Leiogalathea amata, 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 : 215-216

Leiogalathea amata n. sp.

( Figs. 4 , 10D )

Type material. Holotype: Wallis and Futuna. MUSORSTOM 7 Stn DW556 , 11°48.7'S, 178°18.0'W, 440 m, 19 May 1992: F 3.6 mm (MNHN-IU-2014-13779).

Paratypes: Wallis and Futuna. MUSORSTOM 7 Stn DW542 , 12°26.4'S, 177°28.2'W, 370 m, 17 May 1992: 1 M 3.8 mm (MNHN-IU-2014-13778) .

New Caledonia. BATHUS 3 Stn DW807 , 23°40'S, 167°59'E, 420–438 m, 27 November 1993: 1 M 5.2 mm (MNHN-IU-2014-13780) .

Etymology. From the name Amata, queen of Laurentum and wife of Latinus in the Aeneid. The name is considered a substantive in apposition.

Description. Carapace: 1.2–1.3 × as long as broad. Mid-transverse ridge usually interrupted, preceded by shallow cervical groove, followed by 5 or 6 interrupted or scale-like transverse ridges. Lateral margins slightly convex, with 2 spines: first spine anterolateral, well-developed; second small spine on anterior branchial margin, hepatic margin and posterior branchial margin unarmed. Rostrum horizontal, dorsally flattish or slightly concave and slightly inclined downwards, 1.3–1.7 × as long as broad, length 0.4 × and breadth 0.3 × that of carapace; lateral margin unarmed, smooth.

Sternum: Sternite 3 broad, 3.5 × as wide as long, anterolaterally produced, anterior margin slightly sinuous, straight, with a median wide shallow notch. Sternite 4 narrowly contiguous to sternite 3; surface depressed in midline, smooth; greatest width 3.6 × that of sternite 3, 2.6 × as wide as long.

Abdomen: Tergite 2 with 2 elevated transverse ridges, tergites 3–4 each with transverse ridge, tergites 5–6 smooth; tergite 6 with transverse posteromedian margin.

Eye: Ocular peduncle slightly longer than wide; cornea subglobular, maximum corneal diameter 0.7 × rostrum width, as wide as eyestalk.

Antennule: Article 1 with distomesial angle minutely serrated; lateral margin smooth.

Antenna: Article 1 with distomesial spine reaching midlength of article 2; article 2 with strong distomesial spine, longer than distolateral spine, and nearly 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 small spine; extensor margin unarmed; crista dentata finely denticulate; merus having flexor margin with 1 strong median spine, extensor margin with distal spine.

P1: 2.2–2.4 × carapace length, with scattered short striae, and densely covered by uniramous long setae on merus to dactylus. Merus 0.8 length of carapace, twice as long as carpus, with strong mesial and distal spines, and scattered dorsal spines. Carpus 0.8 as long as palm, 1.8 × as long as broad, dorsal surface with several spines, mesial margin with 2 or 3 spines. Palm 1.7 × as long as broad, armed with spines in irregular longitudinal rows along mesial and lateral margins, dorsal surface unarmed. Fingers 1.4 × as long as palm; fixed finger with row of well-developed spines; movable finger with well-developed proximal spine.

P2–4: Slender, somewhat compressed laterally, with short setiferous striae on dorsal surface, with short setae and sparsely with some long and thick setae on ischium to dactylus. Meri successively shorter posteriorly (P3 merus 0.9 × length of P2 merus, P4 merus 0.9 × length of P3 merus). P2 merus as long as or slightly shorter than carapace, 5.3–6.9 × as long as broad, 1.1 × as long as P2 propodus; P3 merus 0.7 × as long as carapace, 4.2 × as long as broad, 1.1 × as long as P2 propodus. P4 merus 4.7 × as long as broad, 1.1 × as long as P4 propodus; extensor margins with row of 6 or 7 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 1–3 spines on extensor margin on P2–3, unarmed on P4, lateral side smooth; flexor margin with small distal spine. Propodi 7.7–8.3 × as long as broad in P2–4, flexor margin with 4–6 movable spinules. Dactyli 0.6 × length of propodi; distal claw short, moderately curved; flexor margin nearly straight, with 6 or 7 small teeth decreasing in size proximally, each with slender movable spinule, ultimate tooth equidistant between base of distal claw and penultimate tooth.

Colour in life. Unknown.

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

Distribution. New Caledonia and Wallis & Futuna, from 370 to 440 m.

Remarks. Leiogalathea amata belongs to the group of species having the hepatic margin of the carapace unarmed and the margin of the rostrum smooth. The species is easily differentiated from the others by the rostrum lacking lateral teeth and the branchial margin of the carapace being armed with one spine. The closest relative is L. imperialis from Sagami Bay (see below under the Remarks of that species).

Figures

FIGURE 4. Leiogalathea amata n. sp., A–D, F–G, holotype, F 3.6 mm, Wallis and Futuna (MNHN-IU-2014-13779); E, paratype, M 3.8 mm, Wallis and Futuna (MNHN-IU-2014-13778). 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, left P2, lateral view. G, left P3, lateral view. Scales: A, E–G = 1.6 mm; B–D = 1.0 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.