Leiogalathea juturna, 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 : 235-237

Leiogalathea juturna n. sp.

( Figs. 11C , 14 )

Leiogalathea laevirostris .— Baba et al. 2009: 134, figs. 112–114.

Dubious identification: Leiogalathea laevirostris .— Baba 2005: 88, 246.

Type material. Holotype: Kei Islands , Indonesia, KARUBAR Stn DW18 , 05°18'S, 133°01'E, 205–212 m, 24 October 1991: 1 F 4.2 mm (MNHN-IU-2013-17404).

Paratypes: Kei Islands , Indonesia. KARUBAR Stn DW18 , 05°18'S, 133°01'E, 205–212 m, 24 October 1991: 1 F 3.3 mm (MNHN-IU- 2016-2996), 3 F 3.3–4.0 mm (MNHN-IU-2013-17428), 2 M 4.2–4.4 mm (MNHN-IU-2013- 17427). — Stn CP 25, 05°30'S, 132°52'E, 336–346 m, 26 October 1991: 1, M, 5.4 mm (MNHN-IU-2013-17426) .

Etymology. From the name Juturna, Turnus ’s sister 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 medially interrupted or scalelike, preceded by shallow cervical groove, followed by 5 or 6 interrupted or scale-like transverse ridges. Lateral margins slightly convex and subparallel, with 2 small spines: first spine anterolateral; second spine on anterior branchial margin; hepatic and posterior branchial margin unarmed. Rostrum horizontal, dorsally flattish or slightly concave, 1.2–1.4 × as long as broad, length 0.3 × and breadth 0.2–0.3 × that of carapace; lateral margin with 4 or 5 rudimentary teeth.

Sternum: Sternite 3 moderately broad, 3.3–4.0 × as wide as long, anterolaterally produced, anterior margin serrated, straight, with a median minute shallow notch. Sternite 4 narrowly contiguous to sternite 3; surface depressed in midline, smooth; greatest width 3 × that of sternite 3, 2.5 × as wide as long.

Abdomen: Tergites 2–3 each with 2 elevated transverse ridges, tergite 4 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 serrated; lateral margin smooth.

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

P1: 2.5–2.7 (males), 2.0 (females) × carapace length, with numerous short striae, and covered by uniramous long setae on merus to dactylus. Merus 0.7 length of carapace, 2.1 × as long as carpus, with strong mesial and distal spines, and scattered dorsal spines. Carpus slightly shorter than palm, 1.6 × as long as broad, dorsal surface with a few scattered spines, mesial and lateral margins with several spines. Palm 2.1 × as long as broad, armed with spines in irregular longitudinal rows along mesial and lateral margins, dorsal surface unarmed. Fingers 1.3 × as long as palm; fixed finger unarmed; movable finger with 1 proximal mesial spine.

P2–4: Stout, with setiferous setose striae on dorsal surface, somewhat compressed laterally, with sparse 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 0.6 × carapace length, 6 × as long as broad, 1.4 × as long as P2 propodus; P3 merus 4.8 × as long as broad, 1.5 × as long as P3 propodus; P4 merus 3.3 × as long as broad, 1.3 × as long as P4 propodus; extensor margins with row of 7–8 proximally diminishing spines on P2, unarmed on P3–4; lateral surface unarmed; flexor margin with well-developed distal spine and several additional projecting scales on. Carpi with 2–4 spines on extensor margin on P2–3, unarmed on P4, lateral side smooth; flexor margin with small distal spine. Propodi 4.0–5.0 × as long as broad on P2–4, flexor margin with 4–6 movable spinules. Dactyli 0.5 × length of propodi; distal claw short, moderately curved; flexor margin nearly straight, with 7 or 8 small teeth along the entire margin decreasing in size proximally, each with slender movable spinule, ultimate tooth closer to base of distal claw than to penultimate tooth.

Colour in life. Ground colour reddish, orange to pale. Carapace and anterior half of abdomen pale orange. P1 occasionally totally orange with orange red bands, tips of fingers whitish; P2–4 with orange or reddish bands (from Baba et al. 2009).

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

Distribution. Indonesia and Taiwan, from 205 to 356 m.

Remarks. Leiogalathea juturna belongs to the group of species having the hepatic margin of the carapace unarmed, the branchial margin with or without a spine, and the rostral lateral margin armed with 4 or 5 rudimentary teeth. The closest relatives are L. paris from French Polynesia, Papua New Guinea and New Caledonia, L. laevirostris from Andaman Sea and L. priam from Papua New Guinea (see below, under the Remarks of L. priam ).

Figures

FIGURE 11. Rostrum, and ocular peduncle, dorsal view. A, Leiogalathea evander n. sp., holotype, M 3.9 mm (MNHN-IU- 2015-820). B, L. imperialis (Miyake & Baba, 1967), holotype, ov. F 5.2 mm (BLIH 205a). C, L. juturna n. sp., holotype, F 4.2 mm (MNHN-IU-2013-17404). D, L. laevirostris (Balss, 1913), syntype, F 4.9 mm (ZMB17488). E, L. pallas n. sp., holotype, F 6.9 mm (MNHN-IU-2014-13395). F, L. paris n. sp., holotype, ov. F 4.0 mm (MNHN-IU-2011-4471). G, L. priam n. sp., holotype, M 5.0 mm (MNHN-IU-2014-13697). H, L. sinon n. sp., holotype, F 8.3 mm (MNHN-IU-2014-13711). I, L. turnus n. sp., holotype, M 8.0 mm (MNHN-IU-2014-13744). Scale = 1 mm.

FIGURE 14. Leiogalathea juturna n. sp., A–D, F–I, holotype, F 4.3 mm, Kei Islands (MNHN-IU-2013-17404). E, paratype, M 4.4 mm, Kei Islands (MNHN-IU-2013-17427). 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, dactylus of left P2, lateral view. H, left P3, lateral view. I, left P4, lateral view. Scales: A, E, G, H, I = 1.0 mm; B–D, F = 0.5 mm. Setae omitted on P1.