Eiconaxius indicus (De Man, 1907 )

Poore, Gary C. B. & Dworschak, Peter C., 2018, The Eiconaxius cristagalli species complex (Decapoda, Axiidea, Axiidae), Memoirs of Museum Victoria 77, pp. 105-120 : 116-118

Eiconaxius indicus (De Man, 1907)

Figures 9 , 10

Iconaxius crista-galli var. indica De Man, 1907: 128–129 .

Iconaxius cristagalli var. indica . – Balss, 1925: 210.

Axius (Eiconaxius) crista-galli var. indica . – De Man, 1925: 4, 15, 31, pl. 2 fig 3.

Eiconaxius indica . – Sakai and de Saint Laurent, 1989: 22.

Eiconaxius indicus . – Kensley, 1996: 475. – Sakai, 2011: 279 (partim), fig. 52.

Not Eiconaxius indicus . – Sakai and Ohta, 2005: 73–77, figs 3–5. – Tsang et al., 2008: 363, fig. 2 (= Eiconaxius dongshaensis sp. nov.)

Material examined. Holotype. Indonesia, E of Palau Kei Besar (Great Kei I.), 5°54'S, 132°56'7"E, 984 m ( Siboga stn 267), ZMA102465 (ovigerous female, 10.6 mm) – photographed by C.H.J.M. Fransen, figured by Sakai (2011: fig. 52).

Vanuatu. Between Malekula and Ambrym islands , 16°30.7'S, 167°55.5'E, 550–565 m ( BOA1 stn CP2468), MNHN IU-2014-10474 (male, 9.1 mm). Between Malekula and Epi islands, 16°38.28'S, 167°58.38'E, 586–646 m ( BOA 0 stn CP2307), MNHN IU-2014-7149 – 7152 (2 ovigerous females, 10.8, 11.0 mm; 2 males, 9.0, 10.8 mm)

Solomon Islands, NW of San Cristobal, 09°56'S, 161°04'E, 418– 432 m (SALOMON 1 stn DW1826), MNHN IU-2016-8020 (ovigerous female, 12.1 mm) .

New Caledonia, BATHUS 3 stations. Loyalty Ridge , seamount K, 24°43'S, 170°07'E, 750–760 m (stn DW778), NMV J71631 (4 males, 6.1–9.8 mm; 3 females, 7.6–9.0 mm); seamount K, 24°44'S, 170°08'E, 770–830 m (stn DW776), MNHN IU-2016-8022 (2 females, 6.1, 9.3 mm); seamount D, 23°35'S, 169°37'E, 655 m (stn DW800), MNHN IU-2016-8023 (female, 10.0 mm). S of Ile des Pins, 23°09'S, 167°11'E, 650– 680 m ( BIOCAL stn DW36), MNHN IU-2016-8021 (female, 7.8 mm) .

Diagnosis. Rostrum tapering more over distal third than proximal, with rounded apex in adult (acute in juvenile), 1.5–2.0 times as long as wide. Median carina erect, with clear dentition; sublateral gastric carinae present, diverging widely from base of median carina; lateral gastric carina with hiatus between lateral rostral margin and short gastric section, visible only posterior to confluence of submedian carinae. Major cheliped, palm upper margin smooth, carinate, or denticulate; lateral and mesial faces tuberculate near base of fingers; distolateral margin with 1 or 2 teeth in gape but without a deep notch; fixed finger about half as long as upper margin of palm, cutting edge blade-like, with proximal notch and distal concavity; dactylus cutting edge with basal molar, notch and straight beyond. Minor cheliped, palm upper margin as long as greatest width; distolateral margin with sharp spine at base of dactylus; lateral and mesial faces tuberculate near base of fingers; fingers almost as long to longer than upper margin of palm.

Description. (based on MNHN IU- 2014-10474, male, 9.1 mm). Carapace smooth. Rostrum 0.2 carapace length, concave dorsally, tapering evenly to acute tip, twice as long as wide at base, with c. 7 teeth on lateral margins, depressed below level of median carina, separated from lateral carinae by long hiatus, without ventral tooth. Lateral gastric carina visible only posterior to confluence of submedian carinae, short, unarmed. Submedian gastric carina smooth, together curved and converging on median carina. Median carina prominent, erect, reaching two-thirds along rostrum, with c. 12 uneven teeth. Pleuron 1 posteroventrally rounded; pleura 2, 3 posteroventrally produced, acute; pleura 4, 5 less produced, posteroventrally acute; pleura 3, 5 with anteroventral tooth; pleuron 6 with rounded posteroventral angle; pleonite 6 dorsal posterior margin denticulate.

Eyestalk third length of rostrum; cornea unpigmented. Antennular peduncle reaching to midpoint of antennal article 4; article 1 unarmed. Antennal article 1 unarmed; article 2 without distomesial spine, stylocerite an elongate triangular blade, reaching just beyond midpoint of article 4; scaphocerite a vertical blade, reaching midpoint of article 5; article 3 lower margin with mesial tooth; article 5 about half length of article 4.

Major cheliped ischium lower margin produced as spinose ridge; merus lower margin finely denticulate, upper margin with minute tooth; carpus lower margin with 1 distal tooth; propodus upper margin carinate, denticulate, toothed distally, length 1.25 greatest height, lower margin smooth, lateral face tuberculate on lower palm, mesial face tuberculate at base of fixed finger; fixed finger half as long as upper palm, cutting edge concave with proximal and subdistal obtuse teeth, with longitudinal mesial ridge; distolateral margin of palm denticulate, with blunt tooth above circular gape; distomesial margin of palm denticulate, angled tooth near gape; dactylus distally curved, cutting edge with blunt proximal tooth, otherwise straight, smooth.

Minor cheliped shorter and more slender than major, palm 0.9 times height of major palm; ischium lower margin with 2 subdistal spines; merus lower margin denticulate, most distal spine-like; carpus lower margin with 1 distal tooth; propodus dilating, upper margin carinate, denticulate, 0.95 times greatest height, lower margin smooth, lateral and mesial faces tuberculate at base of fixed finger; fixed finger as long as upper palm, cutting edge denticulate, with longitudinal mesial and lateral ridges; distolateral margin of palm oblique, with sharp spine in gape; distomesial margin of palm oblique, with spine in gape; dactylus almost straight, upper margin carinate, cutting edge smooth, with subdistal notch.

Figures

Figure 9. Eiconaxius indicus (De Man, 1907). MNHN IU-2014-10474 (male, 9.1 mm) – a, carapace, pleon, lateral. b, anterior carapace, antenna, lateral. c, anterior carapace, antennule, antenna, dorsal. d, pleomere 6, telson, right uropod. e, f, right minor cheliped, lateral and mesial. g, h, left major cheliped, lateral and mesial. i, pereopod 2. j, k, left pereopod 3, detail of dactylus. l, left pereopod 5, detail of dactylus. Scale = 2 mm (except b, c, k, l).

Figure 10. Eiconaxius indicus (De Man, 1907). MNHN IU-2016-8020 (ovigerous female, 12.1 mm) – a, anterior carapace, antenna. b, telson, right uropod. c, d, left major cheliped, lateral and mesial views. e, f, left minor cheliped, lateral and mesial views. MNHN IU-2014-7149 (ovigerous female, 11.0 mm) – g, anterior carapace, antenna. MNHN IU-2014-7151 (male, 9.0 mm) – h, right major cheliped fingers, lateral view. NMV J71631 – telsons of 4 individuals: i, male, 9.8 mm; j, male, 7.3 mm; k, ovigerous female, 9.0 mm; l, female, 7.6 mm. Scale = 2 mm