Pagurus hedleyi ( Grant & McCulloch, 1906 )

Rahayu, Dwi Listyo, 2022, Hermit crabs of Singapore (Crustacea: Decapoda: Anomura: Diogenidae, Paguridae), with description of two new species, Raffles Bulletin of Zoology 70, pp. 329-363 : 352

Pagurus hedleyi ( Grant & McCulloch, 1906)

( Fig. 14A )

Eupagurus kirkii Miers, 1884: 267 , pl. 28, fig. C (name preoccupied by Eupagurus kirkii Filhol, 1883 ; type locality: Arafura Sea).

Eupagurus hedleyi Grant & McCulloch, 1906: 37 (type locality: Arafura Sea; replacement name for Eupagurus kirkii Miers, 1884 ).

Pagurus hedleyi ; Haig & Ball, 1988: 185, fig. 13.

Pagurus kulkarnii: Morgan, 1987b: 182 ; Morgan, 1990: 27 (not Pagurus kulkarnii Sankoli, 1962 ).

Material examined. 1 male, 3.8 mm ( ZRC 2021.0241 ), SEA3607, Outside Punggol jetty, 1°25.360′N 103°54.201′E, 11.3 m, sandy mud, 16 January 2014 ; 1 female, 4.0 mm ( ZRC 2021.0242 ), SEA7151, 1°21.908′N 103°38.628′E, 11 m, gravel, mud, 9 April 2014 ; 1 male, 3.6 mm ( ZRC 2021.0243 ), SEA5992, Between Tekong East and Pengarang, 01°23.914′N 104°05.353′E, 10.6–10.7 m, sandy, broken shell, 25 March 2014 ; 1 male, 2.7 mm, 1 ovigerous female, 2.9 mm ( ZRC 2021.0244 ), SEA4280, 1°19.911′N 103°37.657′E, 7.5–7.7 m, sandy mud, fine shell, 11 February 2014 ; 3 males, 3.1–3.5 mm, 3 ovigerous females, 2.7–3.8 mm ( ZRC 2021.0245 ), st. Beting Bornok , coll. H. Wong, 28 October 2015 ; 1 male, 3.1 mm, 1 female, 3.6 mm ( ZRC 2021.0246 ), st. SD150, Kusu Island , 10.7 m, 1 June 2013 ; 1 male, 3.8 mm, st. IT80, Terumbu Bemban , rocky reef, 26 May 2013 ; 2 males, 4.2–4.4 mm ( ZRC 2021.0247 ), st. IT86, Cyrene Reef , 1°15.374′N 103°44.816′E, 23 May 2013 ; 2 males, 1.6–2.7 mm ( ZRC 2021.0248 ), Lazarus Island , 20 May 2011 ; 1 male, 1.6 mm ( ZRC 2021.0249 ), st. DR91, 01°12.561′N 103°51.322′E, 46–72 m, 27 May 2013 ; 1 male, 3.3 mm ( ZRC 2021.0250 ), st. SD84, southwest Tekukor , 01°13.800′N 103°50.250′E, 8 m, 27 May 2013 .

Colour in life. Shield mottled with cream and light brown. Ocular peduncles white proximally, narrower white band distally just proximal to corneas, broad blue band medially flanked by similar broad, orange band subproximally and subdistally; corneas grey. Antennular peduncle penultimate segment transparent blue proximally, orange distally; ultimate segment blue; flagella bright orange. Antennal peduncle and antennal acicle generally white with dark brown or black stripes. Chelipeds palm and dactyl cream with short, black or light brown stripes or blotches, spines white; carpus and merus bluish white with large black stripes and blotches. P2 and P3 generally pinkish white; dactyls with short black or dark brown stripes proximally, light brown blotch distally, propodi, carpi, and meri each with short black or dark brown stripes and faint shade of bluish band medially ( Fig. 14A ).

Distribution. Arafura Sea, Torres Strait, coast of Queensland, Singapore; 5–72 m, on sandy mud, gravel and fine shell fragment substrates.

Remarks. Haig & Ball (1988) illustrated the holotype and a specimen from Arafura Sea, and the specimens in this study agree well with their morphological discussion. Among the species of Pagurus having a wing-like projection or lobe on the mesial face of the carpus and merus of the right cheliped, P. hedleyi is most similar to P. kulkarnii in having broad longitudinal stripes on the pereopods. When alive, these two species are easily distinguished from each other by their colouration as follows: in P. kulkarnii the shield has a large dark brown blotch on the dorsal surface, and the ocular peduncle is white with a large brown blotch proximally and narrow brown band just proximal to the cornea ( Fig. 14B ); in P. hedleyi , the dorsal surface of the shield is mottled with white and light brown, the ocular peduncle is white proximally and distally, with a broad blue ring medially flanked by similary broad, orange bands subproximally and subdistally ( Fig. 14A ). Both species have dark brown or black broad stripes on the P2 and P3 that do not reach the distal and proximal ends of each segment, but these stripes are shorter in P. hedleyi and broader in P. kulkarnii . With regard to mophological characters, as stated by McLaughlin (2002a), the presence of one or two irregular rows of strong spines on the dorsal surface and dorsomesial margin of the dactyl of the right cheliped in P. hedleyi , in contrast to scattered low tubercles in P. kulkarnii , separates these two species.

Figures

Fig. 14. A, Pagurus hedleyi (Grant & McCulloch, 1906), male, not measured and sexed, st. SD25, St John’s Island, 01°12.882′N 103°50.952′E, 22 May 2013; B, Pagurus kulkarnii Sankoli, 1962, ovigerous female, 4.2 mm (ZRC 2021.0253); C, D, Pagurus pitagsaleei McLaughlin, 2002a, C, male, not collected, st. SD25, St John’s Island, 01°12.882′N 103°50.952′E, 22 May 2013; D, male, 4.9 mm (ZRC 2021.0239); E, Pagurus tenuilineatus, new species, paratype, male, 4.2 mm (ZRC 2021.0255); F, Spiropagurus spiriger (De Haan, 1849), ovigerous female, not collected, Johor Strait.