Pagurixus tweediei ( Forest, 1956 )

Osawa, Masayuki, Kawai, Takashi & Sakamaki, Takashi, 2013, New records of Pagurixus Melin, 1939 (Crustacea: Decapoda: Paguridae) from the Ryukyu Islands, southwestern Japan, with description of a new species, Zootaxa 3669 (3), pp. 350-366 : 357

Pagurixus tweediei ( Forest, 1956)

( Fig. 2D )

[New Japanese name: Suneobi-himehonyardokari]

Eupagurus (Pagurixus) tweediei Forest, 1956: 50 , pl. 4 [type locality: Cocos (Keeling) Islands].

Pagurus (Pagurixus) tweediei .— Dechancé 1964: 38.— Ball & Haig 1972: 103.— Lewinsohn 1982: 58.

? Pagurixus tweediei .— Morgan 1992: 171.

? Pagurixus cf. tweediei .— Gherardi & McLaughlin 1994: 644.

Pagurixus tweediei .— Davie 2002: 82 (in part).— Komai & Osawa 2006: 25 , figs 8–11, 44B, 47.— McLaughlin et al. 2010: 32 (list).

Material examined. Kume-jima: “KUMEJIMA 2009” stn Dive 28 (Oyako-iwa), 26°17.5´N, 126°47.9´E, 0–20 m, 17 Nov. 2009, 1 male (sl 2.0 mm), RUMF-ZC 2340 ; “KUMEJIMA 2009” stn Trawl 29, 26°17.6´N, 126°52.9´E, 90.0– 91.3 m, 13 Nov. 2009, 1 female (sl 2.1 mm), RUMF-ZC 2341 . Okinawa-jima: Zatsun, Kunigami, 0.5 m, 29 Aug. 2010, coll. M. Osawa, 1 male (sl 2.5 mm), RUMF-ZC 2342 ; Zatsun, Kunigami, intertidal, 8 May 2012, coll. M. Osawa, 2 ovig. females (sl 2.0, 2.1 mm), RUMF-ZC 2343 ; Uza, Yomitan, small cave, intertidal, 22 Nov. 2012, coll. R . Yoshida, 1 male (sl 3.2 mm), 1 female (sl 2.8 mm), RUMF-ZC 2344 .

Coloration in life. The coloration of the present specimens agrees well with that of P. tweediei described by Komai & Osawa (2006, fig. 44B). See Fig. 2D .

Distribution. Previously known with certainty from Cocos (Keeling) Islands in the eastern Indian Ocean, and Ogasawara Islands, Guam, Society Islands in the western Pacific Ocean; intertidal to 7 m ( Komai & Osawa 2006). Now also recorded from Okinawa-jima and Kume-jima in the central Ryukyu Islands; intertidal to 91.3 m. One female specimen from Kume-jima (RUMF-ZC 2341) was collected from rather unusual depth (90.0– 91.3 m) for P. tweediei , which typically inhabits intertidal and shallow subtidal areas.

Habitat. Rocky and coral reefs, under rocks and dead coral rubble, or in small shoreside cave near coral reefs.

Remarks. Until the present report, P. tweediei has not been recorded from the Ryukyu Islands, although this species is widely distributed from the eastern Indian Ocean to the western Pacific Ocean ( Komai & Osawa 2006; Osawa & Komai 2007). The previous record of P. tweediei from Japan was based exclusively on the material from the remote Ogasawara Islands ( Komai & Osawa 2006).

Komai (2010) discussed that the presence of a ventrolateral distal spine on the merus of the third pereopod is one of morphological characters distinguishing P. tweediei from P. formosus . The type material of P. formosus lacks this spine. However, in the present specimens referred to P. tweediei , this character appears to be variable. The spine is absent or reduced to a low protuberance in one male from Kume-jima (RUMF-ZC 2340) and two females from Okinawa-jima (RUMF-ZC 2343), whereas it is present but very small in the other specimens.

Figures

FIGURE 2. Entire animal, dorsal view. A, Pagurixus carinimanus Komai & Osawa, 2006, female (sl 1.7 mm), stn K 1-1, Kuchino-shima, RUMF-ZC 2328 (left cheliped and left second and third pereopods missing); B, Pagurixus formosus Komai, 2010, male (sl 2.9 mm), Benoki, Kunigami, Okinawa-jima, RUMF-ZC 2335; C, Pagurixus formosus Komai, 2010, male (sl 2.7 mm), “KUMEJIMA 2009” stn Dive 28, Kume-jima, RUMF-ZC 2334; D, Pagurixus tweediei (Forest, 1956), male (sl 2.5 mm), Zatsun, Kunigami, Okinawa-jima Island, RUMF-ZC 2342. (third pereopods missing); E, Pagurixus pseliophorus Komai & Osawa, 2006, male (sl 2.6 mm), Zatsun, Kunigami, Okinawa-jima, RUMF-ZC 2339 (right third pereopod missing); F, Pagurixus pseliophorus Komai & Osawa, 2006, ovig. female (sl 2.7 mm), Benoki, Kunigami, Okinawa-jima, RUMF-ZC 2336.