Phylladiorhynchus barbeae, 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 : 24-27

Phylladiorhynchus barbeae n. sp.

( Figs. 7 , 11H , 54 B–C )

Type material. Holotype. Papua New Guinea, PAPUA NIUGINI Stn PR 76, 05.0267°S, 145.7983°E, 2–15 m, 21 November 2012: M 2.5 mm (MNHN- IU-2014-13813)

Paratypes. Papua New Guinea. PAPUA NIUGINI Stn PS 07, 05.1800°S, 145.8300°E, 13 m, 8 November 2012: 1 ov. F 1.8 mm (MNHN-IU-2019-2670).— Stn PB 13, 05.2967°S, 145.7817°E, 13 m, 12 November 2012: 1 M 2.3 mm, 1 F 2.4 mm (MNHN-IU-2019-2667).— Stn PB 29, 05.3000°S, 145.7683°E, 17 m, 27 November 2012: 1 ov. F 1.6 mm (MNHN-IU-2019-2641).— Stn PB 33, 05.1517°S, 145.8283°E, 30 m, 3 December 2012: 1 F 2.4 mm (MNHN-IU-2019-2668).— Stn PS 08, 05.18395°S, 145.80718°E, 8 m, 30 December 2012: 1 M 1.4 mm (MNHN- IU-2014-13865).— Stn PB 39, 05.2650°S, 145.7850°E, 18–27 m, 6 December 2012: 2 F 2.1–2.3 mm, 1 parasitized (MNHN-IU-2019-2638) .

New Caledonia, Touho. 20.6101°S, 165.2242°E, 5–7 m, September 1993: 1 M 3.1 mm, 1 ov. F 1.7 mm (MNHN- IU-2014-13861) .

Vanuatu. SANTO Stn ZR 12, 15.6117°S, 167.0333°E, 2–30 m, 5 October 2006: 1 M 2.0 mm (MNHN-IU-2014- 13808), 1 M 2.2 mm (MNHN-IU-2019-2643) .

Other material. Papua New Guinea. KAVIENG Stn KB 16, 02.5767°S, 150.7717°E, 13–14 m, 7 June 2014: 1 M parasitized 1.8 mm ( MNHN-IU2014-13619 ).— Stn KB 20, 02.7533°S, 150.6950°E, 8 m, 9 June 2014: 1 ov. F 2.3 mm (MNHN-IU-2014-2311) .

Vanuatu. SANTO Stn FB 43, 15.4733°S, 167.2483°E, 19 m, 30 September 2006: 1 M 2.1 mm (MNHN-IU- 2019-2642).— Stn FB 68, 15.5900°S, 166.9950°E, 11 m, 11 October 2006: 1 M 2.5 mm (MNHN-IU-2014-13875).— Stn FB 72, 15.6017°S, 166.9750°E, 16 m, 12 October 2006, 1 M 1.6 mm ( MNHN-IU2014-13810 ).— Stn DB 20, 15.5083°S, 167.0233°E, 20–25 m, 15 September 2006: 2 M 1.3–2.0 mm (MNHN- IU-2019-2630) .

New Caledonia. Lagon Est. Stn 0607, 22.2017°S, 167.0417°E, 48–54 m, 5 August 1986: 1 ov. F 2.8 mm (MNHN-IU-2014-13740) .

Etymology. Named after Any Barbé, mother of one of the authors, for her unremitting support.

Description. Carapace: as long as or slightly longer than broad; transverse ridges with dense short setae. Gastric region slightly convex, with 4 transverse ridges: epigastric ridge distinct with 2 median spines; anterior protogastric ridge not medially interrupted, nearly extending laterally to carapace margin, sometimes followed by a few short scales; 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 a short median scale. Mid-transverse ridge not interrupted, medially depressed, cervical groove indistinct, followed by 2–3 not interrupted or minutely interrupted ridges, interspersed with 2 short lateral ridge and sometimes few, short scattered scales. Lateral margins nearly straight or slightly convex, with 4 distinct spines: first anterolateral spine well-developed, reaching anteriorly to level of lateral orbital spine, hepatic margin unarmed; anterolateral spine followed by 3 branchial spines (2 anterior and 1 posterior). Rostrum leaf-like, horizontal, dorsally flattened, [1.2]1.1–1.5 × as long as broad, length [0.3]–0.4 and breadth [0.2]–0.3 that of carapace; lateral margins serrated and convex, with well-developed supraocular basal spines, subapical spines absent. Pterygostomian flap ending in blunt tooth, upper margin smooth.

Thoracic sternum: As wide as long. Sternite 3 moderately broad, [1.8]–2.0 × as wide as long, anterior margin serrated and slightly convex or straight. Sternite 4 widely contiguous to sternite 3; anterolaterally serrated, surface depressed in midline, smooth; greatest width 3.3–[3.4] × that of sternite 3, 2.5–[2.6] × 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–[1.0] × broader than long, peduncle distally setose, not distinctly expanded proximally; maximum corneal diameter 0.7 × 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, distally falling well short of lateralmost antennular spine. Article 2 with well-developed distomesial and distolateral spines. Article 3 often with distomesial spine. Article 4 unarmed.

Mxp3: 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.

P1 (lost in holotype): Slender, 2.8–3.9 (males), 2.6–2.7 (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 0.9–1.4 length of carapace, 1.5–1.7 × as long as carpus. Carpus 3.0–3.4 × as long as wide. Palm 1.1 × carpus length, 2.9–3.0 × as long as broad. Fingers 0.6–0.7 × palm length; fixed finger unarmed; movable finger with a basal spine.

P2–4 (P3 lost in holotype): Slender, densely setose and spinose. Meri successively shorter posteriorly: P3 merus 0.6 × length of P2 merus, P4 merus 0.9 × length of P3 merus. P2 merus, 0.7–[0.8] × carapace length, [4.0]3.9–4.2 × as long as broad, [1.0]1.1 × as long as P2 propodus; P3 merus 4.2 × as long as broad, 1–1.1 × as long as P3 propodus; P4 merus 4.2–4.7 [4.5] × 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 P2–4, P4 lateral surface with median row of 2 spines. Carpi with 1–3 minute spines on extensor margin on P2–3, unarmed on P4; distal spine prominent on P2–3, smaller on P4; row of small granules below extensor margin on lateral surface of P2–4; flexor margin unarmed. Propodi slender, [5.5–6.5]5.2– 7.2 × as long as broad; extensor margin irregular, armed with 1–4 spines on proximal half; flexor margin with 3–4 slender movable spines in addition to distal pair. Dactyli 0.6 × length of propodi, ending in incurved, strong, sharp spine; flexor margin with 5–6 movable spines.

Eggs: Ov. F carried approximately 10– 20 eggs of 0.3–0.5 mm diameter.

Live colour. Carapace and pleon with reddish-brownish or orange patches. P1 whitish, covered by some reddish-brownish spots basally. P2–4 light whitish with reddish-brownish stripes.

Genetic data. COI and 16S, Table 1.

Distribution. Papua New Guinea, Vanuatu, New Caledonia from 2 to 54 m.

Remarks. Phylladiorhynchus barbeae belongs to the group of species having 2 median epigastric spines, the hepatic margin unarmed and 2 spines on the anterior branchial margin. The specimens range from 1.4 to 3.1 mm postorbital carapace length. The closest species is P. pepei from Madagascar (see the differences under the Remarks of this species). The four sequences of P. barbeae from New Caledonia, Papua New Guinea and Vanuatu diverged 0.2% for COI and 0% for 16S.

Figures

FIGURE 7. Phylladiorhynchus barbeae n. sp., A–D, G-I, holotype male 2.5 mm (MNHN-IU-2014-13813); E-F, paratype male 3.1 mm (MNHN-IU-13861): 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, merus and carpus, dorsal view. F, left P1, propodus and dactylus, dorsal view right. G, right P2, lateral view. H, right P4, lateral view. I, dactylus of right P2, lateral view. Scale bar: A, E–H = 1.0 mm; B–D, I = 0.6 mm.

FIGURE 11. Rostrum, dorsal view. A, Phylladiorhynchus acastus n. sp., paratype male 2.6 mm (MNHN-IU-2017-2646). B, P. amphion n. sp., holotype male 2.4 mm (WAM C55691). C, P. amphion n. sp., paratype female 2.6 mm (WAM C53887). D, P. argus n. sp., paratype ovigerous female 3.5 mm (MNHN-IU-2014-23836). E, P. asclepius n. sp., paratype ovigerous female 2.1 mm (UF22401). F, P. australis Schnabel & Ahyong, 2019, female 4.0 mm (MNHN-IU-2019-2596). G, P. bahamut n. sp., holotype male 2.5 mm (UF40205). H, P. barbeae n. sp., paratype male 2.2 mm (MNHN-IU-2019-2643). I, P. boucheti n. sp., paratype ovigerous female 2.5 mm (MNHN-IU-2017-3830). J, P. butes n. sp., paratype female 2.1 mm (MNHN-IU-2016-449). K, P. cepheus n. sp., paratype male 2.4 mm (MNHN-IU-2014-13858). L, P. eneus n. sp., paratype male 2.1 mm (MNHN-IU- 2014-13801). Scale bars = 1 mm.

FIGURE 54. Colour in life, dorsal view. A. Phylladiorhynchus acastus n. sp. Papua New Guinea, male 2.5 mm (MNHN-IU- 2014-10017). B, Phylladiorhynhus barbeae n. sp. Papua New Guinea, paratype male 1.6 mm (MNHN-IU-2014-13810). C, Phylladiorhynhus barbeae n. sp. Papua New Guinea, male 2.5 mm (MNHN-IU-2014-13813). D, Phylladiorhynchus gustavi n. sp. French Polynesia, male 2.3 mm (UF16338). E, Phylladiorhynchus janiqueae n. sp. Walter shoal, male 1.8 mm (MNHN-IU- 2014-13840). F, Phylladiorhynchus jeffkinchi n. sp. Papua New Guinea, ovigerous female 2.2 mm (MNHN-IU-2014-2176). G, Phylladiorhynchus joannotae n. sp. French Polynesia, ovigerous female 2.2 mm (UF15544). H, Phylladiorhynchus joannotae n. sp. New Caledonia, female 1.0 mm (MNHN-IU-2014-20147). I, Phylladiorhynchus koumac n. sp. New Caledonia, male 1.5 mm (MNHN-IU-2014-20121).