Galathea schnabelae, 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 : 273-276

Galathea schnabelae n. sp.

( Figs 98 , 120 D)

Material examined. Holotype: Maldives Islands, Magoodhoo Islands, 3.078913°N, 72.962112°E, 18–23 m, 5 May 2014: M 3.3 mm (UF40283)

Paratypes: same data as holotype: 1 ov. F 2.4 mm (UF39560).

Etymology. This species is dedicated to Kareen Schnabel of the National Institute of Water and Atmospheric Research, Wellington, for her contributions to squat lobster taxonomy.

Description. Carapace: As long as broad; ridges with short fine setae, without long setae; cervical groove slightly distinct, laterally bifurcated; gastric and anterior branchial regions only with interrupted ridges or scale-like ridges; 2 median epigastric spines; without hepatic and parahepatic spines; mid-transverse ridge medially uninterrupted, preceded by shallow cervical groove. Posterior branchial region with 4 ridges, 2 of them medially uninterrupted. Lateral margins slightly convex, with 5 spines: 1 spine in front of and 4 spines behind anterior cervical groove; first anterolateral, well-developed, accompanying another spine ventral to between first spine and anterior cervical groove; 2 spines on anterior branchial margin, and 2 spines on posterior branchial margin. External orbital limit ending in small spine; infraorbital margin with 1 strong spine. Rostrum broad triangular, slightly longer than broad, length 0.5 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 slightly concave, with some short setae; lateral margin with 4 deeply incised sharp teeth.

Pterygostomian flap rugose, anterior margin acutely produced.

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

Abdomen: Somite 2 with 2 transverse ridges, anterior ridge more distinctly elevated than posterior ridge; somites 3–6 smooth, posteromedian margin of somite 6 straight. 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 spines, distodorsal larger; distomesial spine slightly smaller than distoventral. Ultimate article with a few short fine setae, not in tuft, on distodorsal margin.

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

Mxp3: Ischium with well-developed distal spine on flexor margin, crista dentata with 22–25 denticles. Merus longer than ischium; flexor margin with 2 spines, proximal spine slightly stronger than distal; extensor margin unarmed. Carpus unarmed.

P1: 3.0–3.3 times carapace length, relatively slender, with numerous long unirramous setae. Merus 1.1–1.2 times length of carapace, 1.4 times as long as carpus, with spines arranged roughly in rows, some strong spines along mesial margin, distal spines prominent. Carpus 0.8–0.9 length of palm, 2.0–2.4 times as long as broad; dorsal surface with spines arranged roughly in longitudinal rows; mesial margin with 1 strong spine and some welldeveloped spines. Palm 2.0–2.4 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 0.8 length of palm, each finger distally spooned, with two rows of fingers; movable finger unarmed.

P2–4: moderately slender, with setose striae and sparse long non-plumose setae. P2 1.9–2.0 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 0.8 carapace length, 4.0–4.3 times as long as broad, 1.5–1.6 times longer than P2 propodus; P3 merus broader than P2 merus. Extensor margin with row of 8–10 proximally diminishing spines on P2–3, 4 or 5 spines on P4; ventral margins distally ending in strong spine followed proximally by 0–1 spines and several eminences, lateral unarmed. Carpi with 4 or 5 spines on extensor margin on P2–4; lateral surface with 2–4 spines or acute granules sub-paralleling extensor margin; flexor distal margin acute. Propodi 4.7–4.8 times as long as broad; extensor margin with 3–6 proximal spines on P2–4; flexor margin with 4 or 5 slender movable spines. Dactyli distally ending in well-curved strong spine, length 0.5–0.6 that of propodi; flexor margin with 4 proximally diminishing teeth, terminal one prominent.

Epipods on P1.

Coloration. Base color of carapace and abdomen whitish and pale. Whitish and reddish blotch behind rostrum; ridges reddish. P1 with transverse brown and whitish stripes; base of both fingers white. P2–4 with distal part of meri and propodi and dactyli pink, with darker transverse ridges.

Remarks. Galathea schnabelae n. sp. is characterized by the presence of scale-like ridges on the gastric region and the lack of dorsal spines on the branchial regions. The closest relative is G. ploto n. sp. from New Caledonia, Chesterfield Islands. However, G. schnabelae and G. ploto can be separated by the following aspects:

- There is one small but distinct spine between the anterolateral spine and the anteriormost spine on the branchial margin in G. ploto , whereas such a spine is absent in G. schnabelae .

- The carapace bears one hepatic spine on each side in G. schnabelae , whereas this spine is absent in G. ploto .

No genetic data are available for G. schnabelae . Distribution. Maldives, 18– 23 m.

Figures

FIGURE 98. Galathea schnabelae n. sp., holotype, male, 3.3 mm, Maldives Islands (UF 40283). 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, left P 4, lateral view. Scale: A, E – H = 1 mm; B – D = 0.5 mm.

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).