHN-IU-2014-13887). C, Phylladiorhynchus medea n. sp. New Caledonia, female 1.9 mm (MNHN-IU-2014-20063). D, Phylladiorhynchus orpheus n. sp. French Polynesia, ovigerous female 2.0 mm (UF9732). E, Phylladiorhynchus paula n. sp. îles de Mayotte. des Glorieuses et des Comores, female 3.3 mm (MNHN-IU-2016-7003). F, Phylladiorhynchus peneleos n. sp. French Polynesia, male 2.0 mm (UF16078). G, Phylladiorhynhus pepei n. sp. Madagascar, male 3.2 mm (MNHN-IU-2016-486). H, Phylladiorhynchus phanus n. sp. Papua New Guinea, ovigerous female 2.5 mm (MNHN-IU-2014-2893). I. Phylladiorhynchus phlias n. sp. Papua New Guinea, ovigerous female 1.3 mm (MNHN-IU-2013-703).