Galathea poupini, 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 : 248-250

Galathea poupini n. sp.

( Fig. 89 )

Material examined. Holotype: French Polynesia. Society Islands. Moorea Island, 17.5044°S, 149.7584°W, 74–81 m, 30 January 2012: 1 ov. F 2.8 mm (UF33711).

Etymology. This species is dedicated to Joseph Poupin of the Ecole navale et groupe des écoles du Poulmic, Brest, for his enormous support to crustacean taxonomy.

Description. Carapace: As long as broad; ridges with dense short fine plumose setae, without long setae; cervical groove slightly distinct, laterally bifurcated; gastric and anterior branchial regions only with scale-like or in concentric arcs; 2 median epigastric spines. Posterior branchial region with 5 transverse ridges. Lateral margins convex medially, with 7 spines: 2 spines in front of, and 5 spines behind, anterior cervical groove; first anterolateral, second small, accompanying another spine ventral to between first and second; 2 spines on anterior branchial margin, and 3 spines on posterior branchial margin. External orbital limit ending in small spine; infraorbital margin with 1 or 2 spines. Rostrum broad triangular, 1.5 times as long as broad, length 0.6 postorbital carapace length and breadth 0.4 that of carapace, nearly horizontal in lateral view; distance between distalmost lateral incisions 0.2 distance between proximalmost lateral incisions; dorsal surface with some short setae; lateral margin with 4 deeply incised sharp teeth.

Pterygostomian flap rugose, unarmed, anterior margin blunt.

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

Abdomen: Somites 2–4 with 2 or 3 transverse ridges, anterior ridge more distinctly elevated than posterior ridge; somites 5–6 smooth, with some scale-like ridges, nearly straight lobe on posteromedian margin.

Eyes: Ocular peduncles 1.4 times longer than broad, maximum corneal diameter 0.6 rostrum width.

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

Antenna: Article 1 with ventral distomesial spine not reaching end of article 2. Article 2 with 2 distal spines, distolateral spine larger than distomesial, overreaching midlength of article 3. Articles 3–4 unarmed.

Mxp3: Ischium with well-developed distal spine on flexor margin; extensor and flexor margins ending in spine; crista dentata with 18 denticles. Merus equally long as ischium; flexor margin with 2 subequal spines; extensor margin with small distal spine. Carpus unarmed.

P1: 1.7 times carapace length, relatively slender, somewhat depressed on palm, more so on fingers. Merus as long as carapace, 1.5 times as long as carpus, with spines arranged roughly in rows, distal spines prominent. Carpus as long as palm, twice longer than broad; dorsal surface with small spines arranged roughly in longitudinal rows; mesial margin with 2 strong spines. Palm 1.5 times longer than broad, lateral and mesial margins subparallel; spines arranged roughly in rows; dorsolateral row continuing on to lateral margin of fixed finger. Fingers as long as palm, each finger distally with two rows of teeth and spooned; movable finger with row of dorsomesial spines.

P2–4: moderately slender, with setose striae and sparse plumose setae. P2 1.6 times carapace length. Meri successively shorter posteriorly (P3 merus 0.9 length of P3 merus, P4 merus 0.8 length of P3 merus); P2 merus 0.6 carapace length, 3.6 times as long as broad, 1.3 times longer than P2 propodus. Extensor margin with row of 8–10 proximally diminishing spines on P2–3, 1 small distal spine on P4; ventral margins distally ending in strong spine followed proximally by 1 or 2 spines and several eminences, lateral sides with 1 small spine on P4. Carpi with 2 spines on extensor margin on P2; unarmed on P3–4; lateral surface with 2 or 3 spines or acute granules subparalleling extensor margin; flexor distal margin blunt. Propodi 4.0–4.3 times as long as broad; extensor margins unarmed; flexor margin with 5 or 6 slender movable spines. Dactyli distally ending in well-curved strong spine, length 0.6–0.7 that of propodi; flexor margin with 4 or 5 proximally diminishing teeth, terminal one prominent.

Epipods on P1–2.

Remarks. The new species belongs to the group of species characterized by scale-like ridges on the gastric region and the absence of dorsal spines on the branchial regions. However, G. poupini is easily differentiated from the other closely related species (e.g. G. submagnifica Laurie,1926 , G. waiora n. sp.) by the presence of epipods on P1 and 2, instead of P1 only in the other species.

Distribution. French Polynesia, Moorea Island; 74– 81 m.

Figures

FIGURE 89. Galathea poupini n. sp., holotype, ovigerous female, 2.8 mm, French Polynesia (UF 33711). 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; B – D = 0.5 mm.