Leiogalathea ascanius, 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 : 220-223

Leiogalathea ascanius n. sp.

( Figs. 6 , 10F )

Leiogalathea laevirostris .— Baba 1991: 487 (in part, only specimens from CHALCAL 2, SMIB 3, SMIB 4, and VOSLMAR).

Type material. Holotype: New Caledonia. NORFOLK 2 Stn DW2027 , 23°26.34'S, 167°51.38'E, 465–650 m, 21 October 2003: M 5.9 mm (MNHN-IU-2013-17425).

Paratypes: New Caledonia. CHALCAL 2 Stn DW73 , 24°40'S, 168°38'E, 573 m, 29 October 1986: 1 M 4.2 mm (MNHN-IU-2014-13770), 1 M 4.2 mm, 3 F 3.6–4.9 mm (MNHN-IU-2016-421).— Stn DW74 , 24°40.36'S, 168°38.38'E, 650 m, 29 October 1986: 3 M, 3.1–3.9 mm, 1 F 3.8 mm (MNHN-IU-2016-420).— Stn DW75 , 24°39.31'S, 168°39.67'E, 600 m, 29 October 1986: 2 M 4.5–4.6 mm (MNHN-IU-2016-419) .

New Caledonia. SMIB 3 Stn DW1 , 24°55.7'S, 168°21.8'E, 520 m, 6 May 1987: 1 ov. F, 4.1 mm (MNHN-IU- 2016-414).—Stn DW2 , 24°53.4'S, 168°21.7'E, 530–537 m, 26 May 1987: 1 M 3.6 mm, 1 ov. F 3.7 mm (MNHN- IU-2016-415) .

New Caledonia. SMIB 4 no station data, 1 F 4.0 mm (MNHN-IU-2016-413).

Hunter and Mathew Islands. VOLSMAR Stn DW5, 22°25.9'S, 171°46.5'E, 700 m, 1 June 1989: 3 M 3.4–5.2 mm (MNHN-IU-2016-417).

New Caledonia. BERYX 11 Stn DW9 , 24°52.10'S, 168°21.95'E, 635–680 m, 15 October 1992: 1 ov. F 3.9 mm (MNHN-IU-2014-13790).—Stn DW10 , 24°52.85'S, 168°21.40'E, 565–600 m, 15 October 1992: 3 M 3.4–3.9 mm, (MNHN-IU-2014-13782) .

New Caledonia. BATHUS 3 Stn DW776 , 24°44' S, 170°08' E, 770–830 m, 24 November 1993: 1 M 5.9 mm (MNHN-IU-2014-13713).—Stn DW778 , 24°43' S, 170°07' E, 750–760 m, 24 November 1993: 5 M 3.0– 4.3 mm, 2 F 3.4–4.5 mm (MNHN-IU-2014-13707), 1 F 3.2 mm (MNHN-IU-2014-13706).—Stn DW794 , 23°48' S, 169°49' E, 751–755 m, 26 November 1993: 1 M 6.0 mm (MNHN-IU-2014-13721).—Stn DW798 , 23°34' S, 169°36' E, 657–660 m, 26 November 1993: 1 F 4.7 mm (MNHN-IU-2014-13710).—Stn DW809 , 23°39' S, 167°58' E, 650– 730 m, 28 November 1993: 1 M 6 mm, 2 F 4.9–5 mm (MNHN-IU-2014-13709) .

New Caledonia. HALIPRO 2 Stn BT 04, 23°31'S, 169°34'E, 790–845 m, 6 November 1996: 1 F 4.9 mm (MNHN-IU-2014-13726).— Stn BT 45, 25°45'S, 167°15'E, 680–780 m, 15 November 1996: 1 F 4.6 mm (MNHN- IU-2014-13725) .

New Caledonia. NORFOLK 1 Stn DW1666 , 23°42'S, 167°43'E, 469–860 m, 20 June 2001: 1 ov. F 4.7 mm, 1 F 4.5 mm (MNHN-IU-2014-13776).—Stn DW1699 , 24°40'S, 168°39'E, 581–600 m, 24 June 2001: 1 M 4.3 mm, 3 ov. F 3.4–3.7 mm (MNHN-IU-2014-13789) .

New Caledonia. NORFOLK 2 Stn DW2027 , 23°26.34'S, 167°51.38'E, 465–650 m, 21 October 2003: 2 M 5.1– 5.5 mm (MNHN-IU-2013-17423), 1 F 4.9 mm (MNHN-IU-2013-17424).—Stn DW2046 , 23°43.87'S, 168°01.03'E, 333–375 m, 23 October 2003: 1 ov. F 5.8 mm (MNHN-IU-2014-13743).—Stn DW2053 , 23°39.64'S, 168°15.60'E, 670–708 m, 24 October 2003: 2 M 4.5–5- 9 mm (MNHN-IU-2014-13756), 1 F 6.6 mm (MNHN-IU- 2014-13755).—Stn DW2057 , 24°40.10'S, 168°39.34'E, 555–565 m, 25 October 2003: 2 M 4.2–4.6 mm (MNHN- IU-2014-13760).—Stn DW2058 , 24°39.76'S, 168°40.43'E, 591–1032 m, 25 October 2003: 3 M 2.5–3.9 mm, 5 F 2.4–4.0 mm (MNHN-IU-2014-13753).—Stn DW2056 , 24°40'S, 168°39'E, 573–600 m, 25 October 2003: 1 M 4.3 mm (MNHN-IU-2014-13757).—Stn DW2064 , 25°17'S, 168°56'E, 609–691 m, 26 October 2003: 1 M 3.1 mm, 3 F 4.0– 4.6 mm (MNHN-IU-2014-13759).—Stn DW2069 , 25°20.07'S, 168°57.60'E, 795–852 m, 26 October 2003: 2 M 4.8–5.0 mm (MNHN-IU-2014-13750).—Stn DW2070 , 25°22.97'S, 168°57.12'E, 630–1150 m, 26 October 2003: 1 F 4.3 mm (MNHN-IU-2014-13758).—Stn DW2075 , 25°23.12'S, 168°20.07'E, 650–1000 m, 27 October 2003: 1 ov. F 3.7 mm (MNHN-IU-2014-13751).—Stn DW2084 , 24°52.00'S, 168°22.00'E, 586–730 m, 28 October 2003: 12 M 2.8–4.7 mm, 1 ov. F 4.3 mm, 7 F 3.0– 5.1 mm (MNHN-IU-2014-13741).—Stn DW2087 , 24°56.22'S, 168°21.66'E, 518–586 m, 28 October 2003: 1 M 4.5 mm, 1 ov. F 3.9 mm (MNHN-IU-2014-13754).—Stn DW2110 , 23°48.34'S, 168°16.81'E, 493–850 m, 31 October 2003: 3 M 3.7–4.1 mm, 6 ov. F 3.9–4.5 mm (MNHN-

IU-2014-13729).—Stn CP2111, 23°49'S, 168°17'E, 500–1074 m, 31 October 2003: 1 M 4.9 mm, 2 F 3.9–5.6 mm (MNHN-IU-2010-5412).—Stn DW2112, 23°44.44'S, 168°18.40'E, 640–1434 m, 31 October 2003: 13 M 2.5–6.2 mm, 5 F 4.2–5.2mm (MNHN-IU-2014-13752).—Stn DW2113, 23°45.17'S, 168°17.99'E, 888–966 m, 31 October 2003: 1 M 5.2 mm, 1 ov. F 3.3 mm (MNHN-IU-2014-13742).

New Caledonia. EXBODI Stn CP 3893, 22°24'S, 171°47'E, 786–814 m, 19 September 2011: 1 m 7.1 mm (MNHN-IU-2014-13772) .

New Caledonia. KANACONO Stn CP 4667, 22°54'S, 167°17'E, 550– 529 m, 12 August 2016: 1 ov. F 6.0 mm, 1 F 4.5 mm (MNHN-IU-2017-3847).— Stn CP 4692, 23°01'S, 167°33'E, 802– 800 m, 15 August 2016: 3 M 6.8–8.7 mm, 1 F 7.5 mm (MNHN-IU-2017-11507).— Stn DR 4771, 23°03'S, 168°20'E, 900– 220 m, 28 August 2016: 1 M 2.3 mm (MNHN-IU-2017-3970) .

New Caledonia. KANADEEP Stn CP 4963, 21°21'S, 158°00'E, 1000– 978 m, 7 September 2017: 1 M 4.5 mm (MNHN-IU-2017-3627) .

Etymology. From the name Ascanius, Aeneas ’s young son by his first wife Creusa, in the Aeneid. The name is considered a substantive in apposition.

Description. Carapace: 1.2 × as long as broad. Mid-transverse ridge usually uninterrupted, preceded by cervical groove, followed by 4 or 5 interrupted transverse ridges. Lateral margins slightly convex, with 3–6 spines: first spine anterolateral, well-developed; small spine on hepatic margin; 1 or 2 spines on anterior branchial margin, and 0–2 spines on posterior branchial margin, last spine, if present, very small. Rostrum horizontal, dorsally concave, 1.4–1.5 × as long as broad, length 0.4 × and breadth 0.3 × that of carapace; lateral margin with 4 or 5 teeth, 1 or 2 proximal spines well-developed, others rudimentary and decreasing in size distally.

Sternum: Sternite 3 broad, 3.4–3.5 × as wide as long, anterolaterally produced, anterior margin with shallow minute median notch flanked by 2 low and smooth lobes. Sternite 4 narrowly contiguous to sternite 3; surface depressed in midline, smooth; greatest width 2.5 × that of sternite 3, twice 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 0.6 × rostrum width, as wide as eyestalk.

Antennule: Article 1 with distomesial angle unarmed or with minute spine; lateral margin smooth along distal part.

Antenna: Article 1 with strong distomesial spine nearly reaching end of article 2; article 2 with strong distomesial spine, longer than distolateral and overreaching 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, extensor margin with well-developed distal spine.

P1: 2.8–3.4 (males), 2.3–2.4 (females) × carapace length, with numerous short setose striae, and uniramous setae scattered on merus to dactylus. Merus slightly longer than carapace, 1.8 × as long as carpus, with strong mesial and distal spines, and some scattered dorsal spines. Carpus 0.7 as long as palm, 1.8 × as long as broad, dorsal surface with scattered spines, mesial margins with 3 strong spines, lateral margin unarmed. Palm, 1.8 × as long as broad, mesial and lateral margins with spines in irregular longitudinal rows, dorsal surface unarmed. Fingers as long as or slightly shorter than palm; fixed finger with 2 proximal lateral spines; movable finger with proximal mesial spine.

P2–4: Slender, somewhat compressed laterally, with short setiferous striae on dorsal surface, with sparse long and thick setae on ischium to dactylus. Meri successively shorter posteriorly (P3 merus 0.6 × length of P2 merus, P4 merus 0.8 × length of P3 merus). P2 merus 0.8 × carapace length, 5.6 × as long as broad, as long as P2 propodus; P3 merus 4.6 × as long as broad, as long as P3 propodus, P4 merus 3.7 × as long as broad, as long as P3 propodus; extensor margins with row of 7 or 8 proximally diminishing spines on P2–3, 4 or 5 minute spines on P4; lateral surface unarmed; flexor margin with 1 well-developed distal spine proximally followed by several additional projecting scales. Carpi with 4 or 5 spines on extensor margin on P2–3, unarmed on P4, flexor margin with small distal spine. Propodi 7.6–9.6 × as long as broad on P2–4, flexor margin with 5 movable spinules. Dactyli 0.4–0.5 × 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 equidistant between base of distal claw and penultimate tooth.

Colour in life. Unknown.

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

Distribution. New Zealand (K. Schnabel, personal communication), New Caledonia, and Hunter and Mathew Islands on bank of sponges from 220 to 1434 m.

Remarks. Leiogalathea ascanius belongs to the group of species having the hepatic margin of the carapace armed with one spine. The closest relatives are L. agassizii from the Caribbean Sea and L. aeneas from eastern Atlantic. These species differ only in the number of spines along the flexor margin of the P2–4 dactyli (7 or 8 in L. agassizii and 8 in L. aeneas , 9 or 10 in L. ascanius ). Furthermore the P2 dactylus is 0.5–0.6 × the length of the P2 propodus in L. agassizii , whereas the P2 dactylus is ± than half (0.4–0.5) length of the P2 propodus in L. ascanius . The P2–4 propodi are slender (8–10 × as long as broad) in L. ascanius , whereas are stout in L. aeneas (less than 6 × as long as broad). Leiogalathea ascanius and L. agassizii are very different genetically, with divergences of 13.1% in COI and 5.5% in 16S.

Figures

FIGURE 6. Leiogalathea ascanius n. sp., A, C–I, holotype, M 5.9 mm, New Caledonia (MNHN-IU-2013-17425); B, paratype, M 7.1 mm, New Caledonia (MNHN-IU-2014-13772). A, carapace and abdomen, dorsal view. B, carapace, right profile, dorsal view. C, sternites 3–4. D, cephalic region, showing antennular and antennal peduncles, ventral view. E, right Mxp3 ischium and merus, lateral view. F, right P1, dorsal view. G, right P2, lateral view. H, dactylus of right P2, lateral view. I, right P3, lateral view. Scales: A, B, F, G, I = 1.0 mm; C–E, H = 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.