Phylladiorhynchus joannotae, 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 : 64-67

Phylladiorhynchus joannotae n. sp.

( Figs. 21K , 24 , 54G–H )

Type material: Holotype. Vanuatu, SANTO Stn DB 33, 15.5783°S, 167.2300°E, 14–25 m, 18 September 2006: 1 ov. F 2.1 mm (MNHN-IU-2014-13805).

Paratypes. Vanuatu. SANTO Stn ZB 9, 15.6766°S, 167.0850°E, 5–7 m, 02 October 2006: 1 ov. F 1.7 mm (MNHN-IU-2019-2627).— Stn DB 86, 15.6416°S, 167.2516°E, 13 m, 04 October 2006: 1 ov. F 2.3 mm (MNHN- IU-2014-13809).— Stn DB 1, 15.5516°S, 167.2966°E, 15–25 m, 10 September 2006: 1 M 1.8 mm (MNHN-IU- 2019-2628).— Stn FB 72, 15.6016°S, 166.9750°E, 16 m, 12 October 2006: 1 M 2.2 mm, 1 postlarvae (MNHN- IU-2014-13877).— Stn DB 29, 15.6483°S, 167.0850°E, 15 m, 17 September 2006: 1 M 1.9 mm, 1 F 1.7 mm (MNHN-IU-2014-13869).— Stn ZB 6, 15.6133°S, 167.0216°E, 30 m, 28 September 2006: 1 F 1.7 mm (MNHN-IU- 2014-13871) .

New Caledonia Koumac 2.3 Stn KL 39, 20.7511°S, 164.23276°E, 26 m, 10 November 2019: 1 M 2.1 mm, 2 ov. F 1.9–2.5 mm, 3 F 1.7–2.0 mm (MNHN-IU-2014-20055) .

Other material. American Samoa. Olosega Island. OLO-057, 14.18140174°S, 169.6267462°W, 14 m, 14 March 2015: 1 ov. F 2.0 mm ( UF54536 ) .— OLO-211, 14.18140174°S, 169.6267462°W, 14 m, 14 March 2015: 1 M 2.2 mm ( UF54537 ) .

French Polynesia. Society Islands , Moorea Island, Fore reef NE of Tareu Pass, outer reef slope, rubble , 17.4803°S, 149.8539°W, 35–37 m, 2 August 2006: 1 broken ( UF10072 ) .— 17.4826°S, 149.8962°W, 14 October 2008: 1 ov. F 2.2 mm ( UF15544 ) .— 17.5145°S, 149.7616°W, 22 m, 23 October 2008: 1 ov. F 1.8 mm ( UF16051 ) .— 17.5303°S, 149.7621°W, 15–32 m, 27 October 2008: 1 ov. F 1.9 mm ( UF16169 ) .

Northern Mariana Islands. Saipan Island. Stn SAI-441, 15.0978°N, 145.7434°E, 17 m, 11 April 2014, 1 M 1.6 mm, 1 ov. F 2.0 mm ( UF54538 ) .— Stn SAI-477, 15.0978°N, 145.7434°E, 17 m, 11 April 2014: 1 M 2.0 mm ( UF54540 ) .— Stn SAI-584, 15.0978°N, 145.7434°E, 17 m, 11 April 2014: 1 M 2.0 mm ( UF54540 ) .— Pagan Island . Stn PAG-694, 18.0706862°N, 145.7137933°E, 37 m, 20 April 2014: 1 ov. F 2.2 mm, 1 F 1.9 mm ( UF54533 ) .— Stn PAG-809, 18.0707°N, 145.7138°E, 37 m, 20 April 2014: 1 M 1.4 mm ( UF54534 ) .

Marshall Islands. Wake Island. Stn WAK-115, 19.2918°N, 166.6073°E, 14 m, 17 March 2014: 1 F 1.7 mm ( UF54535 ) .

Chesterfield Islands , Ebisco, Stn DW 2569, 20.3963°S, 158.6699°E, 50 m, 14 October 2005: 1 ov. F 1.7 mm (MNHN-IU-2014-13912) .

New Caledonia. New Caledonia, Lagon Est , Stn 735, 22.0850°S, 166.9533°E, 15–34 m, August 1986: 1 M 2.5 mm (MNHN-IU-2019-2620).—Touho Dive, 7 September 1993: 1 M 1.7 mm, 2 ov. F 2.0, 2.1 mm, 1 F 2.1 mm (MNHN-IU-2019-2614).—Touho, 6 September 1993: 2 M 1.5, 1.6 mm, 2 F 1.7, 1.8 mm (MNHN-IU-2016- 498).—Exp. Mont. Komac, 12 m, 7 October 1993: 1 M parasitized 2.5 mm (MNHN-IU-2019-2634).—LIFOU Stn 1430, 20.7916°S, 167.1183°E, 20–25 m, 9 November 2000: 1 ov. F 2.6 mm (MNHN-IU-2019-2622).—Stn 1452, 20.9100°S, 167.0350°E, 2–25 m, 20 November 2000: 1 M 2.2 mm, 1 ov. F 2.0 mm (MNHN-IU-2019- 2599).—Stn 1455, 20.9466°S, 167.0450°E, 15–20 m, 25 November 2000: 1 M 2.0 mm, 2 ov. F 2.1–2.2 mm (IU- 2019-2626).—Koumac 2.3 Stn KB 612, 20.6695°S, 164.18941°E, 13 m, 01 November 2019: 1 M 1.5 mm, 1 F parasitized 1.6 mm, 1 postlarvae 1.0 mm (MNHN-2019-2580) 1 broken (MNHN-IU-2014-3426).— Stn KB 613, 20.6682°S, 164.18962°E, 15 m, 01 November 2019: 1 ov. F 1.5 mm (MNHN-IU-2019-1556), 1 M 1.3 mm, 5 ov. F 1.4–1.9 mm, 2 F 1.1–2.0 mm (MNHN-IU-2019-1573).— Stn KB 615, 20.6943°S, 164.24786°E, 13 m, 02 November 2019: 1 ov. F 1.5 mm (MNHN-IU-2019-1560), 4 F 1.5–1.8 mm (MNHN-IU-2014-20198).— Stn KB 619, 20.5135°S, 164.03151°E, 12 m, 03 November 2019: 2 M 1.8–1.9 mm (MNHN-IU-2019-1562), 1 F 1.8 mm (IU- 2019-5518).— Stn KB 622, 20.75144°S, 164.23203°E, 19 m, 04 November 2019: 2 M 1.4–1.5 mm, 2 F parasitized 1.5–1.6 mm (MNHN-IU-2019-1572).— Stn KB 623, 20.7518°S, 164.2340°E, 12 m, 05 November 2019: 2 M 1.5– 1.6 mm, 3 F 1.1–1.8 mm, 1 postlarvae 1.0 mm (MNHN-IU-2019-3418).— Stn KB 624, 20.62347°S, 164.14964°E, 3 m, 05 November 2019: 1 M 1.3 mm (MNHN-IU-2019-3420), 1 M 1.4 mm (MNHN-IU-2019-3428).— Stn KB 631, 20.52698°S, 164.02615°E, 3 m, 08 November 2019: 1 M 1.8 mm, 1 postlarvae 1.0 mm (MNHN-IU-2014-20079).— Stn KB 633, 20.59318°S, 164.25161°E, 41 m, 10 November 2019: 2 M 1.0– 1.2 mm, 3 ov. F 1.4–1.5 mm, 1 F 1.2 mm (MNHN-IU-2014-20048).— Stn KB 636, 20.63948°S, 164.18293°E, 3 m, 10 November 2019: 1 F 1.9 mm (MNHN-IU-2014-20062), 1 M 1.8 mm, 1 ov. F 2.1 mm, 1 F parasitized 1.7 mm (MNHN-IU-2014-20064), 1 M 1.6 mm (MNHN-IU-2014-20066).— Stn KL 39, 20.7511°S, 164.23276°E, 26 m, 10 November 2019: 4 M 1.4–1.8 mm, 4 F parasitized 1.5–1.8 mm (MNHN-IU-2014-20172), 1 F 1.3 mm (MNHN-IU-2014-20046), 1 ov. F 2.3 mm (MNHN-IU-2014-20056).— Stn KL 40, 20.75156°S, 164.2343°E, 52 m, 10 November 2019: 1 ov. F 2.2 mm (MNHN-IU-2014-20083).— Stn KL 03, 20.67485°S, 164.214266°E, 50 m, 11 November 2019: 1 F 1.8 mm (MNHN- IU-2014-20069).— Stn KB 638, 20.594533°S, 164.10925°E, 4 m, 13 November 2019: 1 M 2.0 mm, 1 ov. F 2.6 mm, 1 F parasitized 2.0 mm (MNHN-IU-2014-20119).— Stn KB 639, 20.7511°S, 164.23245°E, 22 m, 13 November 2019: 1 ov. F 1.7 mm, 3 F 1.6–2.2 mm (MNHN-IU-2014-20196).— Stn KB 640, 20.72511°S, 164.26738°E, 6 m, 13 November 2019: 1 M parasitized 2.0 mm (MNHN-IU-2014-20111), 2 M 1.5–2.0 mm, 1 ov. F 2.4 mm (MNHN- IU-2014-20112).— Stn KD 558, 20.72775°S, 164.26546°E, 6 m, 13 November 2019: 1 F parasitized 1.9 mm (MNHN-IU-2014-20088).— Stn KB 641, 20.7988°S, 164.27253°E, 36 m, 14 November 2019: 1 broken (MNHN- IU-2014-20102).— Stn KB 643, 20.61416°S, 164.13703°E, 3 m, 14 November 2019: 2 M 1.4–2.5 mm, 6 ov. F 2.4–2.6 mm (MNHN-IU-2014-20096), 1 M 2.2 mm (MNHN-IU-2019-5320), 1 ov. F 2.1 mm (MNHN-IU-2019- 5319).— Stn KB 645, 20.67573°S, 164.2171°E, 16 m, 15 November 2019: 1 F 1.3 mm (MNHN-IU-2014-20115), 2 M 1.2–1.3 mm, 5 F 1.0– 1.2 mm (MNHN-IU-2014-20125).— Stn KB 646, 20.644983°S, 164.24386°E, 12 m, 15 November 2019: 1 F parasitized 2.1 mm (MNHN-IU-2014-20114), 1 M 1.7 mm, 1 postlarvae 0.9 mm (MNHN-IU- 2014-20118).— Stn KB 647, 20.664116°S, 164.189983°E, 38 m, 16 November 2019: 1 ov. F 1.6 mm, 3 F 1.0–1.9

mm (MNHN-IU-2014-20139).—Stn KL27, 20.7878°S, 164.27191°E, 102 m, 16 November 2019: 1 juv. 1.0 mm (MNHN-IU-2014-20129).—Stn KL37, 20.8319°S, 164.27818°E, 81 m, 16 November 2019: 1 M 1.1 mm (MNHN- IU-2014-20132).—Stn KB649, 20.80583°S, 164.26916°E, 42 m, 18 November 2019: 5 F 1.7–1.9 mm, 5 postlarvae 0.9–1.0 mm (MNHN-IU-2014-20154).—Stn KB651, 20.83145°S, 164.280556°E, 12 m, 18 November 2019: 1 postlarvae 1.1 mm (MNHN-IU-2014-20143), 1 F 1.0 mm (MNHN-IU-2014-20147).—Stn KB651, 20.83145°S, 164.280556°E, 12 m, 18 November 2019: 1 postlarvae 1.1 mm (MNHN-IU-2014-20148), 1 F 1.8 mm (MNHN- IU-2014-20144).—Stn KB654, 20.44587°S, 163.97254°E, 15 m, 19 November 2019: 7 F parasitized 1.1–2.1 mm (MNHN-IU-2014-20164).—Stn KB655, 20.68517°S, 164.27078°E, 6 m, 20 November 2019: 1 M 1.9 mm, 1 F parasitized 2.2 mm (MNHN-IU-2014-20193).—Stn KB659, 20.66049°S, 164.26852°E, 15 m, 21 November 2019: 1 M 1.9 mm (MNHN-IU-2014-20176).—Stn KB664, 20.66925°S, 164.230805°E, 3 m, 23 November 2019: 1 F parasitized 1.8 mm (MNHN-IU-2014-20184).—Stn ARMS 2B, November 2019: 1 M 1.7 mm (MNHN-IU-2014- 20074).—Stn ARMS 8B, November 2019: 1 M 1.8 mm, 2 ov. F 2.2.– 2.3 mm (MNHN-IU-2014-20162).

Etymology. The new species is named after Pascale Joannot, Head of the MNHN Expeditions programme, who has been instrumental in raising support for the Our Planet Reviewed New Caledonia expeditions.

Description. Carapace: as long as or slightly broader than long, sexually dimorphic (wider on females) 0.9–1.0 (males), [0.8]–0.9 (females); transverse ridges with dense short setae and few scattered thick and iridescent setae. Gastric region slightly convex with 4 transverse ridges: epigastric ridge distinct with 2 median spines and some lateral short scales, often followed by small scattered scales; anterior protogastric ridge not medially interrupted, nearly extending laterally to carapace margin, often followed by small scattered scales; anterior mesogastric ridge not medially interrupted, continuing to first branchial spine; anterior metagastric not medially interrupted, sometimes followed by short scattered scales on posterior metagastric region. Mid-transverse ridge not interrupted, medially slightly depressed, cervical groove indistinct, followed by 2 not interrupted or minutely interrupted ridges, interspersed with 2 short lateral ridges and few short scales. Lateral margins convex, with 6 distinct spines: first anterolateral spine well-developed, reaching anteriorly to level of lateral orbital spine, second spine (hepatic) welldeveloped, slightly dorsomesially from lateral margin, and followed by 4–5 branchial spines (3 anterior and 1–2 posterior). Rostrum leaf-like, horizontal, dorsally flattish or slightly concave, sexually dimorphic (shorter and wider on females) 1.5–1.8 (males), [1.1]–1.6 × 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 basal spines and small subapical spines. Pterygostomian flap ending in blunt tooth, upper margin smooth.

Thoracic sternum: Slightly wider than long. Sternite 3 broad, [2.8]–3.0 × as wide as long, anterior margin convex, anterolaterally rounded. Sternite 4 widely contiguous to sternite 3; anterolaterally rounded, surface depressed in midline, smooth; greatest width [2.9]–3.0 × that of sternite 3, 3.0–[3.5] × as wide as long.

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

Eye: Eyestalk length about 0.9–[1.1] × broader than long, peduncle distally setose, not distinctly expanded proximally; cornea expanded distally, maximum corneal diameter [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, distally falling well short of lateralmost antennular spine. Article 2 with well-developed distomesial and distolateral spines. Article 3 with distomesial spine. Article 4 unarmed.

Mxp3: Ischium with distinct distal spines on flexor and extensor margins. Merus 0.8 × length of ischium, with well-developed distal spine on extensor and flexor margins.

P1: [3.3]3.0–3.5 (males), 1.8–2.2 (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 0.7–[1.2] length of carapace, [1.6]–2.2 × as long as carpus. Carpus 1.5–[2.0] × as long as wide. Palm 1.2 × carpus length, 1.9–[2.2] × as long as broad. Fingers [0.7]–1.0 × palm length; fixed finger unarmed; movable finger with 1–2 basal spines.

P2–4: Setose and spinose. Meri successively shorter posteriorly: P3 merus 0.9 × length of P2 merus, P4 merus 0.8–0.9 × length of P3 merus. P2 merus, 0.5 × carapace length, 3.5–3.6 × as long as broad, 1.0–1.1 × as long as P2 propodus; P3 merus 3.0–4.3 × as long as broad, 1.1–1.3 × as long as P3 propodus; P4 merus 2.6–3.0 × 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 P2–3, absent on P4. Carpi with 1–3 spines on extensor margin on P2–3, unarmed on P4; distal spine prominent on P2–3, absent on P4; granules below extensor margin on lateral surface of P2–4; flexor margin unarmed. Propodi stout, [4.0–5.0]3.7–4.8 × as long as broad; extensor margin irregular; flexor margin with 3 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 cuticular spines at basis of 5–6 movable spines.

Eggs: Ov. F carried approximately 20– 25 eggs of 0.3 mm diameter.

Live colour. Variable; base colour white or pale beige. Carapace with fine red to brown markings ( Fig 54H ) or with dense patches of red to dark brown chromatophores ( Fig 54G ). Rostrum with dark transverse bar at least across base. P1–4 with dark brown bars and scattered white spots.

Genetic data. COI and 16S, Table 1.

Distribution. French Polynesia, Vanuatu, Papua New Guinea, Guam Island, Northern Mariana Islands, American Samoa and New Caledonia, from 5 to 102 m.

Remarks. Phylladiorhynchus joannotae belongs to the group of species having 2 epigastric spines, 1 hepatic spine, 3 spines on the anterior branchial margin of the carapace and cuticular spines along the flexor margin of the P2–4 dactyli. The morphologically and genetically closest species is P. amphion , from Western Australia. However, these species can be distinguished in basis of the following characters:

- The metagastric ridge is usually interrupted in P. amphion , whereas it is not medially interrupted in P. joannotae .

- P. joannotae has iridescent setae in the carapace and pleon, whereas these setae are absent in P. amphion .

The specimens of P. joannotae range from 1.0 to 2.6 mm postorbital carapace length. P. joannotae showed divergences of 9% (COI) and 6% (16S) with the closest relative ( P. amphion ). The 11 sequences of P. joannotae from New Caledonia and Vanuatu diverged 0–2% for COI and 0–1% for 16S.

Figures

FIGURE 21. Rostrum, dorsal view. A, Phylladiorhynchus euryalus n. sp., paratype male 1.8 mm (UF34732). B, P. gustavi n. sp., paratype male 1.7 mm (UF9756). C, P. heptacanthus n. sp., holotype female 2.1 mm (MNHN-IU-2017-2534). D, P. hylas n. sp., paratype female 1.6 mm (MNHN-IU-2016-495). E, P. integrirostris (Dana, 1852), male 1.6 mm (UF15285). F, P. integrus (Benedict, 1902), ovigerous female 3.2 mm (MNHN-IU-2014-13853). G, P. iphiclus n. sp., holotype ovigerous female 2.3 mm (MNHN-IU-2019-2662). H, P. janiqueae n. sp., paratype male 1.8 mm (MNHN-IU-2016-482). I, P. jeffkinchi n. sp., paratype male 2.7 mm (MNHN-IU-2014-13565). J, P. joannotae n. sp., paratype male 2.1 mm (MNHN-IU-2014-20055). K, P. joannotae n. sp., holotype ovigerous female 2.1 mm (MNHN-IU-2014-13805). L, P. koumac n. sp., paratype male 1.5 mm (MNHN-IU- 2014-20121). Scale bars: 1 mm.

FIGURE 24. Phylladiorhynchus joannotae n. sp., A, C–E, H-I, holotype ovigerous female 2.1 mm (MNHN-IU-2014-13805); B, F, paratype male 2.1 mm (MNHN-IU-2014-20055): 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, left P3, lateral view. H, left P4, lateral view. I, dactylus of left P3, lateral view. Scale bars = 1.0 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).