Galathea rubrispina, 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 : 268-271

Galathea rubrispina n. sp.

( Figs 96 , 120 C)

Material examined. Holotype: Papua New Guinea. PAPUA NIUGINI, Stn PD14, 05°12.3'S, 145°47.9'E, 10–15 m, 11 November 2012: 1 M 2.4 mm (MNHN-IU-2013-377).

Etymology. From the Latin rubra, red, and spina, thorn, in reference to the presence of some red spines in the rostrum and pereiopods.

Description. Carapace. As long as broad; anterior cervical groove indistinct; ridges with numerous short setae, without long setae. Gastric region with some transverse ridges: 1 epigastric ridge, medially interrupted, with 2 small spines, 1 median scale-like ridge between epigastric and protogastric ridge; 1 protogastric ridge, medially interrupted, without parahepatic spines, and not extending laterally to carapace margin, 1 median scale-like ridge between protogastric and mesogastric ridge; 1 mesogastric ridge uninterrupted and not extending laterally to first branchial spine; 2 metagastric ridges, anterior ridge medially interrupted, not continuing laterally with anterior branchial ridge, posterior ridge short. Mid-transverse ridge uninterrupted, preceded by shallow cervical groove. Posterior branchial region with 5 ridges. Lateral margins medially convex, with 5 spines: 1 spine in front of and 4 spines behind indistinct anterior cervical groove; first anterolateral, well-developed, at same level of lateral limit of orbit, without spine ventral to between first and cervical groove; 2 spines on anterior branchial region, and 2 spines on posterior branchial margin. External orbital limit ending in small spine; infra-orbital margin serrated. Rostrum broad triangular, 1.3 times as long as broad, length 0.6 that of, breadth 0.5 that of carapace; distance between distalmost lateral incisions 0.2 distance between proximalmost lateral incisions; dorsal surface nearly horizontal in lateral view, with few scales; lateral margin with 4 sharp teeth.

Pterygostomian flap rugose, with spine on anterior ridge, anterior margin ending in well-developed spine.

Sternum: Slightly broader than long, lateral limits divergent posteriorly.

Abdomen: Somite 2 with 2 uninterrupted transverse ridges on tergite; somites 3–6 smooth, each with anterior ridge only; posteromedian margin of somite 6 slightly convex. Males with G1 and G2.

Eyes: Ocular peduncles as long as broad, maximum corneal diameter 0.8 rostrum width.

Antennule: Article 1 with 3 well-developed distal spines, distomesial clearly smaller than others. Ultimate article with long tuft of setae on distodorsal margin.

Antenna: Article 1 with depressed ventral distomesial process exceeding distal margin of article 2. Article 2 with 2 subequal distal spines, exceeding midlength of article 3. Articles 3 and 4 unarmed.

Mxp3: Ischium with well-developed distal spine on flexor margin; extensor margin unarmed; crista dentata with 25 denticles. Merus subequal in length to ischium, with 2 spines on flexor margin, proximal one located at midlength, clearly longer than distal spine; extensor margin with small distal spine. Carpus unarmed.

P1. 3.1 times carapace length, with numerous short setae and some scattered long plumose setae on dorsal surface and along lateral and mesial margins of all articles. Merus 1.1 times carapace length, 1.5 times as long as carpus, with rows of spines, mesial and distal spines strong. Carpus 0.8 length of palm, 2.1 times longer than broad, lateral and mesial margins subparallel, dorsal surface with some well-developed spines; mesial surface with row of spines, with some strong spines; and row of small spines along lateral margin. Palm 2.5 times longer than broad, lateral and mesial margins subparallel and with row of spines; small spines roughly in rows on dorsal side; 2 lateral rows not continued on to lateral margin of fixed finger; mesial row not continuing on the mesial margin of movable finger. Fingers 0.5 times palm length, each finger distally with two rows of teeth, spooned.

P2–4: Relatively slender, moderately setose, sparsely with long setae on all articles. P2 1.7 times carapace length. Meri successively shorter posteriorly (P3 merus 0.9 length of P2 merus, P4 merus 0.8 length of P3 merus); P2 merus 0.6 carapace length, 3.0 times as long as broad, 1.4 times longer than P2 propodus; P3 merus 2.7 times as long as broad, 1.3 times length of P3 propodus; P4 merus 2.6 times as long as broad, 1.3 length of P4 propodus. Extensor margin of merus with row of 7 or 8 proximally diminishing spines on P2–3, 2 spines on P4; lateral surface unarmed; flexolateral margins with strong terminal spine and 1 or 2 additional spines on terminal half; flexomesial margins unarmed. Carpi with 4 or 5 spines on extensor margin on P2–3, 3 spines on P4; lateral surface with row of 2–4 small spines or acute granules paralleling extensor row; flexor distal margins with spine. Propodi 4 times as long as broad; extensor margin with 2 or 3 proximal spines; flexor margin with 3 or 4 movable spines. Dactyli subequal in length, 0.6–0.7 length of propodi, ending in incurved, strong, sharp spine; flexor margin with prominent triangular terminal tooth preceded by obsolescent 4 or 5 teeth.

Epipods present on P1–3.

Coloration. Base color whitish to orangish. Some dark orange spots scattered on carapace and abdomen. Tips of rostral spines red. P1 with whitish bands on distal part of merus, carpus, and palm; bluish flecks on distal part of palm and proximal part of fingers; finger tips whitish; spine tips red. P2–4 with orange and whitish bands.

Remarks. Galathea rubrispina n. sp. is closely related to G. minima n. sp. from Papua New Guinea from which it can be distinguished by the following characters:

- There are two spines on the anterior branchial margin in G. rubrispina , instead of three spines in G. m i n i m a. - The gastric region has some scale-like ridges in G. rubrispina , but such scale-like ridges are absent in G. minima .

- The proximal spine on the flexor margin of the Mxp3 merus is much longer than the distal spine in G. rubrispina , whereas they are subequal or slightly unequal in G. minima .

No genetic data are available for G. rubrispina . Distribution. Papua New Guinea, 10– 15 m.

Figures

FIGURE 96. Galathea rubrispina n. sp., holotype, ovigerous female, 3.3 mm, Western Australia (J 13344). 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.

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).