Thalamita sima H. Milne Edwards, 1834

Manikandan, K, Megalaa, N, Valliappan, Subramanian, Nandini, K, Rani, Lourdu V, Dakshinamurthi, Senthil & Nagappan, Nagappan, 2022, Crabs (Crustacea, Decapoda) from the Seas of East and Southeast Asia Collected by the RV Hakuhō Maru (KH- 72 - 1 Cruise) 3. Sahul Shelf, Bulletin of the National Museum of Nature and Science. Series A, Zoology 48 (2), pp. 35-83 : 65-66

Thalamita sima H. Milne Edwards, 1834

( Fig. 14D–F )

Material examined. RV Hakuhō Maru KH-72-1 cruise, sta. 30, 1 Ə( CB 20.2 mm including lateral teeth×CL 14.0 mm), NSMT-Cr 30738.

Remarks. Thalamita sima is best characterized by the two-lobed front (this report: fig. 14E; Shen, 1934: fig. 17; Sakai, 1939: pl. 51 fig. 3; Barnard, 1950: fig. 33b; Stephenson and Hudson, 1957: pl. 5 fig. 2; Sakai, 1965: pl. 64 fig. 1; Sakai, 1976: pl. 130 fig. 3; Wee and Ng, 1995: fig. 59A), the pilose carapace surface (this report: fig. 14D, F) and the squamiform sculpture of the palm lower surface (this report: fig. 14E; Montgomery, 1931: pl. 29 fig. 2; Shen, 1934: fig. 18a). Of the five anterolateral teeth of the carapace, the fourth is slightly smaller than the others as seen in Fig. 14D of this report. The basal antennal article is armed with a low, smooth, curved crest finely granulated along the margin. Stephensen (1945: fig. 27E), Stephenson and Hudson (1957: fig. 3C), Crosnier (1962: fig. 181), Dai and Yang (1981: fig. 138-1), Wee and Ng (1995: fig. 59D– F) and Apel and Spiridonov (1998: fig. 94) gave fine figures of the G1 with the flared tip, which is close to those of such species as Th. sexlobata Miers, 1886 and Th. picta Stimpson, 1858 , in having the four-lobed front.

Distribution. Widely distributed in the Indo-West Pacific, from Hawaii and Japan to southwards to New Caledonia and Australia, and westwards to South Africa and the Red Sea. In Japan, this species is not uncommon on rocky shores down to 15 m depth, but otherwise there are some records from deeper waters down to 50 m. The bathymetric range is extended down to 115 m in this report.

Figures

Fig. 14.ɹA–C: Thalamita intermedia Miers, Ə (NSMT-Cr 30737; CB 12.7×CL 8.6mm) from sta. 29. Dorsal view (A), right anterolateral teeth (B), and front-orbital margin (C). D–F: Thalamita sima H. Milne Edwards, Ə (NSMT-Cr 30738; CB 20.2×CL 14.0mm)from sta. 30. Dorsal view (D), frontal margin (E), and both chelae (F).