Pugettia pellucens Rathbun, 1932

Ohtsuchi, Naoya, Kawamura, Tomohiko & Takeda, Masatsune, 2014, Redescription of a poorly known epialtid crab Pugettia pellucens Rathbun, 1932 (Crustacea: Decapoda: Brachyura: Majoidea) and description of a new species from Sagami Bay, Japan, Zootaxa 3765 (6), pp. 557-570 : 558-563

Pugettia pellucens Rathbun, 1932

[Japanese name: Ko-yotsuha-mo-gani] ( Figs. 1–3 , 6 A–E)

Pugettia quadridens pellucens Rathbun, 1932: 31 [type locality: Omai Zaki Light (= Omae-Zaki Light, Suruga Bay)].— Sakai 1938: 258, pl. 36, fig. 3; 1976: 197–198, text-fig. 104.— Ikeda 1981: 15 (list).— Takeda 1981: 36 (list).— Miyake 1983: 206 (list).— Griffin & Tranter 1986: 92 (key).— Marumura & Kosaka 2003: 32 [in part].

Pugettia pellusence [sic.].— Sakai 1986: 2 (list).

Pugettia quadridens .— Ariyama 1995: 3, fig. 3D–F.

Pugettia pellucens .— Muraoka 1998: 24.— Takeda et al. 2006: 196 (list); 2011: 29, fig. 16-68.—Ng et al. 2008: 101 (list).— Wicksten & Stachowicz 2013: 359 (list).

Pugettia quadridens intermedia .— Marumura & Kosaka 2003: 32 (in part).

[Not] Pugettia quadridens pellucens .— Marumura & Kosaka 2003: 32 [in part = P. intermedia Sakai, 1938 , P. quadridens (De Haan, 1839) , P. vulgaris n. sp.]

Material examined. Holotype: USNM 49925, male (CW 9.2 mm, PCL 12.4 mm), Omai Zaki Light [= Omae-Zaki Light], N17°E, 14.5 miles, 34–37 fathoms, mud, gravel, rock, 16 May 1900, Albatross, station 3730 (photographs and drawings courtesy of P. K. L. Ng).

Non-types: CBM-ZC 11021, 1 male (CW 7.5 mm, PCL 11.4 mm), Banda, Tateyama, Boso Peninsula, Chiba, 30–60 m, 22 May 1990, dredge, coll. T. Komai.—CBM-ZC 2569, 1 male (CW 10.3 mm, PCL 13.4 mm), off Hota, Kyonan, Uraga Strait, 16 May 1996, gill-net, coll. T. Komai.—CBM-11022, 1 male (CW 9.8 mm, PCL 13.0 mm), 1 female (CW 10.9 mm, PCL 13.4 mm), Tomiyama Fishery Port, Minami-Boso, raft for aquaculture, 29 December 1995, hand, coll. T. Komai.—Private collection of H. Ikeda, 1 male (CW 12.8 mm, CL 19.0 mm), off Hayama, Kanagawa, 10 m, spring 1970, coll. H. Ikeda.—WPNH-Na-Cr 0314-2, 1 male (CW 13.7 mm, PCL 17.7 mm), Hayama, Kanagawa, 6 May 1973, coll. S. Nagai (examined by Marumura & Kosaka 2003)—WPNH-Na-Cr 0 313, 2 females (CW 5.3, 7.1 mm, PCL 7.6, 9.3 mm), off Shionomisaki, Wakayama, 30 m, coll. S. Nagai (examined by Marumura & Kosaka 2003)—KPM-NH 104094, 1 male (CW 9.2 mm, PCL 12.4 mm), Wakayama, coll. S. Sekiguchi (examined by Sakai 1938).—NSMT-Cr 22176, 1 male (CW 13.5 mm, PCL 15.4 mm), Nayaura Bay, Kumano Sea, Mie Prefecture, 5 m, February 2010, gill-net, coll. local fishermen.— KMNH IvR 100007, 1 male (CW 9.5 mm, PCL 12.6 mm), Okinoshima I., Genkai Sea, Fukuoka, 12–29 May 1933.

Redescription. Carapace ( Figs. 1 A, 2) elongated pyriform; carapace regions not markedly defined; gastric, cardiac, branchial regions moderately elevated; protogastric region with 2 oblique rows of hooked setae on either side of midline; intestinal region weakly elevated; cardiac, branchial, intestinal regions sometimes densely covered with club-shaped setae; no median spines or tubercles on gastric, cardiac, intestinal regions.

Rostral spines ( Figs. 1. 2 ) relatively long, 0.4–0.5 of postrostral carapace length (mean RL/PCL±SD = 0.42±0.04, N = 4), moderately diverging anteriorly, each with 2 dorsal rows of hooked setae in proximal 0.5–0.7. Preorbital spine ( Figs. 1 A, 2, 3A, B, D) strong, acuminate, directed anteriorly; lateral margin of supraorbital eave usually nearly straight, sometimes concave. Orbital hiatus ( Fig. 3 A) deep, distinctly separating supraorbital eave from postorbital lobe. Postorbital lobe ( Figs. 1 A, C, 2, 3A, D) slightly compressed dorsoventrally, moderately large, tapering to acute or subacute apex, directed obliquely anteriorly in dorsal view, nearly horizontal in lateral view. Hepatic lobe ( Figs. 1 A, 2, 3A) moderately large, acuminate, distinctly larger than postorbital lobe, fused basally with postorbital lobe, projecting laterally, distal part sometimes curved anteriorly. Concavity between postorbital and hepatic lobes U- or L-shaped ( Figs. 1 A, 2, 3A). Anterolateral margin ( Figs. 1 , 2 ) with rows of hooked setae; lateral surface inferior to anterolateral margin with 2 small spines ( Fig. 1 C). Epibranchial spines ( Figs. 1 A, 2) acute, positioned at posterior 0.3 of postorbital carapace length, varying in size.

Subhepatic region ( Figs. 1 B, 3B) unarmed. Pterygostomial region ( Figs. 1 B, 3B) not particularly inflated, with 3 or 4 tubercles along pleural suture.

Basal antennal article ( Fig. 3 D) with ventral surface unarmed, bearing low, blunt longitudinal ridge mesial to midline; distolateral angle produced into small subacute spine directed anterolaterally; lateral margin faintly sinuous, with small tubercle basally. Antennal peduncle consisting of 2 articles flattened dorsoventrally; penultimate article ( Figs. 1 B, 3B) with lateral margin sharply carinate over entire length, mesial margin bluntly carinate, ventral surface bluntly carinate along midline; ultimate article distinctly shorter than penultimate article, distal end nearly twice broader than proximal end.

Third maxilliped ( Fig. 3 C, D) unarmed on surface; ischium with shallow median groove; anterolateral angle of merus produced, slightly upturned; exopod unarmed.

Anterolateral angle of buccal frame ( Figs. 1 C, 3C, D) rounded, strongly produced anteriorly, not overlapped by anterolateral angle of merus of third maxilliped when closed.

Chelipeds ( Figs. 1 , 2 A, 3E–I) equal in size, similar in shape. Ischium ( Figs. 2 B, 3I) weakly swollen ventrally in distal half; mesial margin obtusely ridged; distolateral lobe distinct, compressed. Merus ( Figs. 1 , 2 , 3 F, G) prismatic, proximal half thickened; dorsal surface ( Figs. 1 A, 3G) with distinct longitudinal keel in proximal 0.8, with 3 lamellar teeth or lobes; outer surface ( Figs. 1 A, 3F) with obtuse longitudinal ridge bearing 3 or 4 rudimentary tubercles; ventral surface ( Figs. 1 B, 3F) with bluntly ridge bearing 3 low tubercles; upper inner surface ( Figs. 1 A, B, 2A, 3G) generally unarmed, bluntly ridged; inner margin armed with low convexity proximally; distal margin with 2 prominent knobs at articulation with carpus (outer knob larger than inner); prominent, obliquely erect, rounded or subrectangular lobe on upper side ( Figs. 1 A, 3F, G). Carpus ( Figs. 1 , 2 A, 3H) moderately inflated, with distinct, bi- or tri-tuberculate ridge on upper surface; inner margin sharply crested, divided into 1–4 faint lobes, proximalmost lobe sometimes prominent; outer margin distinctly crested. Chelae ( Figs. 1 , 2 , 3 E) almost twice longer than high (chela length/height = 1.9–2.2, N = 4) in adult males; upper margin of palm weakly to sharply crested, with small rounded lobe basally, lower margin obtusely ridged.

Ambulatory legs ( Figs. 1 , 2 A) decreasing in length posteriorly. Meri each with small upper distal tubercle, otherwise unarmed. Carpi each with shallow depression on upper surface. Dactyli each with 2 rows of small calcareous spines on flexor surface.

Male first gonopod ( Fig. 6 A–E) trilobate in distal one-fourth. Dorsal lobe varying from triangular to elongate, strap-like, when elongate, strongly bent inwards, sometimes crossing tip of mesial lobe ( Fig. 6 C). Mesial lobe located mesial, close to base of dorsal lobe, triangular, slightly smaller than ventral lobe ( Fig. 6 A, C). Ventral lobe triangular with acute or subacute tip. Hiatus between dorsal and mesial lobe varying from narrow to wide.

Size. Largest male PCL 17.7 mm, CW 13.7 mm, largest female PCL 13.4 mm, CW 10.9 mm.

Distribution. So far known only from Japan, including Sagami Bay, Kii Peninsula, Osaka Bay, off Tottori, and Genkai Sea; 5–50 m deep. Inhabiting bottoms of sand or weedy rocks.

Remarks. As mentioned above, Pugettia pellucens have been rarely recorded in previous literature since the original description by Rathbun (1932) (see synonymy). Sakai (1938) examined five specimens from Hatsushima Islet (Sagami Bay), Shimoda (Izu Peninsula), and Wakayama (Kii Peninsula), and Sakai (1976) added six specimens from Manazuru (Sagami Bay) and Kii Peninsula. Recently, Ikeda (1981), Marumura & Kosaka (2003) and Takeda et al. (2011) also listed this species from off Hayama and Nagai (Sagami Bay), off Shionomisaki (Kii Peninsula), and off Tottori (Sea of Japan), respectively. We have tried to locate these specimens in KPMNH, NSMT, TPM, WPM, and the private collection of Hitoshi Ikeda. We managed to find one male specimen from Wakayama that was studied by Sakai (1938) (KPM-NH 104094; Fig. 2 ). This specimen agrees well with the holotype male (USNM 49925; Fig. 1 ), and is identified with P. pellucens without hesitation. We also confirmed that the recent record from Sagami Bay by Ikeda (1981) is indeed P. pellucens . We also located eight dried specimens from off Shionomisaki in the collection of WPM, referred to P. p e l l u c e n s by Marumura & Kosaka (2003). Our reexamination showed that only two female specimens represented P. pellucens , with the rest belonging to P. intermedia , P. quadridens and P. vulgaris n. sp.

Although previously regarded as a subspecies of P. quadridens , Pugettia pellucens is readily distinguished from P. quadridens by the proportionately more elongated pyriform carapace (versus sub-rhomboidal in P. quadridens ), relatively long rostral spines (RL/PCL 0.4–0.5 in P. pellucens versus 0.1–0.3 in P. quadridens ), fairly compressed postorbital lobe separated from the orbital eave by a wide hiatus (versus moderately thick, separated by a narrow hiatus in P. quadridens ), epibranchial spines strongly projecting from the carapace lateral margins, and located at the posterior 0.3 of PCL (versus not projecting from the carapace lateral margin, and located at the posterior 0.4 of PCL in

P. quadridens ), the male first gonopod is trilobate in distal one-fourth (versus in one-fifth in P. quadridens ), and the mesial lobe of the male first gonopod is projected anteriorly (versus extending horizontally in P. quadridens ; cf. Sakai 1936: 88, fig. 37; Griffin & Tranter 1986: 94, fig. 28e, f).

Ariyama (1995: fig. 3D–F) figured the male first gonopod of a male specimen that he referred to P. quadridens , but his figure rather well agree with that of P. pellucens . Consequently, Ariyama’s (1995) record of P. quadridens is here also referred to P. pellucens .

Figures

FIGURE 1. Pugettia pellucens Rathbun, 1932. Holotype male from Omae-Zaki, Suruga Bay (USNM 49925: 9.2 mm CW, 12.4 mm PCL). A, dorsal view; B, ventral view; C, right lateral view. Photographs courtesy of P. K. L. Ng.

FIGURE 2. Pugettia pellucens Rathbun, 1932. A, B, male from the coast of Wakayama, Kii Peninsula (KPM-NH 104094: CW 8.6 mm, PCL 12.7 mm). A, overall dorsal view; B, dorsal view of carapace.

FIGURE 3. Pugettia pellucens Rathbun, 1932. Male from coast of Wakayama, Kii Peninsula (KPM-NH 104094: CW 8.6 mm, PCL 12.7 mm). A, B, D, anterior part of carapace, dorsal view (A), ventral view (B), and right lateral view (D); C, left third maxilliped, ventral view; E, left chela, outer view; F, G, merus of right cheliped, ventral view (F) and inner view (G); H, carpus of the right cheliped, dorsal view; I, ischium of the right cheliped, mesial view. Abbreviations: ik, inner knob; im, inner margin; lm, lower margin; om, outer margin; ok, outer knob; um, upper margin.

FIGURE 6. Right male first gonopod of Pugettia pellucens Rathbun, 1932 (A – D, KPMNH 104094: CW 8.6 mm, CW 12.7 mm, the coast of Wakayama, Kii Peninsula; E, NSMT-Cr 22176: CW 13.5 mm, PCL 15.4 mm, Nayaura Bay, Kumano Sea) and Pugettia vulgaris n. sp. (F – I, NSMT-Cr 22172: holotype male, CW 5.8 mm, PCL 7.8 mm, Nagai, Miura Peninsula, Sagami Bay; J, a specimen deposited in AORI, CW 6.7 mm, PCL 9.2 mm, the same locality as holotype). A, F. mesial view of the tips; B, G. lateral view of the same; C, H. upright view of the same; D, I. mesial view of whole G 1. Abbreviations: dl, dorsal lobe; ml, mesial lobe; vl, ventral lobe.