Arcania undecimspinosa De Haan, 1841

Naruse, Tohru, 2014, Description of two new species of Arcania Leach, 1817, from the western Pacific Ocean and redescriptions of A. undecimspinosa De Haan, 1841, and A. elongata Yokoya, 1933 (Crustacea: Brachyura: Leucosiidae), Zootaxa 3814 (3), pp. 301-332 : 302-308

Arcania undecimspinosa De Haan, 1841

( Figs. 1–6 )

Arcania undecimspinosa De Haan, 1841: 135 , pl. 33, fig. 8.— Bell 1855a: 367; 1855b: 309; 1855c: 21.— Herklots 1861: 28.— Ives 1891: 216.— Shen 1931: 107, pl. 10, fig. 1.— Sakai 1937: 123, fig. 15a, pl. 14, fig. 2; 1965: 40 (part?), pl. 16, fig. 2; 1976: 91, pl. 28, fig. 1.— Kamita 1941b, 40, fig. 13.— Holthuis & Sakai 1970: 119, pl. 11, fig. 2.— Miyake 1983: 60, pl. 20, fig. 6.— Dai et al. 1986: 66, fig. 33-1, pl. 8, fig. 1.— Huang 1989: 305, fig. 267.— Dai & Yang 1991: 73, fig. 33-1, pl. 8, fig. 1.—Yamaguchi 1993: pl. 21c.— Yamaguchi & Baba 1993: 318, fig. 101; 2003: 33.— Galil 2001: 197 (part), figs. 3D, 7D (part).— Takeda et al. 2011: 37, fig. 9–26).

Arcania novemspinosa— Hill 1982: 201, pl. 4D.— Dai et al. 1986: 66, fig. 33-2, 3; Dai & Yang 1991: 74, fig. 33-2, 3.

Material examined. Lectotype: RMNH. CRUS.D.790, 1 male, 16.5 × 16.5 mm, Nagasaki, Kyushu, Japan, coll. H. Bürger, 1825–1834.

Paralectotypes: RMNH. CRUS.D.56126, 1 female, 19.2 × 19.2 mm, 3 individuals (sex unknown), 20.3 × 19.9, 21.1 × 21.1 mm, data same as lectotype.

Additional material. Japan: USNM 26280, 1 male, 21.1 × 21.1 mm, 1 female, 21.2 × 21.2 mm, 1 ovig. female, 19.9 × 20.3 mm, Nagasaki, Hizen, Kyushu, coll. Jordan & Snyder, 1900.— USNM 45833, 1 ovig. female, 19.7 × 20.2 mm, Nagasaki, Kyushu, exchange with Imperial Tokyo University.—NSMT-Cr 8371, 1 female, 16.7 × 16.2 mm, Ariake Sea, Kyushu, coll. Sep. 1958.—NSMT-Cr 8200, 1 male, 19.9 × 19.1 mm, Ariake, Kyushu, coll. N. Yoshikawa, 15 June 1982.—NSMT-Cr 8009, 1 male, 16.5 × 15.6 mm, off Jogajima, coll. E. Tsuchida, 11 Mar. 1982.— USNM 1199103, 1 male, Shizuoka, Suruga Bay, Seno Umi, Albatross, stn. D. 3702, 7 May 1900.— USNM 63676, 1 ovig. female, 26.3 × 25.9 mm, Misaki, Japan, coll. A.S. Pearse (bought from Kuma-san), 1930.—NSMT- Cr 3839, 1 female, 24.5 × 23.3 mm, Mikawa-Isshiki, Mikawa Bay, coll. 15 Jan. 1966.— USNM 134198, 19.6 × 18.5 mm, 8.8 mi off Nomasaki, Honshu Island, stn. Alb. D-3725, 13 faths. (ca. 23.8 m), 15 May 1900.—RUMF- ZC-2574, 1 female, 12.6 × 9.9 mm, Takehara City, Hiroshima, 15m, coll. D. Uyeno, 14 Oct. 2007.—NSMT-Cr 4397, 2 males, ca 25.9 × 25.1 mm, 1 female, 28.2 × 27.2 mm, Mimase, Kochi, coll. Y. Koyama, 11 May 1973.— USNM 18873, 1 female, 13.2 × 13.1 mm, Japan, coll. Mr. Sakamoto (passed through Garrett Droppers).

Korea: MADBK 171803-017, 1 male, 30.3 × 28.7 mm, 1 female, 22.0 × 21.9 mm, Jinhae-gu, Changwon-si, Gyeongsangnam-do, 1 Aug. 1968.— MADBK 171803-016, 1 male, 30.1 × 30.8 mm, 2 ovig. female, 29.8 × 30.2, 30.8 × 30.2 mm, Namcheon-dong, Suyeong-gu, Busan, 10 July 1968.

China: ZRC 2002.0495, 4 males, 27.2 × 26.7—31.0 × 29.8 mm, 1 ovig. female, 31.6 × 31.8 mm, Tuandao, off Qindao, coll. P.K.L. Ng via fishermen, 23–28 Aug. 2002.— USNM 57771, 2 males, 23.9 × 24.8, 31.7 × 31.1 mm, 1 female, 32.1 × 35.1 mm, 1 juv. female (damaged), Tsimei (=Jimei, Fujian), coll. S.F. Light, June 1923.

Taiwan: ZRC 1997.0382, 1 male, 18.3 × 16.7 mm, Donggang, Pingtung, coll. P.K.L. Ng, 5 Aug. 1996.

Redescription. Carapace rounded, dorsal surface covered somewhat sparsely by columnar granules, granules larger at gastric to intestinal regions ( Figs. 1 a, 2, 3a); pterygostomial, subepatic regions evenly covered with rounded granules ( Fig. 2 b). Front divided into 2 triangular lobes by obtuse triangular gap, lobes not strongly produced, weakly rounded in some large individuals ( Figs. 1 a, 2a). Carapace with subhepatic, anterolateral, lateral, posterolateral, posterior, intestinal spines. Anterolateral spines smallest, followed in size by subhepatic spine, other spines of almost same length. Only branchiocardiac groove distinct. Antennular fossae oblique, antenna excluded from antenular fossa by plate extended from posterior margin of antennullar basal segment, plate with triangular lobe anteriorly, seta posteriorly. Mesial end of infraorbital margin forming dorsoventrally compressed, sharp, triangular spine. Anteromesial corner of pterygostomial region, anterolateral margin of buccal cavern forming laterally compressed triangular spines fitting distal part of exopod of closed mxp3; distance between spines relatively narrow due to slender exopod of mxp3.

Eyes fitting within orbit, only corneal part slightly exposed.

Mxp3 ( Figs. 2 b, 3b) sparsely covered with rounded granules; merus length about two-fifths of ischium; ischium, merus each with longitudinal groove on mesial third, half; female merus with longitudinal row of setae along longitudinal groove. Exopod narrowed at level of proximal two-fifths of merus, gap between narrowed part of exopod, merus thus fitting triangular spine of anterolateral margin of buccal cavern.

Thoracic sternites 4–7 ( Fig. 1 b) covered with rounded granules; granulation sparser than pterygostomial region. Sternal button of abdominal holding on anterior end of thoracic sternite 5 at lateral slope of thoracic cavity, button fitting proximolateral cup of somite 6. Penis coxal. Vulva on mesial end of thoracic suture 5/6, on somite 6 but extending mesial end of suture 5/6 anteriorly ( Fig. 6 ); posterolateral part of vulva swollen; opening narrowed laterally, entire mesially.

Chelipeds ( Fig. 2 a) moderately long, subequal. Merus slender, shorter than chela, entirely covered with rounded granules, granules smaller on lower surface. Carpus, palm sparsely covered with minute granules, carpus smooth without knob on external margin. Fingers slender, gape absent when closed, with 14–18 almost equidistantly placed, small teeth with much smaller teeth throughout. Ambulatory legs slender; merus longest of articles, covered with minute rounded granules. Carpus, propodus covered with minute granules. Dactylus mesiolateraly depressed in cross-section, with sharp keels on mid-lines of mesial, lateral surfaces, keel on lateral surface flanked by rows of setae.

Abdomen ( Fig. 1 b) with sparse, rounded granules; somites 3–5 fused, with proximolateral protuberances on external surface, each protuberance not distinctly larger than central part between two protuberances. Lateral margins of somite 6 convex in large individuals. G1 ( Figs. 4 a–c, 5) slender, nearly straight, slightly curved dorsally in mesial view; distal part only slightly upcurved in mesial view, lateral margin wrapping onto mesial margin submedially, forming pipe-like opening. G2 ( Fig. 4 d) short, opening facing dorsally in situ.

Coloration. Body and cheliped merus pinkish dorsally, with a pair of reddish lines and semicircular marks on the dorsal surface ( Takeda et al. 2011: fig. 9–26).

Geographical distribution. Japan (Pacific coast: from Sagami Bay to Kochi; Kyushu: Ariake, Nagasaki [type locality]); Korea (Namcheon-dong, Jinhae-gu); China (Qingdao; Tsimei; Fukien; Hangzhou; Kwangtung; Cheung Chau Island, Hong Kong); Taiwan (Donggang). (De Haan 1844; Shen 1931; Sakai 1937; Miyake 1983; Huang 1989; present study).

Remarks. Arcania undecimspinosa De Haan, 1841 , was described from material collected at Nagasaki, western Kyushu, Japan. Yamaguchi & Baba (1993) and Fransen et al. (1997) listed 15 syntypes, of which five specimens are preserved in ethanol and the rest are dried. The ethanol-preserved specimens comprise three males (two of which are confirmed by the presence of fragmented male thoracic sternites), one female, and one individual (sex unknown). Yamaguchi & Baba (1993) indicated that the ethanol-preserved lot contained a lectotype and paralectotypes, but they did not note nor indicate which individual was selected as lectotype. Since Yamaguchi & Baba’s (1993) lectotype designation is invalid, the lectotype is here designated for a male (RMNH.CRUS.D.790; 16.5 × 16.5 mm) form the ethanol-preserved specimens ( Figs. 1 , 4 ). The lectotype is in a relatively good condition, allowing the observation of the G1 ( Fig. 4 a–c). Arcania undecimspinosa is characterized by a rounded carapace ( Figs. 1 a, 2, 3a), front with triangular lobes with an almost regular triangular gap between the lobes ( Figs. 1 a, 2a, 3a), distinct marginal spines in the carapace ( Figs. 1 a, 2a, 3a), dorsal surface of the carapace being rather sparsely covered by columnar granules (granules larger from gastric to intestinal regions) ( Fig. 2 b), almost straight G1 with pipe-like distal end ( Figs. 4 a–c, 5) and a vulva consisting of a narrowed lateral end and with an entire mesial margin ( Fig. 6 ).

Arcania undecimspinosa is morphologically most similar to A. cornigera n. sp. (see Remarks under A. cornigera n. sp.). It should be noted that A. undecimspinosa and A. cornigera n. sp. have been collected from the same areas (e.g. Kochi, Pacific coast of Shikoku, Japan; Donggang, southwestern Taiwan). This superficial similarity and overlapping distribution may have led to misidentifications. Among the A. undecimspinosa specimens recorded by Yokoya (1933), the specimens from Kyo-gasaki (KMNH IvR 400,102; st. 540), Goto Islands (KMNH IvR 400,104; st. 451) and Jeju Island (KMNH IvR 400,103; labelled as Saishu-to, st. 454) are indeed A. cornigera n. sp. Sakai (1965) also figured the anterior part of the cephalothorax of A. cornigera n. sp. ( Sakai 1965: fig. 6a) and the habitus of A. undecimspinosa s.s. as A. undecimspinosa ( Sakai 1965: pl. 16, fig. 2).

Miers (1877) described A. granulosa from Moreton Bay, Australia, which was cited by Haswell (1880; 1882). Miers (1879) subsequently synonymized A. granulosa under A. undecimspinosa . Subsequent authors (e.g. Miers, 1884; Henderson, 1893; Campbell 1971; Davie & Short 1989) recorded “ A. undecimspinosa ” from Moreton Bay as well. Miers’s (1877) specimen is, however, only about 1/ 3 inch carapace length by 1/ 4 inch carapace width (about 8.5 × 6.4 mm), which is too small to allow the correct identification of A. undecimspinosa and allied species. Galil (2001) identified Campbell & Stephenson’s (1970) A. novemspinosa from Moreton Bay as A. undecimspinosa . Campbell & Stephenson’s drawing (1970: fig. 13), however, shows a distally curved G1 with an oblique line of setae, proportionally too broad posterior teeth and almost indiscernible anterolateral teeth of the carapace. This is clearly neither A. undecimspinosa ( Figs. 1 a, 2a, 3a, 4a–c, 5) nor A. novemspinosa ( Galil 2001, figs. 2F, 6C; Fujii & Naruse 2013: figs. 1, 2A). The condition of the G1 and the posterior teeth of the carapace of Campbell & Stephenson’s (1970) “ A. novemspinosa ” are rather closer to A. foliolata Galil, 2001 . The taxonomic status of A. granulosa as well as the Arcania species collected from Moreton Bay, including “ A. elongata ” of Campbell (1971) (see Remarks for A. elongata ), should be reconsidered in future studies.

Alcock (1896: 267) and Tan (1996: 1028) mentioned that A. novemspinosa may be synonymous with A. undecimspinosa , but they are clearly different species (see Galil 2001; Fujii & Naruse 2013; present study).

Hill (1982: 201, pl. 4D) recorded “ A. novemspinosa ” from Hong Kong, but its less produced and obtuse frontal lobes indicate that it is A. undecimspinosa . He also noted the body color of the specimen as “uniformly pinkishbrown with two faint broad darker stripes dorsally down the carapace” ( Hill 1982: 201), which agrees with the coloration of A. undecimspinosa .

Galil (2001) listed a record of Arcania erinacea from Pakistan by Tirmizi & Kazmi (1988: 72) in the synonymy list of A. undecimspinosa . The drawing by Tirmizi & Kazmi (1988: fig. 20), however, clearly shows serrate meri of the cheliped and fourth ambulatory leg, which are not observed in A. undecimspinosa . Tirmizi & Kazmi (1988: 76, fig. 22) provisionally identified other specimens from Karachi, Pakistan as A. undecimspinosa . As Tirmizi & Kazmi (1988) noted, the G1 of the Pakistani specimen differs markedly from that of A. undecimspinosa s.s. in its strong distal curvature over the distal third ( Tirmizi & Kazmi 1988: fig. 22G). The distally bent G1 of the Pakistani specimen may be similar to that of A. brevifrons Chen, 1989 , but the former differs from the latter by “half tube bent portion” of the distal part of the G1 ( Tirmizi & Kazmi 1988: 79) (flattened in Chen 1989: fig. 32e; Galil 2001: fig. 4A). The identities of the two Pakistani species remain questionable.

Figures

FIGURE 1. Arcania undecimspinosa De Haan, 1841. Lectotype. RMNH. CRUS. D. 790, male, 16.5 × 16.5 mm, Nagasaki, Kyushu, Japan; a, cephalothorax, dorsal view; b, cephalothorax, ventral view.

FIGURE 2. Arcania undecimspinosa De Haan, 1841. NSMT-Cr 4397, male, ca. 25.9 × 25.1 mm (front damaged), Kochi, Japan; a, habitus; b, cephalothorax, frontal view.

FIGURE 3. Arcania undecimspinosa De Haan, 1841. ZRC 2002.0495, male, 31.0 × 29.8 mm, Qindao, China; a, cephalothorax, dorsal view; b, cephalothorax, ventral view.

FIGURE 4. G 1 and G 2 of Arcania undecimspinosa De Haan, 1841. Lectotype. RMNH. CRUS. D. 790, male, 16.5 × 16.5 mm; a, left G 1, mesial view; b, left G 1, ventral view; c, distal part of left G 1, ventral view; d, left G 2. Scales = 1 mm.

FIGURE 5. G 1 of Arcania undecimspinosa De Haan, 1841. ZRC 2002.0495, male, 31.0 × 29.8 mm, Qindao, China; a, left G 1, mesial view; b, left G 1, ventral view; c, distal part of left G 1, ventromesial view. Scales = 1 mm.

FIGURE 6. Right vulva of Arcania undecimspinosa De Haan, 1841; a, NSMT-Cr 3839, 24.5 × 23.3 mm, Mikawa Bay, Japan; b, NSMT-Cr 4397, 28.2 × 27.0 mm, Kochi, Japan. Scale = 1 mm.