Phylladiorhynchus pepei, 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 : 105-107

Phylladiorhynchus pepei n. sp.

( Figs. 33K , 40 , 55G )

Type material. Holotype. Madagascar. ATIMO VATAE Stn TB 02, 25.0216°S, 47.0083°E, 18 m, 1 May 2010: M 3.2 mm (MNHN-IU-2016-486).

Paratypes. Madagascar. ATIMO VATAE Stn TP02, 25.0250°S, 47.0233°E, 25–30 m, 29 April 2010: 1 ov. F 2.7 mm ( MNHN-IU2010-2730 ) .— Stn TB02-TB03, 25.0216°S, 47.0083°E, 18 m, 1 May 2010: 2 M 2.5–2.6 mm ( MNHN-IU2016-463 ) .— Stn TB02, 25.0216°S, 47.0083°E, 18 m, 1 May 2010: 1 ov. F 2.5 mm ( MNHN-IU2016- 461 ) .— Stn TB03, 25.0216°S, 47.0083°E, 18 m, 1 May 2010: 2 ov. F 2.8–3.2 mm ( MNHN-IU2016-465 ) .

Other material. Madagascar. ATIMO VATAE Stn TB 05, 25.0366°S, 47.0066°E, 23 m, 1 May 2010: 2 ov. F 2.7–2.9 mm, 2 F 2.5–2.6 mm ( MNHN-IU2010-2742 ) .

Etymology. Named after biologist Pepe Fernández, from the Museo Nacional de Ciencias Naturales, Madrid, and especially interested in registering new species; in gratitude for his enthusiasm and support.

Description. Carapace: As long as or slightly longer than broad, transverse ridges with dense short setae and few scattered long and thick iridescent setae. Gastric region slightly convex with 4 transverse ridges: epigastric ridge distinct with 2 median spines, often followed by short scales; anterior protogastric ridge not medially interrupted, nearly extending laterally to carapace margin, often followed by uninterrupted (in large specimens) or scale-like posterior protogastric 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 short scales.Mid-transverse ridge not interrupted, medially depressed, preceeded by a shallow or indistinct cervical groove, followed by 2 not interrupted or minutely interrupted ridges, interspersed with 2 short lateral ridges and sometimes few, short scattered scales. Lateral margins slightly convex, with 4 distinct spines: first anterolateral spine welldeveloped, reaching anteriorly to level of lateral orbital spine, hepatic margin unarmed; anterolateral spine followed by 3–4 branchial spines (2 anterior and 1–2 posterior). Rostrum leaf-like, horizontal, dorsally flattened, 1.3–[1.5] × as long as broad, length 0.3–[0.4] and breadth [0.2]–0.3 that of carapace; lateral margins smooth and convex, with well-developed supraocular spines, subapical spines absent or obsolescent. Pterygostomian flap ending in acute tooth, upper margin smooth.

Thoracic sternum: As wide as long. Sternite 3 moderately broad, [1.8]1.5–2.0 × as wide as long, anterior margin convex, anterolaterally rounded. Sternite 4 widely contiguous to sternite 3, surface depressed in midline, smooth; greatest width [2.8]–3.0 × that of sternite 3, [2.8]–3.0 × as wide as long.

Pleon: Elevated ridges with short setae and a few scattered long setae. Tergite 2 with anterior and posterior transverse elevated ridges; tergites 3–4 with anterior transverse ridge; tergites 5–6 smooth.

Eye: Eyestalk length about 0.9 × broader than long, peduncle distally setose, not distinctly expanded proximally; maximum corneal diameter 0.7–[0.9] × rostrum width, as wide as eyestalk.

Antennule: Article 1 slightly longer than wide, with 5 distal spines: distomesial spine well-developed; proximal lateral spine small, always present.

Antenna: Article 1 with prominent mesial process nearly reaching end of lateralmost antennular spine. Article 2 with well-developed distomesial and distolateral spines. Article 3 and 4 unarmed.

Mxp3: Ischium with distinct distal spines on flexor and extensor margins. Merus [0.6]–0.6 × length of ischium, with well-developed distal spine on extensor and flexor margins.

P1: 2.9–[3.3] (males), 2.2–2.8 (females) × carapace length; subcylindrical, spiny and with long stiff setae and dense thick and plumose setae; merus, carpus and palm with spines along mesial, dorsal and lateral surfaces, distal and mesial spines usually stronger than others. Merus 1.1–[1.3] length of carapace, [1.9]1.6–2.2 × as long as carpus. Carpus [2.6]1.9–2.7 × as long as wide. Palm 0.9–[1.2] × carpus length, 1.5–[2.3] × as long as broad. Fingers [0.7]–1.0 × palm length; fixed finger unarmed; movable finger with a basal spine.

P2–4: Moderately stout, densely setose and spinose. Meri successively shorter posteriorly: P3 merus 0.6 × length of P2 merus, P4 merus 0.8–0.9 × length of P3 merus. P2 merus, 1.8–[2.1] × carapace length, 3.8–[5.0] × as long as broad, [1.2]–1.4 × as long as P2 propodus; P3 merus [3.9]3.7–4.0 × as long as broad, 0.9–[1.1] × as long as P3 propodus; P4 merus 4 × as long as broad, 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 P2–4, P4 lateral surface with median row of 2 spines. Carpi with 1–4 minute spines on extensor margin on P2–3, unarmed on P4; distal spine prominent on P2–3, smaller on P4; row of small spines below extensor margin on lateral surface of P2–3; flexor margin unarmed. Propodi moderately stout, [5.0–5.6]4.0–5.8 × as long as broad; extensor margin irregular, armed with 3 spines on proximal half; flexor margin with 3–4 slender movable spines in addition to distal pair. Dactyli [0.5–0.6]0.5–0.7 × length of propodi, ending in incurved, strong, sharp spine; flexor margin with 5–6 movable spines.

Eggs: Ov. F carried approximately 20– 30 eggs of 0.3–0.6 mm diameter.

Live colour. Body green-orange, with red and orange spots and patches. P1 green, tip of fingers dark orangereddish. P2–4 light green-orange, with dark green-brownish bands.

Genetic data. COI and 16S, Table 1.

Distribution. Madagascar, between 18 and 30 m.

Remarks. Phylladiorhynchus pepei belongs to the group of species having 2 median epigastric spines, the hepatic margin unarmed and 2 spines on the anterior branchial margin. This species is easily characterized by the absence of subapical spines. The new species closely resembles P. barbeae , from Papua New Guinea, Vanuatu and New Caledonia. However, both species can be distinguished on the basis of the following characters:

- The anterior margin of thoracic sternite 3 is straight or slightly convex, and produced anterolaterally in P. barbeae , whereas this margin is medially produced, and anterolaterally rounded in P. pepei .

- Antennal article 3 is often armed with a distomesial spine in P. barbeae , whereas this article is unarmed in P. pepei .

- The P2–4 propodi are slender in P. barbeae (5–7 × as long as wide), whereas they are stout (<5.8 × as long as wide) in P. pepei .

- The colour pattern of the carapace and pleon are whitish, with reddish patches, in P. barbeae , whereas the colour pattern is green or light orange, with no reddish patches, in P. pepei .

The genetic divergences between P. pepei and P. barbeae were 7% (COI) and 3% (16S). The two sequences of P. pepei from Madagascar were divergent by 0.6% for 16S. The specimens of P. pepei range in size range from 2.5 to 3.2 mm postorbital carapace length.

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 40. Phylladiorhynchus pepei n. sp., A–D, G–H, holotype male 3.2 mm (MNHN-IU-2016-486): A, carapace and pleon, dorsal view. B, thoracic sternites 3 and 4. C, left cephalic region, showing antennular and antennal peduncles, ventral view. D, right Mxp3, lateral view. E, left P1, dorsal view. F, left P2, lateral view. G, left P3, lateral view. H, dactylus of left P2, lateral view. Scale bars: 1.0 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).