Decapoda - Brachyura - Xanthidae - Xanthias

Xanthias maculatus Sakai, 1961



World Distribution
Serène (1984 : 198). Japon seulement pour la forme type à Afrique orientale, Kenya, si la forme attribuée à 'Xanthias aff. maculatus' correspond à l'espèce de Sakai. Comprend Mayotte premier signalement.
15-85 m in Sakai, Japan.

Environnement : Marine - Substrat/Association : Hard bottom (rock and rubbles)

Vertical range : Shallow-waters (0-100 m) - Min-Max observed: 0-30 m

Mayotte data
Xanthias maculatus Sakai, 1961 s.l.
Material examined — Mayotte KUW 2009, st. 23, Choizil Pass, "Patate à Teddy", 15-30 m, 1 F 3.7 x 6.5 mm, 1 M 5.0 x 7.5 mm (photos, remain of color still present in July 2011), MNHN-IU-2009-2633; st. 23, id. 1 F 5.9 x 8.7 mm, 1 juv. 4.1 x 6.1 mm (almost no remains of coloration in July 2011), MNHN-IU-2009-2634; st. 25, Islet M'tzamboro, south, 15-20 m, 1 juv. 3.1 x 4.7 mm (compared with sp. at st. 23, July 2011), MNHN-IU-2009-2632.
Remarks — The specimens from Mayotte are ocellated Xanthias with characters intermediate between the two species currently known, revised in Mendoza (2013): Xanthias maculatus Sakai, 1961 and Xanthias joanneae Mendoza, 2013. With X. joanneae they share: a) great number of ocelli on the carapace 31-33 (at least 40 in X. joanneae vs about 14 in X. maculatus); b) ambulatory legs with broader and stouter meri, ratio of the width of the P5 merus to carapace length being about 0.21 (0.22 in X. joanneae vs 0.17 in X. maculatus). With X. maculatus they share: a) dorsal carapace region well demarcated, similar to holtoype illustrated in Mendoza (2013, fig. 5A) (not well demarcated in X. joanneae); b) teeth of anterolateral margin of carapace with acute apices (rounded apices in X. joanneae (compare Mendoza, 2013: fig. 3A, 5A); c) external surface of the palm of the chelipeds with longitudinal ridges (no ridges in X. joanneae. Serène (1984) has attributed several specimens from Kenya and 1 specimen from Vietnam to X. aff. maculatus because of teeth of anterolateral margin of carapace with rounded apices, merus of P5 stouter than in X. maculatus, and fewer number of ocelli on carapace (20 for Vietnamese specimen). He has suggested large intraspecific variations within X. maculatus depending on collecting sites. On the other side, Mendoza (2013) has speculated that the Kenya specimens of Serène (1984) comprise a distinct species from either X. maculatus or X. joanneae. Clearly, the intermediate characters observed in the present collection from Mayotte indicate that X. maculatus s.l. is in need of revision to decide if a single species is involved, with large regional variations, or if more than two species should be considered in this group of ocellated Xanthias.
Geographic and depht ranges (for ocellated Xanthias: X. maculatus, X. joanneae) — IWP, Kenya, Mayotte (this work) to Philippines, Japan; subtidal to 85-110 m.

Comment(s) on data
Mendoza (2013: 374, Zootaxa) has recently described Xanthias joanneae, a species very similar to X. maculatus. By the presence of lateral ridges on outer face of chelae, our specimens from Mayotte are related to Xanthias maculatus while by the number of spots (about 30) on dorsal face of the carapace they are closer to X. joanneae. Although the Mayotte specimens are kept here under X. maculatus, It is possible that they are conspecific with Xanthias aff. maculatus from Kenya in Serène (1984) with this comment by Mendoza (2013: 383) - It is very likely that the Kenyan specimens comprise a distinct species from either X. maculatus or X. joanneae sp. nov. -

References : PDF list, 214 pp (1.4 Mo)

This species in Worms Database