Xiphonectes longispinosus ( Dana, 1852 ) sensu Sakai (1939)

Shaga, I Bevin, Priya, K, Ramar, Selvakumar, Srinidhi, S, Mohan, G Chandra, Ranganathan, Sukanya, Moulvi, S M M & Mani, Bhuvaneswari, 2023, A Small Collection of Subtidal Crabs (Crustacea: Decapoda: Brachyura) from the Palau Islands Collected by Dredging, Bulletin of the National Museum of Nature and Science. Series A, Zoology 49 (1), pp. 7-42 : 22-24

Xiphonectes longispinosus ( Dana, 1852) sensu Sakai (1939)

( Fig. 7G )

Material examined. Kayangel Atoll , north of Babelthuap I., Palau Is., lagoon, dredged, 4 m in depth; 1♂ (cb 17.6 mm including epibranchial tubercles×cl 7.1 mm), NSMT-Cr 30978; 3 ♂♂ (10.2× 4.9 mm ─ 19.5× 8.5 mm), 1 juv., NSMTCr 30979; July 6, 1980; K. Baba leg.

Remarks. The taxonomical and nomenclatural problems of the Portunus / Xiphonectes longispinosus complex were resolved by Spiridonov (2016) who checked many synonymous species, examined the syntypes of Amphitrite longi-spinosa Dana, 1852 , and established X. tuerkayi sp. nov. distinct from X. longispinosus s. str. As a male (NSMT-Cr 30978) among four males and one juvenile in the present specimens was shown in Fig. 7G , the epibranchial spine is remarkably long, nearly half of the cb; the lateral end of the carapace posterior margin is strongly angulated; the frontal margin is four-lobed, with two small median lobes; and the merus and palm of the cheliped are slender and elongated. These characters agree with the figure given by Crosnier and Thomassin (1974) and also with a photograph given by Sakai (1939), and seem to be somewhat different from the photographs given by Rathbun (1906) and Edmondson (1954) in the armature of the carapace anterolateral teeth and the length of the epibranchial tooth, and the length and stoutness of the chelipeds. Nagai (1981) recorded a male from Wakayama Prefecture in the Pacific coast of central Japan; that illustration is similar to the photograph given by Sakai (1939) except for the slightly stouter chelipeds. The present specimen having the extremely slender chelipeds is referred just to X. longispinosus sensu Sakai (1939) .

Distribution. The X. longispinosus complex is known from the wide area of the Indo-West Pacific, but the species referred to X. longispinosus sensu Sakai (1939) is reliably known only from Japan and Madagascar. New to the Palau Islands.

Figures

Fig. 7. A–B: Thalamita quadrilobata Miers, ♀ (NSMT-Cr 30974; cb 10.8×cl 7.4mm). C–D: Thalamonyx gracilipes A. Milne-Edwards, ♂(NSMT-Cr 30976; cb 7.6×cl 5.9mm). E–F: Thalamita chaptalii (Audouin), ♂ (NSMT-Cr 30970; cb 12.6×cl 8.2mm) (E); ♂ (NSMT-Cr 30971; cb 8.6×cl 6.0mm) (F). G: Xiphonectes longispinosus (Dana) sensu Sakai (1939), ♂ (NSMT-Cr 30978; cb 17.6mm including epibranchial tubercles×cl 7.1 mm). H: Thalamita sexlobata Miers, ovig.♀ (NSMT-Cr 30975; cb 9.0×cl 6.3mm).