Leiogalathea dido, Rodríguez-Flores & Macpherson & Machordom, 2019

Rodríguez-Flores, Paula C., Macpherson, Enrique & Machordom, Annie, 2019, Revision of the squat lobsters of the genus Leiogalathea Baba, 1969 (Crustacea, Decapoda, Munidopsidae) with the description of 15 new species, Zootaxa 4560 (2), pp. 201-256 : 227-230

Leiogalathea dido n. sp.

( Figs. 9 , 10I )

Type material. Holotype: New Caledonia. HALIPRO 2 Stn BT 55, 25°04'S, 168°44'E, 1098–1480 m, 17 November 1996: ov. F 9.8 mm (MNHN-IU-2013-17431).

Paratypes: New Caledonia. BATHUS 3 Stn CP 823, 23°22'S, 167°51'E, 980–1000 m, 29 November 1993: 4 M 5.9–8.5 mm, 1 ov. F 6.9 mm (MNHN-IU-2014-13708) .

New Caledonia. HALIPRO 2 Stn BT 25, 25°17'S, 170°24'E, 1100–1348 m, 11 November 96: 1 F 3.6 mm (MNHN-IU-2013-17403).— Stn BT 55, 25°04'S, 168°44'E, 1098–1480 m, 17 November 1996: 1 M 10.2 mm (MNHN-IU-2013-17432), 12 M 3.9–11.2 mm, 5 ov F 6.0– 8.5 mm, 4 F 5.0– 5.9 mm (MNHN-IU-2013-17402), 1 ov. F 6.0 mm (MNHN-IU-2013-17430), 10 M 2.8–10.8 mm, 8 ov. F 2.7–4.1 mm (MNHN-IU-2013-17433).— Stn BT 58, 25°05'S, 168°45'E, 1303–1500 m, 17 November 96: 7 M 4.3–7.1 mm, 2 ov. F 7.1–9.2 mm (MNHN-IU- 2014-13712) .

New Caledonia. NORFOLK 2 Stn DW2055 , 23°39.23'S, 168°16.43'E, 900–950 m, 24 October 2003: 1 F 5.0 mm (MNHN-IU-2014-13745) .

New Caledonia. EBISCO Stn DW2488 , 23°50'S, 161°42'E, 932–996 m, 0 5 October 2005: 1 F 4.6 mm (MNHN-IU-2014-13783) .

Etymology. From the name Dido, the queen of Carthage in the Aeneid. The name is considered a substantive in apposition.

Description. Carapace: 1.1–1.3 × as long as broad. Mid-transverse ridge usually uninterrupted, preceded by deep cervical groove, followed by 5 or 6 interrupted or scale-like transverse ridges. Lateral margins convex, with 7 spines: first spine anterolateral, well-developed; strong spine on hepatic margin, smaller than first spine; 3 welldeveloped spines on anterior branchial margin, decreasing in size posteriorly, and 2 spines on posterior branchial margin, last spine small. Rostrum horizontal or directed slightly downwards, dorsally flattish or slightly concave, 1.1–1.2 × as long as broad, length 0.2–0.3 × and breadth 0.2–0.3 × that of carapace; lateral margin with 3–6 spines decreasing in size distally.

Sternum: Sternite 3 moderately broad, 2.5–2.8 × as wide as long, anterior margin with median notch flanked by 2 lobes, moderately produced anterolaterally. Sternite 4 narrowly contiguous to sternite 3; surface depressed in midline, smooth; greatest width 2.6 × that of sternite 3, 2.1 × as wide as long.

Abdomen: Tergites 2–3 each with 2 elevated transverse ridges, tergite 4 with transverse ridge, tergites 5–6 with scale-like ridges or smooth; tergite 6 with transverse posteromedian margin.

Eye: Ocular peduncle slightly broader than long, cornea subglobular, maximum corneal diameter 0.4–0.5 × rostrum width, clearly narrower than eyestalk, 0.7 × maximum peduncle width.

Antennule: Article 1 with distomesial angle minutely serrated; lateral margin serrated along distal part.

Antenna: Article 1 with strong distomesial spine nearly reaching end of article 2; article 2 with distolateral and distomesial spines of subequal size, not reaching end of article 3; articles 3 and 4 unarmed.

Mxp3: Ischium as long as merus measured along extensor margin; flexor margin sharply ridged, terminating in well-developed spine; extensor margin unarmed; crista dentata finely denticulate; merus having flexor margin with strong median spine and with or without minute distal spine, extensor margin with distal spine.

P1: 2.3–3.1 (males), 1.8–2.3 (females) × carapace length, with numerous short striae, and densely covered by uniramous short setae on merus to dactylus. Merus 0.6–0.7 length of carapace, 2 × as long as carpus, with strong mesial and distal spines, and some scattered dorsal spines. Carpus slightly shorter than palm, 1.7 × as long as broad, dorsal surface with scattered spines, mesial and lateral margins each with 2 strong spines. Palm, 1.8 × as long as broad, armed with spines in irregular longitudinal rows on mesial and lateral margins, dorsal surface unarmed. Fingers unarmed, as long as or slightly longer than palm.

P2–4: Moderately slender, somewhat compressed laterally, with short setiferous striae on dorsal surface, with some long and thick setae on ischium to dactylus, meri successively shorter posteriorly (P3 merus 0.9 × of length P2 merus, P4 merus 0.8 × of length P3 merus). P2 merus 0.7 × carapace length, 4.5 × as long as broad, 1.2 × as long as P2 propodus; P3 merus 4.2 × as long as broad, 1.2 × as long as P3 propodus; P4 merus 3.5–3.6 × as long as broad, as long as P4 propodus; extensor margins with row of 7 or 8 proximally diminishing spines on P2–3; unarmed on P4; lateral surface unarmed; flexor margin with well-developed distal spine and several additional projecting scales. Carpi with 2–4 spines on extensor margin on P2–3, unarmed on P4, lateral side smooth; flexor margin with small distal spine. Propodi 5.5–6.5 × as long as broad in P2–4, flexor margin with 4–6 movable spinules. Dactyli 0.5–0.6 × length of propodi; distal claw short, moderately curved; flexor margin nearly straight, with 8–10 small teeth along entire margin decreasing in size proximally, each with slender movable spinule, ultimate tooth most nearly always contiguous to base of distal claw than to penultimate tooth.

Colour in life. Unknown.

Genetic data. COI and 16S ( Table 2).

Distribution. New Caledonia and Norfolk Ridge, in sponges, from 670 to 1480 m.

Remarks. Leiogalathea dido belongs to the group of species having the hepatic margin of the carapace armed with one spine. The new species is easily differentiated from the other species of the genus by the reduced cornea, being clearly narrower than the ocular peduncle. This species is morphologically related to L. turnus from New Caledonia and adjacent waters, having a low genetic distances between them (see below under the Remarks of L. turnus ).

Figures

FIGURE 9. Leiogalathea dido n. sp., holotype, ov. F 9.8 mm, New Caledonia (MNHN-IU-2013-17431). A, carapace and abdomen, dorsal view. B, sternites 3–4. C, cephalic region, showing antennular and antennal peduncles, ventral view. D, right Mxp3 ischium and merus, lateral view. E, right P1, dorsal view. F, right P2, lateral view. G, dactylus of right P2, lateral view. H, right P3, lateral view. I, left P4, lateral view. Scales: A, E, F, H, I = 1.0 mm; B–D, G = 0.5 mm.

FIGURE 10. Rostrum, and ocular peduncle, dorsal view. A, Leiogalathea achates n. sp., holotype, ov. F 3.6 mm (MNHN-IU- 2016-7125). B, L. aeneas n. sp., holotype, F 7.6 mm (SMF51246). C, L. agassizii (A. Milne Edwards, 1880), F 6.9 mm (SMF51247), Florida. D, L. amata n. sp., holotype, F 3.6 mm (MNHN-IU-2014-13779). E, L. anchises n. sp., holotype, F 6.4 mm (MNHN-IU-2014-13786). F, L. ascanius n. sp., holotype, M 5.9 mm (MNHN-IU-2013-17425). G, L. camilla n. sp., holotype, M 3.0 mm, (MNHN-IU-2014-13728). H, L. creusa n. sp., holotype, F 5.0 mm (MNHN-IU-2014-13716). I, L. dido n. sp., holotype, ov. F 9.8 mm (MNHN-IU-2013-17431). Scale = 1 mm.