Galathea hispidissima, 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 : 137-139

Galathea hispidissima n. sp.

( Fig. 46 )

Material examined. Holotype: Solomon Islands. SALOMON 2, Stn CP2286, 08°39.54'S, 157°23.18'E, 248–253 m, 6 November 2004: M 4.5 mm (MNHN-IU-2013-15945).

Paratypes: Solomon Islands. SALOMON 2, Stn CP2286, 08°39.54'S, 157°23.18'E, 248–253 m, 6 November 2004: 1 ov. F 5.4 mm (MNHN-IU-2013-15946); 2 M 3.3–4.3 mm, 4 F 3.6–4.2 mm (MNHN-IU-2013-13982).

Etymology. From the Latin hispidus, hairy, bristly, in reference to the setose ridges on the body.

Description. Carapace: As long as broad; transverse ridges with dense short setae, without long setae; cervical groove distinct, laterally bifurcated; 6 or 7 uninterrupted transverse ridges on gastric region, and some scale-like ridges in epigastric region; epigastric region unarmed (paratype) or with 4 small spines (holotype); hepatic region unarmed (paratype) or with 3 or 4 small hepatic spines on each side (holotype); anterior branchial region with scale-like ridges. Mid-transverse ridge uninterrupted, preceded by shallow cervical groove, with 1 small spine on each side (holotype), absent in paratypes; posterior branchial region with 10–12 transverse ridges. Lateral margins slightly convex medially, with 8 spines: 2 spines in front of and 6 spines behind anterior cervical groove; first anterolateral, small, at level of orbit, second very small but distinct, located at midlength between first spine and anteriormost spine of branchial margin, with small spine ventral to between first and second; 3 spines on anterior branchial margin, last small, and 3 spines on posterior branchial margin, last small. Outer orbital spine unarmed; infraorbital margin with some teeth; minute spine between orbit and first anterolateral spine. Rostrum widely triangular, 1.7–1.9 times as long as broad, length 0.7 that of, breadth 0.3–0.4 that of carapace; distance between distalmost lateral incisions 0.35 distance between proximalmost lateral incisions, dorsal surface 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: Longer than broad. Sternite 4 clearly broader than following sternites.

Abdomen: Somites 2–5 each with 4 or 5 uninterrupted or interrupted transverse ridges on tergite; somite 6 with 1 uninterrupted ridge and 1 medially interrupted ridge. 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 2 well-developed distodorsal and distolateral spines, distodorsal larger; distomesial spine obsolescent; 0-2 small spines on lateral margin. Ultimate article with tuft of fine setae on distodorsal margin.

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

Mxp3: Ischium with well-developed spine on flexor distal margin; crista dentata with 18–20 denticles. Merus clearly shorter than ischium; flexor margin with 2 spines, proximal stronger than distal; extensor margin with 1 distinct distal spine. Carpus unarmed.

P1: 3.4–4.8 times carapace length, with numerous finely setiferous scales. Merus 1.4–2.0 times length of carapace, 1.7–1.9 times as long as carpus, with spines arranged roughly in rows, dorsomesial spines stronger; distal spines prominent, dorsal and lateral spines small. Carpus 0.9 length of palm, 3.1–3.4 times as long as broad; dorsal surface with small spines arranged roughly in longitudinal rows; mesial spines longer than others. Palm 3.1–3.4 times longer than broad, dorsal side, lateral and mesial margins with minute spines. Fingers 0.7–0.9 length of 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 setae. P2 1.6 times carapace length. Meri successively shorter posteriorly (P3 merus 0.7–0.8 length of P2 merus, P4 merus 0.8 length of P3 merus); P2 merus 0.6–0.7 carapace length, 3.6–3.7 times as long as broad, 1.6–1.7 times longer than P2 propodus; P3 merus 2.5–2.7 times longer than broad, 1.1–1.4 times longer than P3 propodus; P4 merus 2.1–2.6 times as long as broad, 0.9–1.1 length of P4 propodus. Extensor margins of meri with row of 9 or 10 proximally diminishing spines on P2–3, 6 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 unarmed or with 1–3 small spines on P4. Carpi with 5 or 6 spines on extensor margin, distalmost longer than distal second; lateral surface with 4 or 5 small spines or acute granules subparalleling extensor margin on P2–4; flexor margin with distal spine. Propodi 3.0–3.4 times as long as broad; extensor margin with 1 or 2 small proximal spines on P2–3; flexor margin with 4 or 5 slender movable spines on P2–4. Dactyli distally ending in well-curved strong spine, length 0.6–0.9 that of propodi; flexor margin with 5 or 6 proximally diminishing teeth, terminal one prominent.

Epipods on P1.

Remarks. Galathea hispidissima is characterized by the uninterrupted main gastric ridges on the carapace, the carapace lateral margin armed with one small but distinct spine between the anterolateral spine and the anteriormost branchial marginal spine, and the antennular basal article only with two well-developed terminal spines. These characters are shared with G. albatrossae Baba, 1988 , G. h i s p i d a Baba, 2005, G. inconspicua Henderson, 1885 , G. pubescens Stimpson, 1858 and related species. However, G. hispidissima is easily distinguished by the shape of the sternites 4 and 5. The sternite 4 is distinctly broader than the sternite 5 in the new species. In the other species, the sternite 4 is clearly narrower than the sternite 5.

No genetic data are available for this species.

Distribution. Solomon Islands, 248– 253 m.

Figures

FIGURE 46. Galathea hispidissima n. sp., holotype, male, 4.5 mm, Solomon Islands (MNHN-IU- 2013 - 15945). A, carapace and abdomen, dorsal view; B, sternal plastron; 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, left P 4, lateral view. Scale: A, F – H = 1 mm; E = 2.0 mm; B – D = 0.5 mm.