Eiconaxius caribbaeus ( Faxon, 1896 )

Poore, Gary C. B., 2018, Caribbean species of Eiconaxius (Decapoda: Axiidea: Axiidae), Zootaxa 4524 (1), pp. 139-146 : 142-145

Eiconaxius caribbaeus ( Faxon, 1896)

( Figs 3 , 4 )

Iconaxius caribbaeus Faxon, 1896: 155 , pl. 1 figs 1–4.— Balss 1925: 209 (list).

Eiconaxius communis Bouvier, 1905: 803 .

Axius (Eiconaxius) communis De Man, 1925: 4 (list), 17 (key).

Eiconaxius rotundifrons Bouvier, 1905: 803 . Syn. nov.

Axius (Eiconaxius) caribbaeus carinatus Bouvier, 1925: 465 , pl. 9 fig. 3.— Schmitt 1935: 191 –192, fig. 52. Syn. nov.

Axius (Eiconaxius) caribbaeus .— Bouvier 1925: 461 –463, pl. 7 fig. 6.— De Man 1925: 4 (list), 16 (key).

Axius (Eiconaxius) caribbaeus rotundifrons .— Bouvier 1925: 463 –464, figs 23–25, pl. 10 figs 3, 4.

Iconaxius communis .— Balss 1925: 210.

Axius (Eiconaxius) rotundifrons .— De Man 1925: 4 (list), 17 (key).— Sakai 2011: 285

Iconaxius rotundifrons .— Balss 1925: 210.

Eiconaxius carribaeus .— Sakai & de Saint Laurent 1989: 19 (misspelling).

Eiconaxius carinatus .— Sakai & de Saint Laurent 1989: 23.— Sakai 2011: 276.— Komai & Tsuchida 2012: 37 (list).

Eiconaxius rotundifrons .— Sakai & de Saint Laurent 1989: 21 –22, fig. 6.— Felder et al. 2009: 1963 (records).— Sakai 2011: 276.— Komai & Tsuchida 2012: 37 (list).

Eiconaxius caribbaeus .— Kensley,1996: 475 (list).— Felder et al. 2009: 1963 (records).— Sakai 2011: 275.— Komai & Tsuchida 2012: 37 (list).

Type material. Eiconaxius communis Bouvier, 1905 . Syntypes. Guadeloupe, 15.9°N, 61.6°W, 275 m (Blake stn 166), MCZ CRU-11954 (7), MNHN IU-2014-7157 (Th178) (1), MNHN IU-2014-7159 (Th180) (2) . Grenada, Milligan Key , 12.1°N, 61.8°W, 227 m (Blake stn 259), MNHN IU-2014-7160 (Th181) (2) . Grenada, St Vincent , off Milligan Key, 13.1°N, 61.1°W, 227 m (Blake stn 269), MCZ CRU-11955 (3 males, 1 female) . Barbados, 13.0°N, 59.6°W, 225 m (Blake stn 297), MCZ CRU-11956 (1 male, 2 females), MNHN IU-2014-7158 (Th179) (ovigerous female) . Barbados, 13.1°N, 59.6°W, 256 m (Blake stn 299), MCZ CRU-11957 (1), MNHN IU-2014-7156 (Th177) (1) .

Eiconaxius rotundifrons Bouvier, 1905 . Syntypes. Martinique, 14.4°N, 60.9°W, 346 m (Blake stn 209), MCZ CRU-11951 (ovigerous female). St Lucia, 13.8°N, 61.1°W, 300 m (Blake stn 218), MCZ CRU-11952 (male) . Barbados, 12.9°N, 59.6°W, 527 m (Blake stn 281), MCZ CRU-11953 (female, male lost) . Barbados, 13.1°N, 59.7°W, 432 m (Blake stn 283), MCZ CRU-11967 (2 ovigerous females) . Saint Lucia, 281 m (Blake stn 216), MNHN IU-2014-5069 (4 males, 4 ovigerous females)

Axius (Eiconaxius) caribbaeus carinatus Bouvier, 1925 . Syntypes. St Croix, off Mount Eagle, 17.8°N, 64.8°W, 399 m (Blake stn 139), MCZ CRU-11968 (1). Montana, Montserrat, 16.7°N, 62.2°W, 545 m (Blake stn 154), MNHN IU-2014-7161 (Th182) (female). Grenada, Milligan Key, 12.1°N, 61.8°W, 291 m (Blake stn 259), MCZ CRU-11958 (female).

Non-type material. From Blake stations. Eiconaxius caribbaeus ( Faxon, 1896) . Guadeloupe, 15.9°N, 61.6°W, 275 m (Blake stn 166), MCZ CRU-74395 (1), MCZ CRU-19408 (male) . St. Lucia, 13.8°N, 61.1°W, 300 m (Blake stn 218), MCZ CRU-126745 (1) . Barbados, 13.2°N, 51.9°W, 384 m (Blake stn 291), MCZ CRU-19409 (1).

Other material. Cuba, off Matanzas, 420 m (Harvard-Havana Expedition 1938 stn 2999) (MNHN IU-2017- 1738, MCZ donation (female non-type).

Guadeloupe. KARUBENTHOS 2015 stations. N of Grande-Terre , 16°34'N, 61°37'W, 426–441 m (stn DW4518 ), IU-2013-18871 (male, 5.6 mm) . 16°38'N, 61°31'W, 320–338 m (stn DW4538 ), IU- 2016-2319 (ovigerous female, 5.6 mm) . 16°37'N, 61°31'W, 432–482 m (stn DW4550 ), IU- 2016-2411 (3 males, 3.6–3.8 mm; 7 females, 4.5–4.8 mm; ovigerous female, 5.8 mm), ( NMV J71645 ) (male, 5.1 mm; female, 5.7 mm; 2 ovigerous females, 5.7–6.0 mm). W of Marie-Galante , 15°48'N, 61°28'W, 378–432 m (stn DW4633 ), IU- 2016-2642 (female, 5.4 mm). S of Marie-Galante , 15°48'N, 61°20'W, 485–496 m (stn DW4639 ), IU- 2016-2903 (2 males, 4.2, 6.5 mm). E of La Désirade , 16°20'N, 60°55'W, 389–413 m (stn DW4573 ), IU-2016-8309 (male, 3.6 mm; female, 4.5 mm; 4 ovigerous females, 4.3–6.3 mm) . 16°22'N, 60°54'W, 140–340 m (stn DW4574 ), IU-2016-8353 (female, 4.0 mm) . 16°21'N, 60°56'W, 370 m (stn DW4554 ), IU-2016-8361 (4 males, 4.5–6.4 mm; female, 5.7 mm; 5 ovigerous females, 4.4–6.1 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; lateral margins smooth or denticulate. Major cheliped fingers about half as long as upper margin of palm; fixed finger cutting edge with broad blade over proximal half, irregular beyond; dactylus cutting edge with basal molar, notch and straight beyond. Minor cheliped palm upper margin as long as greatest width; distolateral margin with prominent triangular toothed lobe at base of dactylus; fingers almost as long to longer than upper margin of palm. Uropod endopod anterolateral apex acute, with 1 or few small teeth.

Distribution. USA, Cuba, Mexico, Virgin Islands, Monserrat, Martinique, Dominica, Grenada, Guadeloupe, Saint Lucia, Barbados; Caribbean Sea; Straits of Florida; Gulf of Mexico; 140–545 m depth.

Remarks. Faxon (1896) designated the specimen from Blake stn 283 as the “type” (holotype) of Iconaxius caribbaeus but this is lost. He also listed one each from Blake stns 166 and 232 plus three from Blake stn 241. One specimen from Blake stn 166 remains in the MCZ (CRU-74395), possibly the “femelle qui a servi de type pour la description précédente” by Bouvier (1925). Bouvier listed other material from Blake stn 166 (3 males, 5 females, plus several), stn 218 (2), stn 259 (1 male, 2 females), stn 269 (1 ovigerous female, 3 males), stn 291 (1), stn 290 (2 males, 1 female), stn 297 (2 ovigerous females) and stn 299 (2 males, 1 female) but only two of these remain in the MCZ. Bouvier (1925) treated Eiconaxius communis Bouvier, 1905 as a junior synonym of Axius (Eiconaxius) caribbaeus without specifying its types or type localities. Five lots bearing this name, presumably in Bouvier’s hand, from some of the stations listed under A. (E.) caribbaeus by Bouvier (1925) remain in the MNHN and are treated as syntypes of E. communis . The male of Eiconaxius rotundifrons from Blake stn 241 listed by Bouvier (1925) is lost. Bouvier (1925) listed syntypes of Axius (Eiconaxius) caribbaeus carinatus from four Blake stations: stn 139 (1 female) and stn 259 (1 female), now at MCZ, stn 154 (1 female), now at MNHN, and stn 232 (1 male) now lost.

Bouvier (1905, 1925) distinguished his species and varieties relying on the prominence of the denticulation of the rostral margin and the cheliped merus margin, and the degree of carination of the major cheliped. These are subtle differences and in this large sample intermediate states were common. None of Bouvier’s species or varieties are recognised here. The fixed finger of the major cheliped of Eiconaxius caribbaeus consistently has a broad concave blade, slightly more elevated distally, over its proximal half. A blunt proximal tooth opposes it on the dactylus. These can be seen in Faxon’s (1896) figure 3 and in Bouvier’s (1925) figure 3 of E. caribbaeus rotundifrons . The median carina bifurcates and disappears quickly on the gastric region.

The species is the mostly commonly occurring species of the genus in the Caribbean and that with the shallowest depth range. There is a single record from the Gulf of Mexico as E. rotundifrons (see Felder et al. 2009).

Figures

FIGURE 3. Eiconaxius caribbaeus (Faxon, 1896). Syntype of Axius (Eiconaxius) caribbaeus carinatus Bouvier, 1925, IU- 2014-7161. A, rostrum, anterior gastric region, dorsal view. B, major cheliped, lateral view. C, major cheliped, fingers, mesial view. Syntype of Eiconaxius rotundifrons Bouvier, 1905, IU-2014-5069. D, minor cheliped, lateral view. E, minor cheliped fingers, mesial view. Scale bar = 1 mm.

FIGURE 4. Distribution of four species of Eiconaxius throughout the Gulf of Mexico and Caribbean Sea. E. agassizi (10 records); E. antillensis (7 records); E. borradailei (7 records); E. caribbaeus (25 records).