Eiconaxius antillensis Bouvier, 1905

Poore, Gary C. B. & Dworschak, Peter C., 2018, The Eiconaxius cristagalli species complex (Decapoda, Axiidea, Axiidae), Memoirs of Museum Victoria 77, pp. 105-120 : 106-108

Eiconaxius antillensis Bouvier, 1905

Figures 1 , 2

Eiconaxius crista-galli var. antillensis Bouvier, 1905: 803 .

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

Axius (Eiconaxius) crista-galli antillensis . – Bouvier, 1925: 456– 458, pl. 8 fig. 3, pl. 9 fig. 1. – De Man, 1925: 4, 33.

Eiconaxius antillensis . – Sakai and de Saint Laurent, 1989: 21. – Kensley, 1996: 475. – Sakai, 2011: 273. – Felder et al. 2009: 1063.

Eiconaxius?antillensis . – Poupin and Corbari, 2016: 32, fig. 8a

(photograph).

Material examined. Syntypes. Off Montana , Monserrat , 16.7°N, 62.2°W, 545 m, Blake stn 154, MCZ CRU-11946 (male, 6.1 mm). Barbados, 12.9°N, 59.6°W, 527 m, Blake stn 281, MCZ CRU-11947 (ovigerous female, 6.7 mm) .

Guadeloupe, N of Grande Terre , 16°37'N, 61°31'W, 432–482 m (KARUBENTHOS stn DW4550), MNHN IU-2016-8456 (ovigerous female, 6.3 mm), MNHN IU-2018-106 (3 females, 5.8–7.1 mm), MNHN IU-2013-18924 (2 males, 4.3, 6.7 mm), NMV J71649 (ovigerous female, 7.6 mm). NMV J71655 (4 females, 5.3–7.3 mm) .

Caribbean Sea, Mexico, NE of Yucatan, 22.72°N, 86.22°W, 1030 m, ( Cruise : 65A9-21) USNM 1014172 (1 specimen, det. B. Kensley, examined by C.C. Tudge). E of Guadeloupe, 16.55°N, 61.62°W, 466– 585 m (Pillsbury stn P994), USNM 1081088 (3 specimens, examined by C.C. Tudge) .

Diagnosis. Rostrum tapering more over distal third than proximal, with rounded apex in adult (acute in juvenile), 1.2– 1.3 times as long as wide. Median carina erect, with clear dentition (10–20 teeth); lateral gastric carina with hiatus between lateral rostral margin and short gastric section, visible only posterior to confluence of submedian carinae. Major cheliped, palm wider distally than at midpoint, distolateral margin with sharp tooth at base of finger; fixed finger about 3/4 length of upper margin of palm, cutting edge with basal notch, blade-like proximal half, and distal concavity; dactylus cutting edge with blunt tooth at midpoint, denticulate beyond. Minor cheliped, palm upper margin as long as greatest width; distolateral margin with prominent triangular toothed lobe at base of dactylus; fixed finger cutting edge weakly crenellate, with excavated distal quarter.

Distribution. Monserrat, Barbados, Guadeloupe, Caribbean Sea, W Atlantic, S. of Jamaica; 432–1030 m.

Remarks. Bouvier (1905) listed no specimens when he erected his new variety but mentioned a male and a female from two stations later ( Bouvier, 1925). We treat them as syntypes. The male syntype differs significantly from all other specimens identified by us and by others in the past, including the second specimen identified by Bouvier (1925). Notably the distolateral margin of the palm of the major cheliped bears a high and sharp tooth ( Fig. 1f ) whereas in all other material there is a blunt asymmetrical tooth ( Figs 2h, i are typical; broken in Fig. 2c ). The notch below this tooth is less pronounced in the male syntype than in other specimens. These differences appear not size-related – this specimen is within the size range of the other material.

Eiconaxius antillensis is the only species of this group in the Atlantic but is confined to the Caribbean or nearby, an area with biogeographic affinities to the Indo-West Pacific where the remainder live. The species is similar to E. cristagalli , the Eastern Pacific species, in the dentition of the propodus and fixed finger of the major cheliped, both with a deep notch in the gape and a distal concavity on the finger. It differs in having a narrow, parallel-sided rostrum with numerous teeth on the median carina (cf. rostrum triangular, tapering, median carina with six or seven teeth in Faxon’s and Kensley’s accounts of E. cristagalli ). Kensley (1996: fig. 7F) showed the distolateral margin of the minor cheliped of E. cristagalli with two teeth; only one is present on these specimens of E. antillensis . The lateral carina has a clear hiatus between the posterior extension of the rostral margin and the ridge level with the submedian carina, as in E. gololobovi sp. nov.; Kensley (1996) noted no such hiatus in E. cristagalli .

Figures

Figure 1. Eiconaxius antillensis Bouvier, 1905, Syntype, MCZ 11964 (male, 6.1 mm) – a, carapace, pleon, lateral. b, anterior carapace, antenna, antennule, dorsal view. c, rostrum, anterior median carina, left oblique view. d, telson, right uropod. e, f, major cheliped (left), mesial, lateral views. g, h, minor cheliped (right), mesial, lateral views. Scale bar = 1 mm.

Figure 2. Eiconaxius antillensis Bouvier, 1905, IU-2016-8456 (ovigerous female, 6.3 mm) – a, b, anterior carapace, antenna, antennules, lateral, dorsal views. c, d, major cheliped (left), lateral, mesial views. e, f, minor cheliped (right), lateral, mesial views. g, h, major cheliped (left), distal propodus, dactylus, lateral, mesial views. NMV J71649 (ovigerous female, 7.6 mm) – i, major cheliped (left), lateral view. Scale bars = 1 mm.