Galathea aurata, Macpherson & Rodríguez-Flores & Machordom, 2025

Galathea aurata sp. nov.

( Figs. 4 View FIGURE 4 , 5 View FIGURE 5 )

Material examined. Holotype: Philippines, Mindoro , Puerto Galera, 13°30.46’N, 120°58.59’E, 28 April 2015, 10 m: ov. F 2.8 mm ( UF43289 ). GoogleMaps

Paratypes: same station than holotype: 1 M 2.3 mm ( UF43289 B) .

Etymology. From the Latin auratus, gold, in reference to the type locality (Mindoro = an alliteration of gold mine in Spanish).

Description. Carapace: Slightly broader than long; cervical groove distinct, laterally bifurcated. Gastric region with some transverse ridges: 1 epigastric ridge unarmed, uninterrupted, medially convex; 2 protogastric ridges, anterior one medially interrupted, without parahepatic spine, posterior ridge short, scale-like, with long thick simple setae; 1 mesogastric ridge medially uninterrupted but not extending laterally to anteriormost of branchial marginal spines; 2 metagastric ridges, anterior one medially interrupted, continuing laterally to anteriorbranchial ridges, posterior ridge short, scale-like. Hepatic region with small spine near first marginal (anterolateral) spine. Anterior branchial region with distinct short ridges. Mid-transverse ridge uninterrupted, preceded by shallow cervical groove, followed by 4–5 ridges, 2 of them uninterrupted. Lateral margins well convex medially, with 6 spines: 2 spines in front of and 4 spines behind anterior cervical groove; first anterolateral, well-developed, at same level of lateral limit of orbit, second, small, at midlength between anterolateral spine and anteriormost spine of branchial margin, with small spine ventral to between first and second; 2 spines on anterior branchial region, last small, and 2 spines on posterior branchial margin, last small and obsolescent in some specimens. Lateral limit of orbit unarmed; infraorbital margin with strong spine. Rostrum 1.1 times as long as broad, length 0.5–0.6 postorbital carapace length and breadth 0.4 that of carapace; distance between distalmost lateral incisions 0.2 distance between proximalmost lateral incisions; dorsal surface nearly horizontal in lateral view, 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.

Thoracic sternum: 0.8 × as wide as long. Sternite III with median shallow notch. Sternite IV with anterior part wider than sternite III, with some short striae. Sternites IV–VI with a few striae on lateral sides. Sternite III ~ 1.8 × as wide as long; sternite IV nearly 2.7 × as wide as long, and 3.0 × as wide as sternite III.

Pleon: Tergites II and III each with 2 transverse uninterrupted ridges on tergite, anterior ridge more distinctly elevated than posterior ridge; tergite of somites IV–VI with posterior minute scale-like ridges; posteromedian margin straight. Males with G1 and G2.

Eye: 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, distomesial spine slightly smaller than others. Ultimate article with tuft of fine setae on distodorsal margin.

Antenna: Article 1 with ventral distomesial spine reaching distal margin of article 2. Article 2 with distolateral and distomesial spines subequal, and barely reaching midlength of article 3. Articles 3 and 4 unarmed.

Mxp3: Ischium with flexor and extensor margins ending in blunt angle or with small spine; crista dentata with 20–21 denticles. Merus shorter than ischium; flexor margin with 2 subequal spines; extensor margin with small distal spine. Carpus unarmed.

P1: 2.2 times carapace length. Merus as long as carapace length, 1.5 times as long as carpus, with some spines, dorsomesial and distal spines stronger than others. Carpus 0.9 length of palm, 1.4 times as long as broad; dorsal surface with several small spines; mesial margin with row of spines, distal slightly stronger than others. Palm 1.4 times longer than broad, lateral and mesial margins slightly divergent; small spines arranged roughly in dorsal, dorsolateral and dorsomesial rows. Fingers 0.9 times palm length, each finger with two rows of teeth distally spooned; fixed finger with some proximal spines along lateral margin; movable finger unarmed.

P2–4: Long and slender. P2 1.3 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 0.5 carapace length, 3.1 times as long as broad, 1.6 times longer than P2 propodus. Extensor margin with row of 6–7 proximally diminishing spines on P2–3, 1 minute distal spine on P4; ventral margins distally ending in strong spine, lateral sides with 0–2 small spines on P4. Carpi with 3–4 spines on extensor margin on P2-3, 0–1 distal spine on P4, distalmost smaller than distal second, sometimes absent; lateral surface with 3–4 acute granules sub-paralleling extensor margin; flexor distal margin acute. Propodi 2.8–3.0 times as long as broad; extensor margin with 0–2 small proximal spines; flexor margin with 5–6 slender movable spines, terminal spines paired. Dactyli distally ending in well-curved strong spine, length 0.7 that of propodi; flexor margin with 4–5 proximally diminishing teeth, terminal tooth moderately prominent.

Epipods present only on P1.

Setae: Three types of setae were observed, (1) short plumose setae, with setules along both sides of shaft, densely located on ridges of carapace and pleon, and scales of P1–4; (2) long thick simple setae, sparsely located on carapace, pleon, and P1–4; (3) short thick simple setae, sparsely located on carapace, pleon and P1–4.

Colour in life. Carapace greenish-brownish, distal half of rostrum with numerous white spots. Pleon light brown, with numerous white spots of different size. Corneae whitish with some small red spots. P1–4 reddishbrownish, with whitish distal part of P1 fingers and P2–4 dactyli.

Genetic data. COI.

Remarks. Galathea aurata is morphologically and genetically very close to G. melobosis Macpherson & Robainas-Barcia, 2015 from the Mariana Islands, Solomon Islands, Vanuatu, New Caledonia, Chesterfield Islands, Fiji, between 2 and 223 m. Both species can be differentiated by the following aspects:

—The rostrum is 1.5–1.6 × as long as wide in G. melobosis , instead of as long as wide in the new species.

—The distomesial spine of the antennal article 1 exceeds the end of the article 3 in G. melobosis , whereas this spine only reaches the end of the article 2 in G. aurata .

—The P2–4 are more slender in G. melobosis than in the new species. The P2 is 1.9–2.0 times the carapace length in G. melobosis , whereas it is about 1.3 times in the new species. The P2–4 propodi are 3.8–4.7 times as long as broad in G. melobosis , whereas they are 2.8–3.0 times as long as broad in the new species.

—Genetically the new species diverges from G. melobosis by 6.70% for COI.

Distribution. Philippines, Mindoro, at 10 m.