Galathea melobosis, 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 : 190-193

Galathea melobosis n. sp.

( Fig. 68 )

Material examined. Holotype: New Caledonia. Chesterfield Islands. CHALCAL 84, Stn CP12, 20°34.30'S, 158°47.40'E, 67 m, 23 July 1984: M 3.9 mm (MNHN-IU-2013-13617).

Paratypes: Mariana Islands. Guam, Hospital point, 100–106 m, 13.5021°N, 144.7682°E, 18 March 2008: 1 ov. F 3.0 mm (UF13824).

Solomon Islands. SALOMON 1, Stn CP1809, 9°48.385'S, 160°51.193'E, 39–53 m, 3 October 2001: 1 M 2.9 mm (MNHN-IU-2013-13625). Stn DW1811, 9°46.3'S, 160°51.3'E, 182–203 m, 3 October 2001: 1 M 2.9 mm (MNHN-IU-2013-13623). Stn DW1840, 10°17.0'S, 161°43.0'E, 97–223 m, 6 October 2001: 1 M 3.6 mm (MNHN- IU-2013-13624).

Vanuatu. SANTO, Stn EP1, 15°32.5'S, 167°09.0'E, 46–47 3m, 10 September 2006: 4 M 2.4–3.7 mm, 2 ov. F 2.5–2.8 mm, 1 F 2.9 mm (MNHN-IU-2013-13647).—Stn DB16 Light, 15°35.5'S, 167°15.8'E, 32–40 m, 14 September 2006: 1 ov. F 2.4 mm (MNHN-IU-2013-13654).—Stn EP10, 15°38.0'S, 167°13.6'E, 45–101 m, 15 September 2006: 2 M 2.7–3.2 mm, 2 ov. F 2.8–3.1 mm, 1 F 1.5 mm (MNHN-IU-2013-13648).—Stn AT14, 15°24'S, 167°13.5'E, 102–120 m, 19 September 2006: 1 ov. F 2.8 mm (MNHN-IU-2013-13653).—Stn AT53, 15°31.8'S, 167°13.6'E, 62–71 m, 2 October 2006: 1 ov. F 4.5 mm (MNHN-IU-2013-13618).—Stn AT56, 15°36.1'S, 167°01.3'E, 98–105 m, 2 October 2006: 1 F 2.4 mm (MNHN-IU-2013-13950).—Stn FP50, 15°36.8'S, 167°08.7'E, 25 m, 4 October 2006: 1 M 2.8 mm (MNHN-IU-2013-13652).—Stn EP30, 15°37.6'S, 167°05.4'E, 103–120 m, 12 October 2006: 1 F 3.7 mm (MNHN-IU-2013-13649).—Stn FB80, 15°33.1'S, 167°09.6'E, 2 m, 14 October 2006: 1 F 3.3 mm (MNHN-IU-2013-13650).—Stn FB90, 15°35'S, 167°07.7'E, 36–39 m, 16 October 2006: 1 M 2.9 mm, 1 ov. F 3.0 mm (MNHN-IU-2013-13651).

New Caledonia. Chesterfield Islands. CHALCAL 84, Stn DC10, 20°36.09’S, 161°05.82’E, 87 m, 15 July 1984: 2 M 3.4–3.8 mm, 3 ov. F 3.0– 3.2 mm, 1 F 2.6 mm (MNHN-IU-2013-13635).—Stn CP12, 20°34.30’S, 158°47.40’E, 67 m, 23 July 1984: 22 M 3.4–4.0 mm, 33 ov. F 3.0– 4.2 mm, 7 F 2.8–3.2 mm (MNHN-IU-2013- 13633).—Stn D41, 20°34.80’S, 158°47.30'E, 67 m, 23 July 1984: 1 M 3.9 mm (MNHN-IU-2013-13621); 1 ov. F 4.0 mm (MNHN-IU-2013-13622).—Stn D42, 20°38.00’S, 158°43.10’E, 67 m, 23 July 1984: 5 M 2.8–3.7 mm, 2 ov. F 3.3–3.4 mm (MNHN-IU-2013-13642).—Stn D43, 20°41.50’S, 158°38.40’E, 78 m, 23 July 1984: 1 M 3.4 mm (MNHN-IU-2013-13643).—Stn D52, 21°13.40’S, 158°49.20’E, 69 m, 24 July 1984: 1 ov. F 2.7 mm (MNHN- IU-2013-13644).—Stn D53, 21°19.50’S, 158°55.30’E, 60 m, 24 July 1984: 1 M 3.7 mm, 2 ov. F 3.0– 3.5 mm (MNHN-IU-2013-13645).—Stn CP14, 21°13.50’S, 158°50.20’E, 66 m, 24 July 1984: 8 M 2.9–4.0 mm, 5 ov. F 3.7–3.9 mm, 2 F 3.8 mm (MNHN-IU-2013-13634).—Stn CP15, 21°24.90’S, 159°09.30’E, 60 m, 25 July 1984: 1 M 3.7 mm (MNHN-IU-2013-13636).—Stn CP16, 21°41.67'S, 159°21.92'E, 53 m, 25 July 1984: 3 M 3.4–4.7 mm (MNHN-IU-2013-13637). CORAIL 2, Stn CP22, 20°33’S, 161°01’E, 85–88 m, 22 July 1988: 2 M 3.0– 3.8 mm, 2 ov. F 4.2–4.3 mm (MNHN-IU-2013-13638).—Stn CP23, 20°31’S, 161°04’E, 80–83 m, 22 July 1988: 1 M 2.4 mm (MNHN-IU-2013-13639).—Stn CP25, 20°25'S, 161°05'E, 67–70 m, 22 July 1988: 2 M 2.3–3.0 mm, 1 ov. F 3.0 mm (MNHN-IU-2013-13640).—Stn CP29, 20°31’S, 160°53’E, 79–84 m, 22 July 1988: 1 M 2.4 mm, 1 ov. F 3.4 mm (MNHN-IU-2013-13641).—Stn CP127,19°28’S, 158°27’E, 44–45 m, 29 July 1988: 1 ov. F 4.5 mm (MNHN- IU-2013-13646). Belona Island. CORAIL 1, August 1988: 14 M 2.7–3.6 mm, 5 ov. F 3.2–3.9 mm (MNHN-IU- 2013-13632). South Reef, Stn 400, 22°34'S, 167°14'E, 64 m, 23 January 1985: 1 ov. F 3.6 mm, 1 F 4.0 mm (MNHN-IU-2013-13631).—Stn 561, 22°42'S, 166°59'E, 48 m, 16 July 1985: 1 ov. F 3.5 mm (MNHN-IU-2013- 13630). BATHUS 2, Stn DW714, 22°37'S, 167°09'E, 124 m, 10 May 1993: 1 ov. F 2.8 mm (MNHN-IU-2013- 13629).

Fiji. MUSORSTOM 10, Stn CP1364, 18°11.95'S, 178°34.50'E, 80–86 m, 15 August 1998: 1 M 3.2 mm (MNHN-IU-2013-13620); 1 M 2.7 mm (MNHN-IU-2013-8294); 1 ov. F 3.6 mm (MNHN-IU-2013-13619). SUVA 2, Stn CP48, 17°56.2'S, 177°14.3'E, 16 m, 19 October 1998: 7 M 3.0– 5.7 mm, 4 ov. F 3.1–5.7 mm (MNHN-IU- 2013-13628).—Stn DW50, 17°44.9'S, 177°13.8'E, 36 m, 20 October 1998: 1 M 4.0 mm (MNHN-IU-2013- 13626).—Stn CP66, 17°45.1'S, 177°13.7'E, 37 m, 21 October 1998: 5 M 3.2–4.1 mm, 4 ov. F 4.0– 4.2 mm (MNHN-IU-2013-13627).

Etymology. Melobosis is one of the children of the Ocean in Greek mythology. Considered as a substantive in apposition.

Description. Carapace: As long as broad; transverse ridges with dense short setae, and some scattered moderately long non plumose setae; cervical groove distinct, laterally bifurcated. Gastric region with some transverse ridges: 1 epigastric ridge unarmed, uninterrupted, medially convex; 2 protogastric ridges, anterior one uninterrupted, medially convex, with minute parahepatic spine on each side, sometimes absent, posterior ridge short, scale-like; 1 mesogastric ridge usually medially interrupted but not extending laterally to anteriormost of branchial marginal spines; 2 metagastric ridges, anterior one uninterrupted, continuing laterally to anteriorbranchial ridges, sometimes medially interrupted, posterior ridge short. Hepatic region with small spine near first marginal (anterolateral) spine. Anterior branchial region with distinct ridges. Mid-transverse ridge uninterrupted, preceded by shallow cervical groove, followed by 5 ridges, 1 of them uninterrupted. Lateral margins well convex medially, with 6 or 7 spines: 2 spines in front of and 4 or 5 spines behind anterior cervical groove; first anterolateral, welldeveloped, 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 or 3 spines on posterior branchial margin, last small and obsolescent in some specimens. Small spine on lateral limit of orbit; infraorbital margin with strong spine. Rostrum 1.5–1.6 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 0.30–0.35 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.

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

Abdomen: Somites 2–4 each with 2 uninterrupted transverse ridges on tergite; somites 5 and 6 each with 2 medially interrupted ridges. Males with G1 and G2.

Eyes: Ocular peduncles 1.5 times longer than broad, maximum corneal diameter 0.8 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 2 distal spines, distolateral spine longer than distomesial, and 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 or 21 denticles. Merus as long as ischium; flexor margin with 2 subequal spines; extensor margin unarmed. Carpus unarmed.

P1: 3.4 times carapace length, with numerous setiferous scales, and some scattered long setae. Merus 1.2–1.4 times carapace length, 1.6–2.0 times as long as carpus, with some spines, dorsomesial and distal spines stronger than others. Carpus 0.7–0.8 length of palm, 1.5–2.0 times as long as broad; dorsal surface with some small spines; mesial margin with row of spines, distal slightly stronger than others. Palm 1.6–2.1 times longer than broad, lateral and mesial margins slightly divergent; small spines arranged roughly in dorsal, dorsolateral and dorsomesial rows. Fingers 0.6–0.7 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, with some setose striae and sparse long plumose setae. P2 1.9–2.0 times carapace length. Meri successively shorter posteriorly (P3 merus 0.8–0.9 length of P2 merus, P4 merus 0.8–0.9 length of P3 merus); P2 merus 0.7–0.8 carapace length, 3.6–4.2 times as long as broad, 1.4 times longer than P2 propodus. Extensor margin with row of 7 or 8 proximally diminishing spines on P2–3, 1 distal spine on P4; ventral margins distally ending in strong spine, lateral sides with 0–2 small spines on P4. Carpi with 3–5 spines on extensor margin on P2–3, 0–1 distal spine on P4, distalmost smaller than distal second, sometimes absent; lateral surface with 3 or 4 small spines or acute granules sub-paralleling extensor margin; flexor distal margin acute. Propodi 3.8–4.7 times as long as broad; extensor margin with 0–3 minute proximal spines; flexor margin with 4–6 slender movable spines. Dactyli distally ending in well-curved strong spine, length 0.6–0.7 that of propodi; flexor margin with 4 or 5 proximally diminishing teeth, terminal one moderately prominent.

Epipods present only on P1.

Remarks. The closest relative of Galathea melobosis n. sp. is G. ternatensis De Man, 1902 from Indonesia ( Moluccas, Ternate), Philippines, Papua New Guinea and the Solomon Islands (see Remarks of G. ternatensis ).

Distribution. Mariana Islands, Solomon Islands, Vanuatu, New Caledonia, Chesterfield Islands, Fiji; 2– 223 m.

Figures

FIGURE 68. Galathea melobosis n. sp., holotype, male, 3.9 mm, New Caledonia, Chesterfield Islands (MNHN-IU- 2013 - 13617). 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, F – H = 1 mm; E = 2 mm; B – D = 0.5 mm.