Galathea mariae, 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 : 184-187

Galathea mariae n. sp.

( Figs 66 , 118 B)

Material examined. Holotype: French Polynesia. Society Islands. Moorea Island, 17.4848°S, 149.9172°W, 14 October 2008: M 3.5 mm (UF15522).

Paratypes: French Polynesia. Society Islands. Moorea Island, fore reef between Cook's and Opunohu Bay, 17.4756°S, 149.8344°W, 10–15 m, 19 July 2006: 1 M 2.3 mm (UF9951). Moorea Island, 17.4848°S, 149.9172°W, 14 October 2008: 1 ov. F 3.0 mm (UF15523).— 17.4575°S, 149.8328°W, 10–20 m, 21 October 2009: 1 ov. F 2.5 mm (UF23540).— 17.484°S, 149.9164°W, 19–20 m, 3 November 2009: 1 M 2.9 mm (UF23878).— 17.4856°S, 149.9194°W, 32 m, 10 November 2009: 1 ov. F 2.5 mm (UF23973).— 17.4756°S, 149.8425°W, 13–17 m, 5 December 2009: 1 ov. F 2.1 mm (UF24181). Tuamotu Archipelago. Tenarunga Atoll, 21.3518°S, 136.561°W, 31.8 m, 25 January 2012: 1 M 2.4 mm (UF35380). Gambier Islands. Off Mangareva Island, 23.0566°S, 134.9989°W, 30.1 m, 30 January 2013: 1 M 2.0 mm (UF35418).— 23.0776°S, 134.8884°W, 22.5 m, 6 February 2013: 1 F 1.9 mm (UF35478). Austral Islands. Rapa, Stn 32, 27°35.8'S, 144°23.0'W, 15–20 m, 18 November 2002: 2 M 2.0– 2.3 mm, 1 ov. F 2.4 mm, 1 F 2.2 mm (MNHN-IU-2013-8444).—Stn 33, 27°34.8'S, 144°20.8'W, 30 m, 19 November 2002: 1 ov. F 2.2 mm, 1 F 2.1 mm (MNHN-IU-2013-8445).

Kiribati. Line Islands, Vostok Island, 10.059°S, 152.314°W, 10 m, 24 October 2013: 1 ov. F 2.7 mm (UF38737).

New Caledonia, Maitre Island, 25 m, 19 September 1978: 1 M 1.7 mm, 3 ov. F 1.9–2.2 mm, 3 F 1.7–1.8 mm (MNHN-IU-2013-8440). Lifou Island. LIFOU, Stn 1430, 20°47.5'S, 167°07.1'E, 20–25 m, 9 November 2000: 1 F 2.2 mm (MNHN-IU-2013-8442), 2 M 2.1–2.3 mm, 4 F 2.2–2.7 mm (MNHN-IU-2013-8443).—Stn 1455, 20°56.8'S, 167°02.7'E, 15–20 m, 25 November 2000: 4 M 1.8–2.1 mm, 9 ov. F 2.0–3.0 mm (MNHN-IU-2013- 8438).—Stn 1421, 20°52.4'S, 167°08.5'E, 4 m, 26 November 2000: 3 M 2.0– 3.1 mm, 1 ov. F 1.9 mm, 2 F 2.3–2.7 mm (MNHN-IU-2013-8441), 1 M 2.2 mm (MNHN-IU-2013-8439).

Maldives Islands, Dharanboodhoo Island, 3.0613°N, 72.9311°E, 10–30 m, 12 May 2014: 1 M 2.3 mm, 1 ov F 1.8 mm (UF39637).

Etymology. Named to Maria García of the Centre d’Estudis Avançats de Blanes (CEAB-CSIC), for her support to marine research.

Description. Carapace: As long 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, scalelike, with 2 median spines; 2 protogastric ridges, anterior ridge uninterrupted, medially convex, posterior scale-like or absent; 2 mesogastric ridges, anterior ridge medially interrupted, and not extending (holotype) or extending (most paratypes) laterally to anteriormost of branchial marginal spines, posterior ridge scale-like or absent; 2 metagastric ridges, anterior ridge medially interrupted, 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 4 transverse ridges, 2 ridges uninterrupted. Lateral margins slightly convex, with 7 or 8 spines: 2 or 3 spines in front of and 5 spines behind anterior cervical groove; first anterolateral, well-developed, at level of lateral limit of orbit, 1 small spine at midlength between anterolateral spine and anteriormost spine of branchial margin, with well-developed spine ventral to between first and second; 2 small spines on anterior branchial region, and 3 spines on posterior branchial margin. Spine slightly below lateral limit of orbit; infraorbital margin with strong spine. Rostrum moderately short, 1.5 times as long as broad, length 0.5–0.6 postorbital carapace length and breadth 0.3 that of carapace; distance between distalmost lateral incisions 0.35 distance between proximalmost lateral incisions; dorsal surface slightly concave medially, with numerous small setae; lateral margin with 4 shallowly incised teeth.

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

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

Abdomen: Somites 2–3 each with 2 uninterrupted ridges; somites 4–6 smooth; posteriormedian margin of somite 6 straight. Males with G1 and G2.

Eyes: 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 smaller than others. Ultimate article with a few long fine setae on distodorsal margin.

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

Mxp3: Ischium with flexor and extensor margins ending in acute angle; crista dentata with 29 or 30 denticles. Merus slightly longer than ischium; flexor margin with 2 well-developed spines, proximal spine slightly longer than distal; extensor margin ending in 1 spine. Carpus unarmed.

P1: 3.4–3.5 times carapace length, with numerous setiferous small scales, some scattered long simple setae and some plumose ones. Merus 1.3 times carapace length, 1.5 times as long as carpus, with numerous spines, dorsomesial and distal spines stronger than others. Carpus 0.7 length of palm, 2.6 times as long as broad; dorsal surface with numerous small spines; mesial margin with row of spines. Palm 3.4 times longer than broad, lateral and mesial margins subparallel; numerous small spines arranged roughly in dorsal, dorsolateral and dorsomesial rows; dorsomesial row continuing along fixed finger. Fingers 0.4 times palm length, each finger distally with two rows of teeth, spooned; movable finger unarmed.

P2–4: long and slender, with some setose striae, sparse long simple and plumose setae. P2 1.9 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 0.8 times carapace length, 3.0 times as long as broad, 1.5 times longer than P2 propodus; P3 merus 3.2 times as long as broad, 1.5 times longer than P3 propodus; P4 merus 3.0 times as long as broad, 1.2–1.3 times longer than P4 propodus. Extensor margin with row of 11 or 12 proximally diminishing spines on P2–3, 0–2 small spines on P4; ventral margins distally ending in strong spine, lateral sides unarmed. Carpi with 4 or 5 spines on extensor margin on P2–3, unarmed on P4; lateral surface with some granules sub-paralleling extensor margin; flexor distal margin acute. Propodi 4.0–5.0 times as long as broad; extensor margin unarmed; flexor margin with 4 or 5 slender movable spines, distal two spines with another smaller spine mesial them. Dactyli distally ending in well-curved strong spine, length 0.4–0.5 that of propodi; flexor margin with 4 or 5 proximally diminishing teeth.

Epipods present on P1.

Coloration. Base color whitish, with large reddish or brownish flecks covering median portions of carapace and abdomen. Base of rostrum whitish. P1 translucent whitish, with some red bands, one white large spot on distal part of palm. P2–4 translucent whitish, with red stripes.

Remarks. Galathea mariae closely resembles G. atua n. sp. from the French Polynesia and G. eridani n. sp. from Mozambique and New Caledonia. It can be easily distinguished from the latter two new species by the rostral lateral teeth shallowly incised in G. m a r i a e, rather than deeply incised in the other species. Furthermore, G. m a r i a e is also close to G. denticulata Macpherson & Cleva, 2010 from the southwestern Indian Ocean, but the two can be easily distinguished for one another by the following characters:

- One small hepatic spine is present on each side in G. denticulata , whereas this spine is absent in the new species.

- The Mxp3 merus has one distal spine on the extensor margin of merus in G. m a r i a e, rather than unarmed in G. denticulata .

- The base color is light orange, and the anterior part of the carapace is bluish in G. denticulata , whereas the base color is red, with some whitish large spots on the carapace and abdomen in the new species.

The new species is also close to G. whiteleggii Grant & McCulloch, 1906 from Australia (see Remarks of the latter species).

The genetic divergences with other species are always higher than 9.2% (COI, the closest is G. villosa n. sp.) and 8.5% (16S rRNA, the closest is G. eione n. sp. ( Tab. 2 ).

Distribution. French Polynesia (Society, Austral, Gambier Islands, Line Islands), New Caledonia, and Maldive Islands, 4–32 m, associated with sponges.

Figures

FIGURE 66. Galathea mariae n. sp., holotype, male, 3.5 mm, French Polynesia (UF 15522). A, carapace and abdomen, dorsal view; B, thoracic sternites 3 and 4; C, right pterygostomian region, lateral view; D, left part of cephalothorax, ventral view, showing antennular and antennal peduncles, and anterior part of pterygostomian flap; E, ischium, merus and carpus of right Mxp 3, lateral view; F, right P 1, dorsal view; G, right P 2, lateral view; H, right P 4, lateral view (setae on pereiopods not figured). Scale: A, C, F – H = 1 mm; B, D, E = 0.5 mm.

FIGURE 118. Dorsal view. A, Galathea maculiabdominalis Baba, 1972, Vanuatu, male 2.4 mm (MNHN-IU- 2013 - 8344). B, Galathea mariae n. sp., French Polynesia, ovigerous female 3.0 mm (UF 15523). C, Galathea mauritiana Bouvier, 1914, Madagascar, female 2.5 mm (IU- 2013 - 9740). D, Galathea minima n. sp., Papua New Guinea, ovigerous female 2.8 mm (MNHN-IU- 2013 - 704). E, Galathea minima n. sp., Papua New Guinea, ovigerous female 2.5 mm (MNHN-IU- 2013 - 654). F, Galathea ohshimai Miyake & Baba, 1967, Vanuatu, male 2.2 mm (MNHN-IU- 2013 - 13881). G, Galathea parvula n. sp., holotype, ovigerous female 2.9 mm (UF 38286). H, Galathea paulayi n. sp., French Polynesia, male 4.7 mm (UF 15618). I, Galathea peitho n. sp., Papua New Guinea, male 4.0 mm (MNHN-IU- 2013 - 372).