Galathea pubipes, 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 : 257-259

Galathea pubipes n. sp.

( Fig. 92 )

Material examined. Holotype: New Caledonia. HALIPRO 1, Stn CP869, 21°14.84'S, 165°55.49'E, 450–490 m, 23 March 1994: 1 ov. F 7.8 mm (MNHN-IU-2013-15940).

Paratypes: New Caledonia. MUSORSTOM 4, Stn CP170, 18°57.00’S, 163°12.60’E, 485 m, 17 September 1985: 1 M 8.1 mm, 4 ov. F 5.8–7.3 mm (MNHN-IU-2013-15943); 1 ov. F 5.4 mm (MNHN-IU-2013-15944).—Stn CP195, 18°54.80'S, 163°22.20'E, 465 m, 19 September 1985: 1 ov. F 7.0 mm (MNHN-IU-2013-13943).—Stn CC201, 18°55.80’S, 163°13.80’E, 490 m, 20 September 1985: 1 ov. F 7.6 mm (MNHN-IU-2013- 13945). HALIPRO 1, Stn CP869, 21°14.84'S, 165°55.49'E, 450–490 m, 23 March 1994: 1 ov. F 6.5 mm (MNHNIU-2013-15941). BATHUS 4, Stn CP909, 18°57.64’S, 163°10.30’E, 516–558 m, 4 August 1994: 1 M 7.0 mm, 1 ov. F 8.7 mm (MNHN-IU-2013-15942).

Etymology. From the Latin pubes, pubescent, covered with down or fine short hair.

Description. Carapace: As long as broad; transverse ridges with dense short setae, without long setae (sometimes 1 or 2 on cardiac region); cervical groove distinct, laterally bifurcated; most ridges on gastric region interrupted, with numerous scattered scale-like ridges; epigastric region with 10–13 small spines; 2 small hepatic and 1–3 small parahepatic spines on each side; anterior branchial region with scale-like ridges. Mid-transverse ridge uninterrupted, preceded by shallow cervical groove, followed by 10 or 11 ridges, mostly interrupted. Lateral margins convex medially, with 9 or 10 spines: 2 spines in front of and 7 or 8 spines behind anterior cervical groove; first anterolateral, well-developed, slightly behind level of orbit, second small but distinct, located at midlength between first spine and anteriormost spine of branchial margin, with small 1 or 2 spines ventral to between first and second, sometimes 1 additional minute spine at base of second spine; 3 spines on anterior branchial margin, last small, and 4 or 5 spines on posterior branchial margin, last small. Small outer orbital spine; infraorbital margin with 2 or 3 spines. Rostrum triangular, twice longer than broad, length 0.7 that of, breadth 0.3 that of carapace; distance between distalmost lateral incisions 0.35 distance between proximalmost lateral incisions; dorsal surface flatish, nearly horizontal in lateral view, with some unirramous setae; lateral margin with 4 moderately incised sharp teeth.

Pterygostomian flap rugose, with sparse short setae, anterior margin bluntly angular.

Sternum: About as long as broad; lateral extremities gently divergent posteriorly.

Abdomen: Somites 2–3 each with 3 or 4 uninterrupted transverse ridges on tergite, anterior ridge slightly more elevated than posterior ridges; somite 4 with 2 ridges, posterior ridge medially interrupted; somites 5 and 6 each with 2 medially interrupted ridges, posteriormedian margin of somite 6 straight. Males with G1 and G2.

Eyes: Ocular peduncles 1.3 times longer than broad, maximum corneal diameter 0.6 rostrum width.

Antennule: Article 1 with 3 well-developed distodorsal and distolateral spines, distodorsal larger; distomesial spine smaller than others. Ultimate article with a few short fine setae on distodorsal margin.

Antenna: Article 1 with distomesial spine barely reaching midlength of article 2. Article 2 with 2 subequal distal spines, reaching midlength of article 3. Articles 3 and 4 unarmed.

Mxp3: Ischium with well-developed spine on flexor distal margin; crista dentata with 20–22 denticles. Merus slightly shorter than ischium; flexor margin with 2 spines, proximal clearly stronger than distal; extensor margin with 1 distinct distal spine. Carpus unarmed.

P1: 3.0–3.2 times carapace length, with numerous finely setiferous scales, with some long thick setae. Merus 1.3 times length of carapace, 2.2 times as long as carpus, with spines arranged roughly in rows, dorsomesial spines stronger; distal spines prominent. Carpus 0.7 length of palm, 2.4 times as long as broad; dorsal surface with small spines arranged roughly in longitudinal rows; mesial row of well-developed spines. Palm 2.5 times longer than broad, lateral and mesial margins with small spines arranged roughly in dorsolateral and dorsomesial rows, a few small spines scattered on dorsal side. Fingers as long as palm, each finger distally with two rows of teeth, spooned; mesial margin of movable finger and lateral margin of fixed finger unarmed.

P2–4: Moderately long and slender, with setose striae and long plumose setae. P2 1.8 times carapace length. Meri successively shorter posteriorly (P3 merus 0.8 length of P2 merus, P4 merus 0.8 length of P3 merus); P2 merus 0.7 carapace length, 4.4 times as long as broad, 1.3 times longer than P2 propodus; P3 merus 3.5 times longer than broad, as long as P3 propodus; P4 merus 3.0 times as long as broad, 0.9 length of P4 propodus. Extensor margins of meri with row of 9 or 10 proximally diminishing spines on P2–3, 3 spines on P4; flexor margins distally ending in strong spine followed proximally by 1 or 2 small spines and several tubercles or eminences; lateral sides with some minute spines on P3–4. Carpi with 6 or 7 spines on extensor margin, distalmost longer than distal second; lateral surface with 4 or 5 small spines and acute granules sub-paralleling extensor margin on P2–4; flexor distal margin acute. Propodi 4.8–5.3 times as long as broad; extensor margin with 2 or 3 small proximal spines on P2–3; flexor margin with 5–7 slender movable spines on P2–4. Dactyli distally ending in well-curved strong spine, length 0.4–0.5 that of propodi; flexor margin with 5 proximally diminishing teeth, terminal one prominent.

Epipods on P1.

Remarks. Galathea pubipes n. sp. is close to G. pascualae n. sp. from Indonesia to New Caledonia, but the two can be easily distinguished by the following characters:

- The carapace has numerous scale-like ridges on the gastric and anterior branchial regions in G. pubipes , whereas there are only a few scale-like ridges on these regions in G. pascualae .

- The posterior branchial margin has 10 ridges, mostly interrupted, in G. pubipes , instead of 6 ridges, some of them uninterrupted, in G. pascualae .

- The rostrum is flatish in G. pubipes , instead of slightly concave in G. p a s c u a l a e.

- The P1 carpus is short, being 2.4 times as long as broad in G. pubipes , whereas the P1 carpus is elongate, being 3.3–3.6 times as long as broad in G. pascualae .

The genetic divergences between the two species are 16.1% (COI) and 10.0% (16S rRNA). The divergences among G. pascualae , G. pubipes and all other sequenced species are larger than 15%(COI) and 9% (16S rRNA) ( Tab. 2 ).

Distribution. New Caledonia, 450– 558 m.

Figures

FIGURE 92. Galathea pubipes n. sp., holotype, ovigerous female, 7.8 mm, New Caledonia (MNHN-IU- 2013 - 15940). 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; E = 2 mm; B – D = 0.5 mm.