Hyastenus kyusyuensis ( Yokoya, 1933 )

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 : 49

Hyastenus kyusyuensis ( Yokoya, 1933)

( Fig. 6F–H )

Material examined. RV Hakuhō Maru KH-72-1 cruise, sta. 29, 1 Ə ( CB 5.3 mm excluding branchial spines× PCL 8.7 mm), NSMT-Cr 30720; 1Ə (5.1× 8.2mm), 2♀♀ (4.0× 6.5 mm; 4.5× 7.6mm), NSMT-Cr 30721.

Remarks. Hyastenus kyusyuensis had once been recorded frequently from Japan (cf. Sakai, 1976), but the morphological characters were not detailed in the previous studies. Moreover, it is highly possible that the holotype described as Halimus kyusyuensis is no longer extant. Komatsu (2011) recorded many specimens from the Ogasawara Islands and some localities along the Pacific coast of Japan from the Sagami Sea to the East China Sea, including a topotypic male from off the Osumi Islands in the south of Kyushu. The present specimens from the Sahul Shelf shown in the dorsal, ventral and lateral views ( Fig. 6F–H ) share many characters with Komatsu`s H. kyusyuensis , but slightly differ in the apical structure of the G1 represented by Komatsu (2011: fig. 14C–E). This might be referred to individual or ontogenetic variation as suggested by similar changes in several other Hyastenus species ( Ohtsuchi et al., 2020).

Distribution. Recorded geographic range is from Sagami Bay to the East China Sea including the Ogasawara Islands, and now from Australia, with bathymetric range, 35– 140 m.

Figures

Fig. 6.ɹA: Hyastenus campbelli Griffin and Tranter, Ə (NSMT-Cr 30717; CB 7.7mm excluding lateral tubercles×PCL 12.4mm) from sta. 29. Dorsal view. B–C: Phalangipus australiensis Rathbun, ovig. ♀ (NSMT-Cr 30724; CB 13.2mm×PCL 13.0mm) from sta. 32. Dorsal (B) and lateral (C) views. D–E: Austrolibinia gracilipes (Miers), Ə (NSMT-Cr 30714; CB 11.0mm excluding lateral spines×PCL 9.5 mm) from sta. 30. Dorsal (D) and anterior dorsal (E) views. F–H: Hyastenus kyusyuensis (Yokoya), Ə (NSMT-Cr 30720; CB 5.3mm excluding branchial spines×PCL 8.7mm) from sta. 29. Dorsal (F), ventral (G) and lateral (H) views.