Galathea perone, 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 : 228-230

Galathea perone n. sp.

( Fig. 82 )

Galathea inconspicua . — Dong & Li, 2010: 12, fig. 7 (South China Sea, 158–220 m).? Galathea inconspicua . — Poore et al., 2011: 332, pl. 10I (color photo, Philippines).

Material examined. Holotype: Philippines. MUSORSTOM 1, Stn CP25, 14°03'N, 120°20’E, 191–200 m, 22 March 1976: F 4.0 mm (MNHN-IU-2013-8500).

Paratypes: Philippines. MUSORSTOM 2, Stn CP35, 13°28'N, 121°12'E, 160–198 m, 24 November 1980: 1 M 3.1 mm (MNHN-IU-2013-8501).

Etymology. From the Greek perone , pin, in reference to the acute rostrum.

Description. Carapace: 1.2 times longer than broad; transverse ridges with dense short setae, without long setae; cervical groove distinct, laterally bifurcated. Gastric region with some transverse ridges: 1 epigastric ridge, scale-like, with 6 small spines; 2 protogastric ridges, anterior ridge uninterrupted, medially convex, with 1 parahepatic spine on each side, posterior interrupted; 2 mesogastric ridges, anterior ridge uninterrupted and not extending laterally to anteriormost of branchial marginal spines, posterior ridge interrupted; 2 metagastric ridges, anterior ridge uninterrupted, not continuing laterally to anteriorbranchial ridge, posterior ridge short. Hepatic region unarmed. Anterior branchial region with distinct ridges. Mid-transverse ridge uninterrupted, preceded by shallow cervical groove. Posterior branchial region with 6 transverse ridges (counting along lateral margin; exclusive of mid-transverse ridge directly behind cervical groove and posteriormost ridge anterior to posterior margin of carapace), 2 ridges uninterrupted. Lateral margins subparallel, with 8 spines: 2 spines in front of and 5 or 6 spines behind anterior cervical groove; first anterolateral, well-developed, slightly behind level of lateral limit of orbit, 1 small spine at midlength between anterolateral spine and anteriormost spine of branchial margin, with small spine ventral to between first and second; 3 spines on anterior branchial region, and 3 spines on posterior branchial margin. Small spine on lateral limit of orbit, 1 or 2 small frontal spines between orbit and anterolateral spine; infraorbital margin with some small spines. Rostrum narrow, 2.5 times as long as broad, length 0.7 postorbital carapace length and breadth 0.3 that of carapace; distance between distalmost lateral incisions 0.20 distance between proximalmost lateral incisions; dorsal surface horizontal, with numerous small scale-like setose ridges; lateral margin with 4 deeply incised teeth.

Pterygostomian flap rugose, unarmed, ridges with short setae, anterior margin acute; upper margin, near linea anomurica, with numerous small teeth.

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

Abdomen: Somites 2–4 each with 2 uninterrupted and 2 interrupted ridges; somite 5 with 2 uninterrupted ridges; somite 6 with 2 medially interrupted ridges.

Eyes: Ocular peduncles 1.5 times longer than broad, maximum corneal diameter 0.8 rostrum width.

Antennule: Article 1 with 2 well-developed distal spines, distodorsal larger, distomesial obsolescent; 1 small spine along lateral margin. Ultimate article with tuft of long 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 longer than distomesial, and barely reaching end of article 3. Articles 3 and 4 unarmed.

Mxp3: Ischium with flexor margins ending in small spine, extensor margin ending in acute angle; crista dentata with 20 or 21 denticles. Merus as long as ischium; flexor margin with 3 spines, proximal spine clearly longer than others, median spine smaller than distal; extensor margin ending in small spine. Carpus unarmed.

P1: 3.8 times carapace length, with numerous setiferous small scales, and some scattered long setae. Merus 1.6 times carapace length, 1.8 times as long as carpus, with numerous spines, dorsomesial and distal spines stronger than others. Carpus 0.9 length of palm, 4.3 times as long as broad; dorsal surface with some small spines; mesial margin with row of spines. Palm 3.9 times longer than broad, lateral and mesial margins subparallel; small spines arranged roughly in dorsal, dorsolateral and dorsomesial rows. Fingers unarmed, 0.9 times palm length, each finger distally with two rows of teeth, spooned.

P2–4: long and slender, with some setose striae and sparse long setae. P2 2.5 times carapace length. Meri successively shorter posteriorly (P3 merus 0.8 length of P2 merus, P4 merus 0.8 length of P3 merus); P2 merus as long as carapace, 7.3 times as long as broad, 1.2 times longer than P2 propodus. P3 merus 5.3 times as long as broad, 1.1 times longer than P3 propodus. P4 merus 4.2 times as long as broad, 0.9 times longer than P4 propodus. Extensor margin with row of 10 or 11 proximally diminishing spines on P2–3, 6 spines on P4; ventral margins distally ending in strong spine, lateral sides with row of small spines on P2–4. Carpi with 6 or 7 spines on extensor margin on P2–4; lateral surface with 5 or 6 small spines sub-paralleling extensor margin; flexor distal margin acute. Propodi 7.0–7.4 times as long as broad; extensor margin with 4 or 5 small proximal spines; flexor margin with 7 or 8 slender movable spines, distal two spines with another smaller spine mesial to them. Dactyli distally ending in well-curved strong spine, length 0.5 that of propodi; flexor margin with 7 or 8 proximally diminishing teeth, distal one clearly larger than penultimate.

Epipods present only on P1.

Remarks. The new species is closely related to G. rhaphidia n. sp. and G. inconspicua Henderson, 1885 (for differentiation, see Remarks of G. inconspicua ).

Distribution. Philippines, South China Sea; 158– 200 m.

Figures

FIGURE 82. Galathea perone n. sp., holotype, female, 4.0 mm, Philippines (MNHN-IU- 2013 - 8500). 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, right P 4, lateral view. Scale: A, F – H = 1 mm; E = 2 mm; B – D = 0.5 mm.