Galathea paulayi, Macpherson, Enrique & Robainas-Barcia, Aymee, 2015

Macpherson, Enrique & Robainas-Barcia, Aymee, 2015, Species of the genus Galathea Fabricius, 1793 (Crustacea, Decapoda, Galatheidae) from the Indian and Pacific Oceans, with descriptions of 92 new species, Zootaxa 3913 (1), pp. 1-335 : 219-222

Galathea paulayi n. sp.

( Figs 79 , 118 H)

Galathea sp.— Poore et al., 2011: 334, pl. 12F (color photo, Moorea).

Material examined. Holotype: French Polynesia. Moorea Island, 17.5145°S, 149.7616°W, 20 m, 23 October 2008: M 5.3 mm (UF16039).

Paratypes: French Polynesia. Society Islands. Moorea Island, NE of Tareu Pass, 17.4836°S, 149.8581°W, 22 m, 24 July 2006: 1 ov. F 4.6 mm (UF9750).—Moorea Island, ca. 1 km W of Avaoa Pass, 17°4758°S, 149.8322°W, 20 m, 25 July 2006: 1 M 5.3 mm (UF9689).—Moorea Island, fore reef between Cook's and Opunohu Bay, 17.4747°S, 149.8392°W, 18 m, 28 July 2006: 1 ov. F 4.7 mm (UF10163).—Moorea Island, Barrier reef, 17.4768°S, 149.8327°W, no depth, 5 August 2006: 3 ov. F 4.2–5.0 mm (UF14832).—Moorea Island, 17.4817°S, 149.8558°W, 17–18 m, 16 October 2008: 1 M 4.7 mm (UF15618), 1 M 4.5 mm (UF15641).—Moorea Island, 17.479°S, 149.7643°W, 29 m, 17 October 2008: 1 M 3.5 mm (UF15687).—Moorea Island, 17.5145°S, 149.7616°W, 20 m, 23 October 2008: 1 F 4.5 mm (UF16036), 3 M 4.9–5.2 mm, 2 ov. F 3.6–4.5 mm (UF16044).—Moorea Island, 17.4764°S, 149.8327°W, 4–7 m, 10 November 2008: 1 M 3.2 mm (UF16350), 1 M 4.3 mm (UF16400).—Moorea Island, 17.5493°S, 149.784°W, 0 m, 19 October 2008: 1 M 3.1 mm (UF15784).—Moorea Island, 17.5099°S, 149.761°W, 33 m, 26 October 2008: 2 M 4.2–6.0 mm, 2 ov. F 3.4–3.7 mm (UF36176).—Moorea Island, 17.4758°S, 149.8314°W, 11–12 m, 18 October 2009: 2 F 2.0– 2.6 mm (UF34937).—Moorea Island, 17.4756°S, 149.8425°W, 13–17 m, 5 December 2009: 1 ov. F 4.3 mm (UF24186).—Moorea Island, 17.5496°S, 149.776°W, 30–35 m, 9 December 2009: 1 ov. F 4.4 mm (UF37688).—Moorea Island, 17.5219°S, 149.7622°W, 20 m, 23 November 2010: 1 M 4.1 mm (UF29189).—Moorea Island, 17.4759°S, 149.8419°W, 11 m, 30 January 2012: 1 M 3.7 mm (UF33742).

French Polynesia, Gambier Islands. Temoe Atoll, 23.3152°S, 134.4956°W, 15.5 m, 10 February 2013: 1 ov. F 5.2 mm (UF35530), 1 ov. F 4.7 mm (UF35531), 1 F 2.7 mm (UF35532), 1 M 1.5 mm (UF35533), 1 F 1.8 mm (UF35536).

French Polynesia. Austral Islands. BENTHAUS, Stn DW1880, 27°54.8'S, 143°29.45'W, 90–94 m, 6 November 2002: 1 F 3.4 mm (MNHN-IU-2013-15817).—Stn DW1879, 27°54.8'S, 143°30.14'W, 52 m, 6 November 2002: 3 M 4.0– 4.1 mm, 4 ov. F 3.4–5.2 mm, 3 F 2.6–4.5 mm (MNHN-IU-2013-15818), 1 M 4.0 mm (MNHN-IU-2013-13923), 1 ov. F 5.0 mm (MNHN-IU-2013-15819).—Stn DW1917, 27°03,29'S, 146°03,82'W, 50–60 m, 12 November 2002: 1 M 4.4 mm (MNHN-IU-2013-8448).

French Polynesia. Austral Islands. Rapa, Stn 4, 27°34.3'S, 144°22.1'W, 18 m, 4 November 2002: 1 M 3.1 mm (MNHN-IU-2013-15816).—Stn 30, 27°38.2'S, 144°18.2'W, 16–20 m, 16/ 18 November 2002: 2 M 3.5–3.7 mm, 3 ov. F 3.8–4.7 mm, 1 F 3.5 mm (MNHN-IU-2013-15815).—Stn 32, 27°35.8'S, 144°23.0'W, 15–20 m, 18 November 2002: 6 M 3.0– 5.6 mm, 7 F 3.3–4.2 mm (MNHN-IU-2013-15814).

Kiribati. Line Islands. Fint Island, 11.4311°S, 151.8248°W, 10 m, 18 October 2013: 3 M 1.8–3.0 mm, 1 F 2.0 mm (UF38754).— 11.4311°S, 151.8248°W, 10 m, 19 October 2013: 1 M 3.2 mm (UF38473), 1 M 3.4 mm (UF39161). Milennium Island, 9.91°S, 150.21°W, 12 m, 5 November 2013: 1 M 3.2 mm (UF38705). Starbuck Island, 5.64°S, 155.88°W, 1 m, 26 October 2013: 1 M 3.6 mm, 1 F 2.5 mm (UF39147).— 5.64°S, 155.88°W, 10–12 m, 29 October 2013: 1 F 3.6 mm (UF39148).

Etymology. This species is dedicated to Gustav Paulay of the Florida Museum of Natural History, Gainesville, for his valuable contributions to benthic research.

Description. Carapace. As long as broad; anterior cervical groove indistinct; ridges with dense short setae and a few scattered moderately long non plumose setae. Eight ridges on gastric region: 2 epigastric ridges, anterior one with 2 epigastric spines, medially convex, sometimes medially interrupted, posterior ridge short and scale-like; 2 protogastric ridges, anterior one uninterrupted, with 1 parahepatic spine at each side, posterior ridge usually uninterrupted; 2 mesogastric ridges, anterior ridge uninterruptedly extending laterally to anteriormost of branchial marginal spines, posterior one short; 2 metagastric ridges, anterior ridge uninterrupted and sometimes fused with anterior branchial ridge, posterior ridge short. Mid-transverse ridge uninterrupted, preceded by shallow cervical groove, followed by 6 ridges, 3 or 4 uninterrupted ridges. Lateral margins medially convex, with 7 spines: 2 spines in front of, and 5 spines behind, indistinct anterior cervical groove; first anterolateral, well-developed, at same level of lateral limit of orbit, accompanying another spine ventral to between first and second, second spine small; 2 spines on anterior branchial region, last small, and 3 spines on posterior branchial margin, last small. External orbital limit ending in small spine; infra-orbital margin with strong spine. Rostrum broad triangular, 1.3–1.4 times as long as broad, length 0.5–0.6 that of, breadth 0.4 that of carapace; distance between distalmost lateral incisions 0.25–0.30 distance between proximalmost lateral incisions, dorsal surface nearly horizontal in lateral view, numerous setose small scales; lateral margin with 4 sharp teeth.

Pterygostomian flap rugose, with spine on anterior ridge, anterior margin ending in well-developed spine.

Sternum: Slightly briader than long, lateral limits divergent posteriorly.

Abdomen: Somites 2–4 each with 2 uninterrupted transverse ridges on tergite; somites 5 and 6 each with 2 medially interrupted ridges. Males with G1 and G2.

Eyes: Ocular peduncles 1.2 times longer than broad, maximum corneal diameter 0.6 rostrum width.

Antennule: Article 1 with 3 well-developed distal spines, distodorsal larger. Ultimate article with a few short setae not in tuft on distodorsal margin.

Antenna: Article 1 hardly visible from dorsal view, with depressed ventral distomesial process reaching distal margin of peduncle. Article 2 with distomesial spine smaller than distolateral, exceeding midlength of article 3. Articles 3 and 4 unarmed.

Mxp3: Ischium with well-developed distal spine on flexor margin; extensor margin unarmed; crista dentata with 26 or 27 denticles. Merus subequal in length to ischium, with 3 strong spines on flexor margin, proximal one located at midlength, distal one at terminal end, median spine smaller than others; extensor margin with distal spine. Carpus with distal spine on flexor margin.

P1: 1.8–3.0 times carapace length, with numerous short setae and some scattered long plumose setae on dorsal surface and along lateral and mesial margins of all articles. Merus 0.5–1.0 times carapace length, 1.3–1.9 times as long as carpus, with rows of spines, mesial and distal spines strong. Carpus 0.7–0.8 length of palm, 1.2–1.5, times longer than broad, lateral and mesial margins subparallel, dorsal surface with some spines in 2 longitudinal rows; mesial surface with row of well-developed spines; and row of small spines along lateral margin. Palm 1.3–1.5 times longer than broad, lateral and mesial margins subparallel; small spines roughly in rows on dorsal; lateral row continued on to lateral margin of fixed finger; mesial row continuing on the mesial margin of movable finger. Fingers 0.7–0.9 as long as palm, each finger distally with two rows of teeth, spooned.

P2–4: Relatively slender, somewhat compressed, moderately setose, sparsely with long setae on all articles. P2 1.7 times carapace length. Meri successively shorter posteriorly (P3 merus 0.9 length of P2 merus, P4 merus 0.8 length of P3 merus); P2 merus 0.7–0.8 carapace length, 3.5–3.9 times as long as broad, 1.5–1.6 times longer than P2 propodus; P3 merus 3.0–3.5 times as long as broad, 1.3 times length of P3 propodus; P4 merus 3.0 times as long as broad, 1.1 length of P4 propodus. Extensor margins with row of 7 or 8 proximally diminishing spines on P2–3, 6 spines on P4; lateral surface unarmed on P2–3, 1 or 2 spines on P4; flexorlateral margins with strong terminal spine and 1 or 2 additional spines (not on P4) on terminal half; flexomesial margin with terminal spine on P2–3. Carpi with 4 or 5 spines on extensor margin; lateral surface with row of 2–4 small spines or acute granules paralleling extensor row; flexor distal margins with spine. Propodi slightly shorter on P2, each 4.5–5.5 times as long as broad; extensor margin with 3 or 4 proximal spines on P2–4; flexor margin with 5 or 6 slender movable spines on P2–3, 4 on P4; 3 proximal spines on lateral side of P4. Dactyli subequal in length, 0.5 length of propodi, ending in incurved, strong, sharp spine; flexor margin with prominent triangular terminal tooth preceded by obsolescent 4 or 5 teeth.

Epipods present on P1–3, sometimes only on P1–2.

Coloration. Ground color of carapace and abdomen orange. Carapace and abdomen with some bluish flecks and spots. Rostrum orange or reddish, spines with white spots and red tips. Base color of P1–4 reddish; P1 finger tips white; P2–4 meri each with one distal white spot.

Remarks. Galathea paulayi belongs to the group of species having an uninterrupted ridge between the anteriormost branchial marginal spines, the rostrum has four lateral teeth, the carapace lateral margin having one small spine between the anterolateral spine and the anteriormost branchial marginal spine, one pair of epigastric spines, and the antennal article 3 with a distinct distomesial spine. The new species is closely related to G. guttata Osawa, 2004 from the Ryukyu and Izu Islands, Japan.

The new species is easily distinguished from G. guttata by the following characters:

- The pterygostomian flap has one facial spine on the anterior part in G. paulayi , whereas such a spine is absent in G. guttata .

- The flexor margin of the Mxp3 merus has three spines in G. paulayi , whereas there are only two spines in G. guttata . Furthermore, there is one distal spine on the flexor margin of the Mxp3 carpus in the new species, which is absent in G. guttata .

- The epipod on P3 is present in the new species, whereas it is absent on P 3 in G. guttata .

The genetic divergences between G. paulayi and other species are always higher than 9.6% (COI, the closest is G. homologa n. sp.) and 7.8% (16S rRNA, the closest is G. anouchkae n. sp.) ( Tab. 1). No genetic data are available for G. guttata .

Distribution. French Polynesia (Austral, Society and Gambier Islands), Line Islands, 0–94 m, on hard bottoms, sand, rubble, and dead corals

Figures

FIGURE 79. Galathea paulayi n. sp., holotype, male, 5.3 mm, French Polynesia (UF 16039). A, carapace and abdomen, dorsal view; B, thoracic sternites 3 and 4; C, left part of cephalothorax, ventral view, showing antennular and antennal peduncles, and anterior part of pterygostomian flap; D, ischium, merus and carpus of right Mxp 3, lateral view; E, right P 1, dorsal view; F, right P 2, lateral view; G, right P 3, lateral view; H, right P 4, lateral view. Scale: A, E – H = 1 mm; B – D = 0.5 mm.

FIGURE 118. Dorsal view. A, Galathea maculiabdominalis Baba, 1972, Vanuatu, male 2.4 mm (MNHN-IU- 2013 - 8344). B, Galathea mariae n. sp., French Polynesia, ovigerous female 3.0 mm (UF 15523). C, Galathea mauritiana Bouvier, 1914, Madagascar, female 2.5 mm (IU- 2013 - 9740). D, Galathea minima n. sp., Papua New Guinea, ovigerous female 2.8 mm (MNHN-IU- 2013 - 704). E, Galathea minima n. sp., Papua New Guinea, ovigerous female 2.5 mm (MNHN-IU- 2013 - 654). F, Galathea ohshimai Miyake & Baba, 1967, Vanuatu, male 2.2 mm (MNHN-IU- 2013 - 13881). G, Galathea parvula n. sp., holotype, ovigerous female 2.9 mm (UF 38286). H, Galathea paulayi n. sp., French Polynesia, male 4.7 mm (UF 15618). I, Galathea peitho n. sp., Papua New Guinea, male 4.0 mm (MNHN-IU- 2013 - 372).