Pseudohelice subquadrata ( Dana, 1851 )

Hsu, Jhih-Wei & Shih, Hsi-Te, 2024, First records of Parahelice K. Sakai, Türkay & Yang, 2006 and Pseudohelice K. Sakai, Türkay & Yang, 2006 from Vanuatu, with description of a new species of Parahelice (Crustacea: Brachyura: Varunidae), Zootaxa 5476 (1), pp. 138-151 : 147-148

Pseudohelice subquadrata ( Dana, 1851)

( Fig. 4 )

Chasmagnathus subquadratus Dana, 1851: 251 (type locality: possibly New South Wales, Australia).

Helice leachii .— K. Sakai 1939: 698, text-fig. 126.— Dai et al. 1986: 505, fig. 286(5–6), pl. 72(1).

Helice leachi .— K. Sakai 1976: 672, textfig. 370a, b, pl. 228(2).

Helice (Helice) leachii .— Dai & Yang 1991: 553, fig. 286(5–6), pl. 72(1).

Pseudohelice (Pseudohelice) subquadrata .— K. Sakai et al. 2006: 37, figs. 53–59 (part).

Pseudohelice subquadrata .— Ng et al. 2017: 110 (list).— Hsu et al. 2022: 96 , figs. 1, 2.— Prema et al. 2022: 13 (p. 3). Pseudohelice quadrata [sic].— Ng et al. 2008: 227 (list).

For synonyms before 2023, see K. Sakai et al. (2006) and Hsu et al. (2022).

Material examined. 1 male (20.2 × 18.1 mm), ZRC 2023.0248 , st. VM34, Palikulo Peninsula , Sanma Province, Espiritu Santo Island, Vanuatu, 23 Sep. 2006 ; 2 males (16.1 × 14.3, 13.9 × 12.0 mm), 1 female (14.4 × 12.3 mm), 1 ovig. female (16.7 × 14.3 mm), ZRC 2023.0249 , st. VM34, Palikulo Peninsula , Sanma Province, Espiritu Santo Island, Vanuatu, 23 Sep. 2006 .

Diagnosis. Carapace ( Fig. 4A ) quadrate, slightly broader than long, ca. 1.2 times as broad as long; surface convex, irregularly punctate and granulate, with noticeable epigastric groove. Frontal margin slightly concave. Anterolateral margins with 3 teeth including orbital tooth. Suborbital crista sexually heteromorphic; in male ( Fig. 4D ), mesial part with several small rounded or elongated tubercles, followed by well-spaced several large, heteromorphic, elongated and less convex tubercles, lateral part with 1 significantly largest, elliptical and very convex tubercle, and 2–5 large convex tubercles; in female, mesial part with several dense small rounded tubercles, followed by closely spaced several larger, elongated, less convex and mostly unfused tubercles, lateral part with 1 largest and 2–5 larger convex tubercles; tubercles in lateral part more convex in male, less convex in female. Chelipedal palm stout, almost glabrous; usually unequal in male, equal in adult female. Ambulatory legs ( Fig. 4A ) slender, anterior margins of merus, carpus, and propodus covered with dense short setae. G1 ( Fig. 4E–F ) stout, distal part relatively flat with small chitinous beak-like structure distally, blunter; female vulvae with elongated semicircular sternal cover; sunken on inner part.

Distribution. Western Pacific, from French Polynesia, Samoa, Fiji, Vanuatu, New Caledonia, eastern Australia, Caroline Is., Guam, Japan (including Ryukyus and Ogasawara Is.), Korea (Jejudo), Taiwan, China (Hainan), Philippines, Indonesia (Sulawesi, Bali, and Lombok), to western Thailand (Surin I., Phang Nga) (K. Sakai et al., 2006; Hsu et al. 2022; this study).

Remarks. For the morphological comparison among the three species in Pseudohelice , see Hsu et al. (2022) and Prema et al. (2022). This is a newly recorded species to Vanuatu, within its distributional range in the western Pacific (see above distribution).

Figures

FIGURE 4. Pseudohelice subquadrata (Dana, 1851). A–F, male (20.2 × 18.1 mm, ZRC 2023.0248). A–F, male (11.2 × 9.0 mm). A, dorsal view; B, ventral view; C, outer view of left male cheliped; D, left male suborbital crista; E, F, dorsal view of male right G1.