Galathea connudata, 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 : 85-88

Galathea connudata n.sp.

( Fig. 26 )

Material examined. Holotype: Wallis and Futuna. MUSORSTOM 7, Stn DW509, 14°14.8'S, 178°11.5' W, 200–240 m, 12 May 1992: M 3.6 mm (MNHN-IU-2013-8295).

Paratypes: Philippines. MUSORSTOM 1, Stn CP41, 13°58'N, 120°31'E, 208–236 m, 24 March 1976: 1 ov. F 3.6 mm (MNHN-IU-2013-8300). MUSORSTOM 2, Stn DR33, 13°32'N, 121°07'E, 120–137 m, 24 November 1980: 1 ov. F 4.3 mm (MNHN-IU-2013-8301).

Wallis and Futuna. MUSORSTOM 7, Stn DW509, 14°14.8'S, 178°11.5' W, 200–240 m, 12 May 1992: 1 ov. F 4.0 mm (MNHN-IU-2013-8296); 1 ov. F 4.7 mm (MNHN-IU-2013-8297).—Stn CP515, 14°13.5'S, 178°10.3'W, 224–252 m, 12 May 1992: 1 ov. F 2.9 mm (MNHN-IU-2013-8299).

Etymology. From the Latin, connudatus, wholly bare, in reference to the absence of spines on the carapace dorsal surface.

Description. Carapace: Slightly longer than broad; transverse ridges with dense short setae, and some scattered long non-plumose and non-iridescent setae; cervical groove distinct, laterally bifurcated. Gastric region with 6 transverse ridges: 1 epigastric ridge, unarmed, medially interrupted; 2 protogastric ridges, anterior ridge medially interrupted, without parahepatic spines, posterior ridge short, arcuate, with a few long setae; 1 mesogastric ridge, medially interrupted not extending laterally to anteriormost of branchial marginal spines; 2 metagastric ridges, anterior ridge medially interrupted, not fused with anterior branchial ridges, posterior ridge short. Anterior branchial region with distinct ridges. Mid-transverse ridge uninterrupted, preceded by shallow cervical groove. Posterior branchial region with 5 transverse ridges, 2 of them uninterrupted. Lateral margins slightly convex medially, with 5 spines: 1 spine in front of and 4 spines behind anterior cervical groove; first, anterolateral, well-developed, behind level of lateral limit of orbit, no spine ventral to between first and anterior branch of cervical groove; 2 spines on anterior branchial region, and 2 spines on posterior branchial margin. Minute spine on limit of orbit; infraorbital margin with well-developed spine. Rostrum 1.8 times longer than broad, length 0.7 postorbital carapace length and breadth 0.4 that of carapace; distance between distalmost lateral incisions 0.4 distance between proximalmost lateral incisions; dorsal surface flatish, with numerous small setose scales; lateral margin with 4 shallowly 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: Somite 2 with 2 uninterrupted transverse ridges on tergite; somites 3–4 with 2 ridges, posterior medially interrupted ridge; somites 5–6 smooth, posteriormedian margin of somite 6 straight. Males with G1 and G2.

Eyes: Ocular peduncles 1.5 times longer than broad, maximum corneal diameter 0.6 rostrum width.

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

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

Mxp3: Ischium with flexor margins ending in small spine, extensor margin ending in acute angle; crista dentata with 20–23 denticles. Merus shorter than ischium; flexor margin with 2 spines, proximal spine clearly longer than distal; extensor margin unarmed. Carpus unarmed.

P1: 2.5–3.5 times carapace length, with setose scales and numerous long simple non-iridescent setae. Merus 1.3–1.5 times as long as carapace, 1.5–1.7 times as long as carpus, with small spines arranged roughly in rows, dorsomesial and ventromesial spines stronger, distal spines prominent. Carpus as long as palm, 1.7–2.0 times longer than broad; dorsal surface with some small spines arranged roughly in rows; mesial margin with 2 strong spines. Palm 1.8 times longer than broad, lateral and mesial margins subparallel; small spines arranged roughly in dorsolateral and dorsomesial rows. Fingers 0.8–0.9 length of palm, each finger distally with two rows of teeth, spooned; fingers unarmed.

P2–4: moderately short and slender, with some setose striae and numerous long plumose and non-plumose setae, some of them iridescent. P2 1.9–2.0 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 0.7–0.8 carapace length, 3.5–3.9 times as long as broad, 1.3 times longer than P2 propodus. P3 merus 3.0–3.5 times as long as broad, 1.3 times longer than P3 propodus. P4 merus 2.7–3.3 times as long as broad, 1.1 times longer than P4 propodus. Extensor margin with row of 7–9 proximally diminishing spines on P2–3, 2 or 3 spines on P4; ventral margins distally ending in strong spine, lateral sides unarmed on P2–3, 1 or 2 spines on P4; ventromesial margins unarmed. Carpi with 5–7 spines on extensor margin on P2–4; lateral surface with 4 or 5 small spines sub-paralleling extensor margin; flexor distal margin blunty produced. Propodi 3.0–4.0 times as long as broad; extensor margin with 2 or 3 proximal spines; flexor margin with 4 slender movable spines. Dactyli distally ending in well-curved strong spine, length 0.6–0.7 that of propodi; flexor margin with 7 proximally diminishing teeth, terminal one prominent.

Epipods absent on pereiopods.

Remarks. Galathea connudata n. sp. Is closely related to G. anoplos n. sp. from the Solomon Islands from which it can be distinguished by the following characters:

- The rostrum has the rostral lateral teeth shallowly incised in G. connudata , instead of deeply incised in G. anoplos .

- The anterior protogastric ridge is medially interrupted in G. connudata , rather than uninterrupted in G. anoplos . - The proximal spine of the flexor margin of the Mxp3 merus is very strong, nearly reaching the distal margin of the merus in G. anoplos . This spine never reaches the distal margin in G. connudata .

The genetic divergences with other congeneric species are always higher than 13.7% (COI) and 4.6% (16S rRNA) ( Tab. 1). No genetic data are available for G. anoplos .

Distribution. Philippines, Wallis and Futuna, 120– 252 m.

Figures

FIGURE 26. Galathea connudata n. sp., holotype, male, 3.6 mm, Wallis and Futuna (MNHN-IU- 2013 - 8295). 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, left P 3, lateral view; H, right P 4, lateral view. Scale: A, E – H = 1 mm; B – D = 0.5 mm.