Galathea spinosorostris Dana, 1852

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 : 289-291

Galathea spinosorostris Dana, 1852

( Figs 104 , 120 H)

Galathea spinoso-rostris Dana, 1852: 480 (Sandwich Islands, Hawaiian Islands).— Dana, 1855: pl. 30, figs 9a, 9b, 9c.

Galathea spinosorostris .— Castro, 2011: 14 (list of Hawaii occurrences).

Dubious identifications:

Galathea spinosirostris [sic].— Henderson, 1893: 431 (Muttuwar Par and Gulf of Martaban).

Galathea spinosorostris .— De Man, 1888: 456 ( Ambon).— Baba, 1988: 78 (South China Sea off SW Luzon, off N Luzon, Waikiki Reef, and Honolulu, 22–410 m).— Wu et al., 1998: 9, figs 15, 21B ( Taiwan).— Komai, 2000: 353 (list).— Kawamoto & Okuno, 2003: 95, unnumbered fig. (Kume-jima, Okinawa, 10 m).— Baba, 2005: 245 (key, synonymies).— Kawamoto & Okuno, 2006: 95, unnumbered fig. (Kume-jima, Okinawa, 10 m).—Baba et al., 2008: 77 (in part, compilation).— Dong & Li, 2010: 20 (South China Sea, 22–410 m).

Galathea algae . — Baba, 1982b: 59 ( Palau Islands and Yap Island, subtidal).— Peyrot-Clausade, 1989: 112 (Tuamotu Archipelago, 5–30 m).— Poupin, 1996: 20 (compilation of French Polynesia records).

Not Galathea spinosorostris .— Johnson, 1970: 6, fig. 1b ( Singapore, low tide to 3.6 m) (= G. coralliophilus Baba & Oh, 1990 ).

Not Galathea spinosorostris . — Laurie, 1926: 124 (Providence, Seychelles, Amirante, Saya de Malha Bank, Cargados Carajos, Chagos, 13–81 m).— Tirmizi & Javed, 1993: 59, fig. 26 (Andaman Sea and N Madagascar, 1.5–772 m).— Macpherson & Cleva, 2010: 62, color fig 3F ( La Réunion, Mayotte, 10–30 m) (= G. eulimene n.sp.).

Material examined. Neotype: Hawaii. Oahu Island, off Kewalo, 21.289°N, 157.865°W, 9–12 m, 1 December 2008: F 1.5 mm (UF15249).

Hawaii. Maui, Palis, Scenic Lookout, 2–20 m, 15 October 2004: 1 ov. F 2.0 mm (UF8325). French Frigate Shoals. 23.6577°N, 166.0738°W, 24 m, 13 October 2006: 1 M 3.0 mm (UF12053); 1M 2.3 mm (UF12081); 6 M 1.4–2.5 mm, 1 ov. F 2.5 mm, 1 F 2.6 mm (UF12085).— 23.699°N, 166.0575°W, 18 m, 19 October 2006: 1 F 2.2 mm (UF12200).— 23.8632°N, 166.1842°W, 25 m, 21 October 2006: 1 M 2.4 mm, 3 ov. F 2.3–2.5 mm (UF12075).— 23.8633°N, 166.1877°W, 28 m, 26 October 2006: 1 ov. F 2.4 mm (UF12376).— 23.8538°N, 166.3267°W, 1.5 m, 26 October 2006: 1 M 3.0 mm, 1 F 2.0 mm (UF12982); 1 M 2.6 mm (UF13161).—Oahu Island, off Kewalo, 21.289°N, 157.865°W, 9–12 m, 1 December 2008: 1 F 2.6 mm (UF15247); 1 M 2.2 mm (UF15248); 1 ov. F 1.7 mm.—Hawaii, no date: 1 M 3.1 mm (UF20157).

Marquesas Islands. Stn LC119, 9°59,976'S, 139°07,831'W, 27–35 m, 15–16 January 2012: 1 M 3.7 mm 1,ov. F 2.8 mm (MNHN-IU-2013-15981).

Description. Carapace: slightly broader than long; transverse ridges with dense very short setae, without long plumose setae; cervical groove distinct, laterally bifurcated. Gastric region with 5 transverse ridges: 1 epigastric ridge scale-like, with 2 spines (rarely 4–6); 2 mesoagstric ridges, anterior one uninterrupted, not extending laterally to anteriormost branchial spines, posterior ridge scale-like; 2 metagastric ridges arcuate. One small parahepatic spine and one hepatic spine, near anterolateral spine, on each side. Anterior branchial region with distinct scale-like ridges. Mid-transverse ridge uninterrupted, preceded by shallow cervical groove, followed by 3or 4 ridges, 2 of them uninterrupted. Lateral margins slightly convex, with 7 spines: 2 spines in front of, and 5 spines behind, anterior cervical groove; first anterolateral, well-developed, at same level of lateral limit of orbit, second small, with spine ventral to between first and second spines; 2 spines on anterior branchial region, and 3 spines on posterior branchial margin, last small. Spine on lateral limit of orbit; infraorbital margin with strong spine. Rostrum 1.3 as long as broad, length 0.6 postorbital carapace length and breadth 0.4 that of carapace; distance between distalmost lateral incisions 0.25 distance between proximalmost lateral incisions; dorsal surface nearly horizontal in lateral view, with some short setae; lateral margin with 4 deeply incised sharp teeth.

Pterygostomian flap rugose, unarmed, ridges with short setae, anterior margin acute.

Sternum: 0.8 times as long as broad, lateral extremities gently divergent posteriorly.

Abdomen: Somites 2–4 with 2 transverse uninterrupted ridges; somites 5 and 6 each with 2 uninterrupted or medially interrupted ridges; somite 6 with posteriomedian margin slightly convex. Males with G1 and G2.

Eyes: Ocular peduncles 1.3 times longer than broad, maximum corneal diameter 0.7 rostrum width.

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

Antenna: Article 1 with ventral distomesial spine reaching distal margin of article 2. Article 2 with 2 subequal distal spines, reaching midlength of article 3. Article 3 with small distomesial spine. Article 4 unarmed.

Mxp3: Ischium with small spine on flexor and extensor distal margins; crista dentata with 19–21 denticles. Merus as long as ischium; flexor margin with 2 well-developed spines, distal spine slightly larger than proximal spine; extensor margin with distal spine. Carpus with 2 or 3 spines or acute granules along extensor margin.

P1: 2.5 times carapace length, somewhat depressed on palm, more so on fingers, covered with finely setiferous scales, with numerous long simple setae (not figured). Merus as long or slightly longer than carapace, 1.7 times as long as carpus, with spines arranged roughly in rows, dorsomesial spines stronger; distal spines prominent. Carpus as long as palm, 2.3 times as long as broad; dorsal and lateral surfaces with some spines; mesial margin with 3 or 4 spines (distal second strong). Palm 2.3 times longer than broad, lateral and mesial margins slightly convex; strong spines arranged roughly in dorsolateral and dorsomesial rows, continuing along fixed and movable fingers, respectively; a few well-developed spines scattered on dorsal side. Fingers 0.8 times as long as palm, each finger distally with two rows of teeth, spooned.

P2–4: moderately slender, with setose striae and sparse long plumose setae. P2 twice carapace length. Meri successively shorter posteriorly (P3 merus 0.9 length of P3 merus, P4 merus 0.8 length of P2 merus); P2 merus 0.7 carapace length, 3.0 times as long as broad, 1.5 times longer than P2 propodus; P3 merus 3.7 times as long as broad, 1.5 times longer than P3 propodus; P4 merus 3.0 times as long as broad, as long as P2 propodus. Extensor margin of P2–3 meri with row of 6–8 proximally diminishing spines, 4 spines on P4; ventral margins distally ending in strong spine followed proximally by 0–1 spines and several eminences; lateral sides unarmed. Carpi with 5 or 6 spines on extensor margin on P2–3, 1 or 2 spines on P4; lateral surface with 2–4 granules sub-paralleling extensor margin; flexor distal margin acute. P2–4 propodi 3.8–4.2 times as long as broad; extensor margin with 3 or 4 proximal spines on P2–4; flexor margin with 4 or 5 slender movable spines. Dactyli distally ending in wellcurved strong spine, length 0.6–0.7 that of propodi; flexor margin with 4 or 5 proximally diminishing teeth, terminal one prominent.

Epipods present on P1.

Coloration. Base color translucent whitish or reddish, with numerous minute red spots on carapace and abdomen. Cardiac region with 2 white spots; abdominal somites with some white spots. P1 with reddish band on distal part of merus, carpus and palm. P2–4 each with distal red band on merus and white band on distal part of propodus.

Remarks. This species was described by Dana (1852) using specimens from Sandwich Islands (= Hawai'ian Islands). Unfortunately the types were lost during the Great Chicago Fire in 1871 (see also Evans 1967), so we have selected a neotype to facilitate further studies. The species has been recorded from numerous localities of the Indian and Pacific oceans, but the genetic data have confirmed the existence of some different species that can be separated by subtle morphological characters. Therefore many literature records need revision. Nevertheless, the occurrence of the species is restricted to Hawaii and eastern part of French Polynesia at present.

Galathea spinosorostris is characterized by the carapace lateral margin bearing one small but distinct spine between the anterolateral spine and the anteriormost spine on the branchial margin, non-scale-like some gastric ridges including uninterrupted anterior protogastric ridge, the possession of two epigastric spines (rarely 4–6), one pair of hepatic and parahepatic spines, the presence of three well-developed terminal spines on the antennular basal article, and the possession of epipod only on P1. These characteristics are also shared by G. algae Baba, 1969 from Japan, G. cephyra n. sp. from New Caledonia and G. eulimene n. sp. from the western Indian Ocean. Galathea spinosorostris can be easily distinguished from the latter three species by the following characters:

- The P1 movable finger has a row of well-developed marginal spines in G. spinosorostris , whereas this finger is unarmed in the other three species.

- The posteriomedian margin of the abdominal somite 6 is convex in G. spinosorostris , instead of usually transverse in the other three species.

The genetic divergence of COI between G. e u l i m e n e and G. spinosorostris is large, 17.2% Unfortunately, sequence data on G. algae and G. cephyra are not available at present.

Distribution. Hawaii and Marquesas Islands; 1– 35 m.

Figures

FIGURE 104. Galathea spinosorostris Dana, 1852, neotype, ovigerous female, 1.7 mm, Hawaii (UF 15249). A, carapace and abdomen, dorsal view; B, sternal plastron; C, left part of cephalothorax, showing antennular and antennal peduncles; D, ischium, merus and carpus of right Mxp 3, lateral view; E, left P 1, dorsal view; F, right P 2, lateral view; G, right P 3, lateral view; H, right P 4, lateral view; I, abdominal somite 6, dorsal view. Scale: A, E – H, I = 1 mm; B – D = 0.5 mm (setae on appendages not figured).

FIGURE 120. Dorsal view. A, Galathea pubescens Stimpson, 1858, Vanuatu, male 6.2 mm (MNHN-IU- 2013 - 15948). B, Galathea punctata n. sp., Vanuatu, ovigerous female 5.0 mm (MNHN-IU- 2013 - 8491). C, Galathea rubrispina n. sp., Papua New Guinea, holotype, male 2.4 mm (MNHN-IU- 2013 - 377). D, Galathea schnabelae n. sp.. Maldives, holotype, male 3.3 mm (UF 40283). E, Galathea scolopia n. sp., Papua New Guinea, male 3.8 mm (MNHN-IU- 2011 - 4479). F, Galathea senta n. sp., Vanuatu, ovigerous female 3.4 mm (MNHN-IU- 2013 - 14361). G, Galathea sinensis Dong & Li, 2010, Vanuatu, ovigerous female 5.7 mm (MNHN-IU- 2013 - 8229). H, Galathea spinosorostris Dana, 1852, Hawaii, female 2.2 mm (UF 12200). I, Galathea subsquamata Stimpson, 1858, Papua New Guinea, male 3.8 mm (MNHN-IU- 2013 - 13503).