Galathea pilosa De Man , 1888

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 : 232-235

Galathea pilosa De Man, 1888

( Figs 84 , 119 A, B)

Galathea pilosa De Man, 1888: 460 , pl. 19, figs 4, 4a ( Ambon).— Miyake & Baba, 1966a: 72, figs 11, 12 (Amami-oshima Island, intertidal).— Baba, 1977a: 245 (Obi Major).— Kamezaki et al., 1988: 98, with color fig. (Okinawa Island).—Baba et al., 2008: 75 (compilation).— Dong & Li, 2010: 16 , fig. 9 (South China Sea, 1–3 m).

? Galathea pilosa .— Edmondson, 1951: 196, fig. 7 ( Christmas Island).

Not Galathea pilosa . — Poore et al., 2011: 333, pl. 11E (color photo, Moorea) (= G. polyphemus n. sp.).

Material examined. Holotype: Indonesia. Moluccas. Ambon, July–September 1888: M 3.7 mm ( SMF 214).

Maldives Islands. Magoodhoo Island, 3.077°N, 72.969°E, 12 m, 14 May 2014: 1 M 3.6 mm, 1 ov. F 4.5 mm (UF39675).

Mariana Islands. Guam Island. Apra harbour, near Dog Leg reef, 6 m, 1 April 1998: 1 ov. F 4.2 mm (UF315).—UGML-498: 1 M 2.4 mm (UF549).

Papua New Guinea. PAPUA NIUGINI, Stn PB49, 05°06.4'S, 145°49.4'E, 6 m, 30 December 2012: 1 ov. F 4.5 mm (MNHN-IU-2013-1055).

Line Islands. Tabuaeran Atoll, W side of atoll, 10–15 m, 3.8418°N, 159.3608°W, 12 August 2005: 1 F broken (UF10847).— Palmyra Atoll, 0–15.7 m, 5.896°N, 162.1195°E, 21 August 2005: 1 F 5.2 mm (UF13796).—Starbuck Island, 5.64°S, 155.88°W, 1 m, 26 October 2013: 1 M 3.0 mm (UF39147).— 5.64°S, 155.88°W, 16 m, 26 October 2013: 2 M 2.8–3.3 mm, 6 F 3.0– 3.7 mm (UF39399).—Fint Island, 11.4311°S, 151.8248°W, 10 m, 19 October 2013: 1 M 3.0 mm (UF39190).

French Polynesia. Society Islands. Moorea Island, 12 October 2008: 1 M 4.4 mm (UF15424).

New Caledonia. Lifou Island. LIFOU, Stn 1420, 20°47.7'S, 167°09.35'E, 4–5 m, 18–19 November 2000: 2 F 3.7–4.2 mm (MNHN-IU-2013-8410).—Stn 1451, 20°47.3'S, 167°06.8'E, 10–21 m, 19 November 2000: 1 M 3.5 mm (MNHN-IU-2013-8411).

New Caledonia. Lagon East. Stn 625, 21°59.2'S, 166°53.6'E, 34–40 m, August 1986: 1 M 5.6 mm (MNHN- IU-2013-8409).

Description. Carapace: Slightly broader than long; dorsal surface nearly horizontal from anterior to posterior; transverse ridges with dense short setae, and numerous long plumose setae, some iridescent, and denser on rostrum surface; cervical groove distinct, laterally bifurcated. Gastric region with some transverse ridges: 1 epigastric ridge medially interrupted, with 4 or 5 spines; 2 protogastric ridges, anterior ridge usually uninterrupted, medially convex, with minute parahepatic spine on each side, sometimes absent, posterior ridge short, scale-like; 1 mesogastric ridge uninterrupted but not extending laterally to anteriormost of branchial marginal spines; 2 metagastric ridges, anterior ridge usually uninterrupted, not continuing laterally to anteriorbranchial ridges, posterior ridge moderately short. Hepatic region unarmed. Anterior branchial region with distinct ridges, 1 spine on each side. One post-cervical spine, usually on each side. Mid-transverse ridge uninterrupted, preceded by shallow cervical groove, usually followed by 5 ridges before posterior ridge, 2 ridges uninterrupted. Lateral margins well convex medially, with 6 or 7 spines: 2 spines in front of, and 4 or 5 spines behind, anterior cervical groove; first anterolateral, well-developed, at same level of lateral limit of orbit, second, small, without spine ventral to between first and second; 2 or 3 spines on anterior branchial region, and 1 or 2 spines on posterior branchial margin, last small and obsolescent in some specimens. Lateral limit of orbit unarmed; infraorbital margin with small spine. Rostrum truncate, as long as broad, length 0.6 postorbital carapace length and breadth 0.4 that of carapace; distance between distalmost lateral incisions 0.20 distance between proximalmost lateral incisions; dorsal surface nearly horizontal in lateral view, with numerous small scale-like setose ridges; lateral margin with 4 deeply incised teeth, distal pair small.

Pterygostomian flap rugose, unarmed, ridges with short setae, anterior margin ending in spine.

Sternum: As long as broad, lateral extremities gently divergent posteriorly.

Abdomen: Somites 2–4 each with 2 or 3 uninterrupted and 0–1 interrupted transverse ridges on tergite; somite 5 with 4 uninterrupted ridges; somite 6 with 2 uninterrupted ridges. Telson completely subdivided. Males with G1 and G2.

Eyes: Ocular peduncles 1.1 times longer than broad, maximum corneal diameter 0.7 rostrum width.

Antennule: Article 1 with 4 well-developed distal spines, distodorsal larger, distomesial spine slightly smaller than others. Ultimate article with tuft of fine setae on distodorsal margin.

Antenna: Article 1 with ventral distomesial spine reaching distal margin of article 2. Article 2 with 2 welldeveloped distal spines, distolateral spine slightly longer than distomesial, and reaching midlength of article 3. Article 3 unarmed or with small distomesial spine. Article 4 unarmed.

Mxp3: Ischium with flexor margin ending in small spine, extensor margin ending in acute point; crista dentata with 24 or 25 denticles. Merus shorter than ischium; flexor margin with 3 subequal spines; extensor margin with distal spine. Carpus unarmed.

P1: twice carapace length, with numerous scales with numerous long setae, some of them iridescent. Merus 0.7 times carapace length, 2.2 times as long as carpus, with some spines, dorsomesial and distal spines stronger than others. Carpus 0.8 length of palm, 0.8 times as long as broad; dorsal surface with some spines; mesial margin with row of spines, distal stronger than others. Palm as long as broad, lateral and mesial margins slightly divergent; small spines arranged roughly in dorsal, dorsolateral and dorsomesial rows. Fingers slightly longer than palm, each finger distally with two rows of teeth, spooned; fixed finger with some proximal spines along lateral margin; movable finger with 1–2 proximal spines.

P2–4: long and slender, with setose striae and numerous long plumose setae, some of the iridescent. P2 1.7 times carapace length. Meri successively shorter posteriorly (P3 merus 0.9 length of P3 merus, P4 merus 0.9 length of P3 merus); P2 merus 0.6 carapace length, 2.4 times as long as broad, 1.4 times longer than P2 propodus. Extensor margin with row of 10 or 11 proximally diminishing spines on P2–3, 1 distal spine on P4; ventral margins distally ending in strong spine, lateral sides with 2 or 3 small spines on P4. Carpi with 3 or 4 spines on extensor margin, distalmost smaller than distal second, sometimes absent; lateral surface with 3 or 4 small spines or acute granules sub-paralleling extensor margin; flexor distal margin with small spine. Propodi 2.6–2.9 times as long as broad; extensor margin with 2 or 3 proximal spines; flexor margin with 4–6 slender movable spines. Dactyli distally ending in well-curved strong spine, length 0.8 that of propodi; flexor margin with 4 proximally diminishing teeth, terminal one moderately prominent.

Epipods absent on pereiopods.

Coloration. Base color of carapace and abdomen red, with numerous white spots. Wide transverse whitish or yellowish stripe covering hepatic, anterior branchial and anterior gastric regions; whitish fleck on each posterior branchial region. Rostrum with proximal part reddish, distal part whitish. P1 with numerous small red spots, usually on spines. P2–4 with transverse bluish and whitish bands.

Remarks. This species resembles G. polyphemus n. sp. from the French Polynesia (see Remarks for G. polyphemus ). These two species cannot be differentiated morphologically, and the can be distinguished by their color patterns. The available data suggests that G. polyphemus is restricted to French Polynesia. The genetic divergences with other species are always higher than 13.0% (COI, the closest is G. mauritiana ) and 6.9% (16S rRNA, the closest is G. ceti n. sp.) ( Tab. 1).

Distribution. Maldives Islands, Indonesia ( Ambon), Mariana Islands, Papua New Guinea, New Caledonia, Line Islands, French Polynesia (Society Islands); 1– 45 m.

Figures

FIGURE 84. Galathea pilosa De Man, 1888, holotype, male, 3.7 mm, Indonesia, Moluccas (SMF 214). 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 left Mxp 3, lateral view; E, right P 2, dorsal view; F, right P 4, lateral view. Scale: A, E, F = 1 mm; B – D = 0.5 mm.

FIGURE 119. Dorsal view. A, Galathea pilosa De Man, 1888, Papua New Guinea, ovigerous female 4.5 mm (MNHN-IU- 2013 - 1055). B, Galathea pilosa De Man, 1888, Maldives, male 3.6 mm (UF 39675). C, Galathea platycheles Miyake, 1953, Madagascar, female 2.2 mm (MNHN-IU- 2013 - 13822). D, Galathea platycheles Miyake, 1953, Western Australia, ovigerous female 1.9 mm (UF 22402). E, Galathea politula n. sp., Vanuatu, holotype, M 3.5 mm (MNHN-IU- 2013 - 9707). F, Galathea polydora n. sp., Vanuatu, male 3.3 mm, (MNHN-IU- 2013 - 9871). G, Galathea polydora n. sp., Vanuatu, ovigerous female 2.5 mm (MNHN-IU- 2013 - 13476). H, Galathea polyphemus n. sp., French Polynesia, male 4.4 mm (UF 15427). I, Galathea providentia Laurie, 1926, Madagascar, female 3.0 mm (MNHN-IU- 2013 - 13802).