Tweedieia odhneri ( Gordon, 1934 )

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 : 12

Tweedieia odhneri ( Gordon, 1934)

[Jn: Oome-ougigani]

( Fig. 3H)

Material examined. Chichi-jima Is.—Nishijima I., 1 8 (NSMT-Cr 31545; cb 7.7×cl 5.6 mm), 29-VI-1976, M. Takeda leg.

Haha-jima Is.—Mei-jima I., west coast, 10 m, 1 juv. (NSMT-Cr 31546; cb 4.4×cl 3.3 mm), 11-VII-2016, H. Komatsu leg.; Imoto-jima I., diving site Blue ribbon (26°34′03″N, 142°12′48″E), 12–14 m,1 8 (NSMT-Cr 31547; cb 10.8×cl 7.9 mm), 1 8 (NSMT-Cr 31548; cb 11.5×cl 8.4 mm), 14-VII-2016, H. Komatsu leg.

Remarks. The genus Tweedieia Ward, 1935 , was deeply studied by Lasley et al. (2022) and Maenosono (2022b) who recognized two species, T. laysani ( Rathbun, 1906) and T. odhneri ( Gordon, 1934) . As well described in the original descriptions of both species ( Rathbun, 1906; Gordon, 1934), these two species are close to each other in the shape and areolation of the carapace dorsal surface, but differ mainly in the carapace shape (ovate and narrower in T. odhneri ), the carapace anterolateral teeth (triangular and low, with wide and shallow clefts in T. odhneri ), the frontal median notch (broad in T. odhneri ), the cheliped carpus (with broad and transverse furrow on outer margin in T. odhneri ), the movable finger (strongly curved distally in T. odhneri ), and the palm (nodular granules on outer surface in T. odhneri ). Maenosono (2022b) applied these and some additional characters to the specimens from the Ryukyu Islands and confirmed the occurrence of the two species. Some characters seem to be variable individually, but at least the ovate and narrower carapace and the granulation of the palm outer surface are effec- tive to identify the Ogasawaran specimens as T. odhneri .

Distribution. Lasley et al. (2022) concluded that T. laysani is only known from the Hawaiian Islands, while T. odhneri is widely distributed in the Indo-West Pacific including the Hawaiian Islands. In Japanese waters, two species are known from the Ryukyu Islands as reported by Maenosono (2022b). It is shortly noted here about the specimen identified as T. laysani from the unrecorded locality in the Ryukyu Islands by Nagai and Nomura (1988). The present authors examined just that specimen preserved in the Wakayama Prefectural Museum and re-identified it as Serenius kuekenthali (De Man, 1902) . The data of the specimen is as follows: Nago, Okinawa I., Ryukyu Is., 1 8 (WPM-No. 852; cb 13.0 mm, cl 8.6 mm) from coral block of Pocillopora entangled with gill-net for lobster; Apr. 1973; S. Nagai leg.