Garthiella aberrans ( Rathbun, 1906 )

Alrasheedi, Sami M, Alrashdi, Mousa N, Alhumaidan, Lama S, Alkhdairi, Ahmad, Alzweihary, Ali M, Alhussaini, Omar M, Alharbi, Lama S, Albalawi, Amirah N, Almutairi, Turki F, Alharbi, Osama A G & Bashal, Afaf A M, 2024, Crabs of the Families Tetraliidae, Trapeziidae and Xanthidae (Crustacea: Decapoda: Brachyura) new to the Ogasawara Islands, Japan, Bulletin of the National Museum of Nature and Science. Series A, Zoology 50 (1), pp. 1-17 : 5-6

Garthiella aberrans ( Rathbun, 1906)

[New Jn: Gahsu-toge-ougigani]

( Fig. 2F)

Material examined. Haha-jima Is. — Mukohjima I., diving site Maguro-ana (26°36′37″N, 142°07′46″E), 1 young 8 (NSMT-Cr 31522; cb 7.5×cl 5.2 mm), 5-VII-2015, H. Komatsu leg. ; Mei-jima I., west coast (26°34′08″N, 142°13′40″E), 10m, 2 88 (NSMT-Cr 31523; cb 8.2×cl 5.6 mm, cb 10.3×cl 6.4 mm), 11-VII-2016, H. Komatsu leg. ; Hira-shima I., diving site Sasao-ne (26°35′07″N, 142°09′45″E), 1 8 (NSMT-Cr 31524; cb 8.5×cl 5.6 mm), 3-VII-2015, H. Komatsu leg. ; Imoto-jima I., diving site Blue ribbon (26°34′03″N, 142°12′48″E), 15–17 m, 1 juv. (NSMT-Cr 31525; cb 4.8×cl 3.6 mm), 11-VII-2016, H. Komatsu leg. ; Haha-jima I., diving site Uentoro (26°39′28″N, 142°10′35″E), 12–20 m,1 8 (cb 7.8×cl 5.7 mm), 1 juv. (cb 3.5×cb 4.9 mm), NSMT-Cr 31526, 12-VII-2016, H. Komatsu leg.

Remarks. The carapace dorsal areolation and anterolateral armature of this species are most close to those of Epiactaea nodulosa (White, 1847) (cf. Serène, 1984) and generally to some species of the genera Actaea and Pilodius . The peculiarity of the genus Garthiella erected by Titgen (1986) to accommodate Chlorodopsis aberrans Rathbun, 1906 , has been already noticed and named this species as aberrans by Rathbun (1906). It is sure that the fingers of both chelae are sharply pointed, differing from the hollowed tips in the species of the related genera.

Rathbun (1906), Edmondson (1962), and Serène and Nguyen (1959) dealt with this species with figures as Chlorodopsis aberrans, Serène (1984) took this species in the key to the genus Pilodius , and Mendoza and Manuel-Santos (2012) explained and illustrated in detail as Garthiera based on the holotype from northwestern Hawaiian Islands and several additional specimens from French Polynesia. The specimens from the Ogasawara Islands agree well with the figures and photographs in the literature, having the carapace and chelipeds roughened with sharp tubercles, the carapace anterolateral margin armed with four sharp spiniform teeth weakly covered forwards, and the anterior margins of the ambulatory segments fringed with a line of the equidistant spiniform teeth.

The second species of the genus Garthella , G. sikatuna reported by Mendoza and Manuel-Santos (2012), from the Philippines, is distinguished from G. aberrans most readily by the less coarse granulation of the carapace and chelipeds among the differences mentioned in the original paper.

Distribution. Hitherto been known from the Hawaiian Islands and French Polynesia. This species is new to the carcinological fauna of Japanese waters.