A taxonomic revision of the genus Apostichopus (Holothuroidea: Stichopodidae) from Japan Author Woo, Sau Pinn Author Ogawa, Akito Author Tan, Shau Hwai Author Yasin, Zulfigar Author Kajihara, Hiroshi Author Fujita, Toshihiko text Zootaxa 2017 2017-11-16 4350 1 121 135 journal article 31468 10.11646/zootaxa.4350.1.7 6a763966-1f89-40a7-8b6c-f7acd747e4b0 1175-5326 1050945 1894067C-E4E2-4A64-ACDE-1053E034270F Apostichopus armatus ( Selenka, 1867 ) Figs 1–5 Holothuria armata Selenka, 1867 : 330 , pl. XVIII, fig. 66; Lampert, 1885 : 91 . Stichopus armatus ( Holothuria ) : Théel, 1886 : 196 Stichopus ( Holothuria ) armatus : Mitsukuri, 1896 : 408 ; Mitsukuri, 1912 : 164 Stichopus japonicus var. typicus Théel, 1886 : 161 , pl. VIII, fig. 2. Apostichopus japonicus : Liao, 1980 : 116 , fig. 1; Sun et al ., 2010 : 280 –285. Apostichopus armata [sic]: Kuramochi & Naganuma, 2010 : 50 , figs 1[2a, 2b]–3 [the ossicles in figs 2 and 3 were erroneously given under the name ‘ A. japonicus ’ on the figures]. Type material examined. Syntype MCZ HOL –741, Hakodate , Japan . Additional materials examined. NSMT –E7045A, Tateyama Bay , Chiba , 21 April 2011 ; NSMT –E7047A, Aburatsubo Bay , Kanagawa , 10 July 2011 , Y. Tamura ; NSMT –E7047F, Aburatsubo Bay , Kanagawa , 10 July 2011 , Y. Tamura ; NSMT –E7047C, Aburatsubo Bay , Kanagawa , 10 July 2011 , Y. Tamura ; NSMT –E7047E, Aburatsubo Bay , Kanagawa , 10 July 2011 . FIGURE 1. Syntype of Apostichopus armatus (Selenka, 1867) , MCZ HOL–741. Type locality. Hakodate [misspelled as Hakodadi by Selenka (1867) ], Japan. Description. Twenty peltate tentacles. Two rows of dorsal papillae, each arranged alternately in zig-zag pattern along dorso-lateral radius. Single row of conical papillae along each ventro-lateral radius. Numerous, loosely arranged, small papillae scattered on dorsal and lateral body. Ventral side flattened. Tube feet arranged in 5–6 rows in central ambulacral area, 4–5 rows in both lateral ambulacral areas. Interambulacra narrow. Oral opening subventral, surrounded by ring of small papillae. Dorsal and ventral body surfaces uniformly light green to yellowish in alcohol. Gonads in two tufts; one on each side of dorsal mesentery. Free-hanging tentacular ampullae 20 in number. Polian vesicle single, in various shapes and forms. Intestine connected to dorsal mesentery with rete mirabile. FIGURE 2. Spicules from the dorsal body wall of Apostichopus armatus (Selenka, 1867) . A, tables with pillars and spinuous disk, NSMT–E7047E; B, tables with pillars and spinuous disk, NSMT–E7047A; C, reduced tables with spinuous disk, NSMT– E7047A; D, reduced tables with spinuous disk and 3–4 perforations, NSMT–E7047A; E, reduced tables with smooth disk, NSMT–E7047E. FIGURE 3. Spicules from the papillae tips of Apostichopus armatus (Selenka, 1867) , NSMT–E7047C. A, reduced table; B–C, tables with pillars; D, elongated buttons; E–F, multiperforated plates; G, curved rods with smooth surfaces; H, straight, spiny rod. Dorsal body wall with tables. Disk of tables rounded to oval in shape with 2–16 irregular perforations; rim of disk spinous or smooth ( Fig. 2A–E ). Pillar of reduced tables entirely absent or forming only a knob ( Fig. 2C ). Tables usually having four pillars; tip of each pillar often branched into multiple spines ( Fig. 2A ). Papillae containing multiperforated plates, tables, rods and elongated buttons. Multiperforated plates in papillae with numerous irregular perforations; rim uneven ( Fig. 3E–F ). Tables in papillae similar to those in dorsal body; pillars absent or forming knobs; rim spinous ( Fig. 3A ); mostly four pillars present, each having single spine on tip ( Fig. 3B–C ). Elongated buttons in papillae having two parallel longitudinal rows, each with 7–13 perforations ( Fig. 3D ). Rods in papillae variable in shape from straight to curved; surface of curved rods smooth ( Fig. 3G ), surface of straight rods spinous ( Fig. 3H ). Tentacles containing rods; curved ( Fig. 4A–B ); surface covered with spinelets. Tube feet containing multiperforated plates ( Fig. 5A–B ). Cloacal wall containing oval to rounded complex plates; surface very spinous surface. Distribution. Shallow temperate waters in the coasts of China , Japan , Korea and Russia . Northern distribution limit at Sakhalin Island, Russia and Southern limit in the Kagoshima prefecture in Japan (see Zhao 2015 ). Remarks. Reduced tables are the dominant spicules in the dorsal body wall of A. armatus . They are similar to the spicules found in the type material of H. armata in which Selenka (1867) described as “Spärlich durchlöcherte plättchen” [sic] or sparsely perforated plates which he compared to the spicules found in Holothuria ( Halodeima ) floridana ( Pourtalès, 1851 ) ( Selenka 1867: fig. 49 ). However, Selenka (1867) did not include the details of both the rims in the platelet spicules, and figures for the spicules from the type material. It is unfortunate that we are also unable to determine the spicules from the type material in this study because they appeared to be absent or completely dissolved. Incidentally, Selenka’s (1867) H. armata is “schwarz” (black) coloured, which is clearly still visible upon examining the specimen ( Fig. 1 ), which now forms part of the diagnosis for A. armatus . FIGURE 4. Spicules from the tentacles of Apostichopus armatus (Selenka, 1867) , NSMT–E7047A. A, large curved rods with spinelets on surface; B, small curved rods with spinelets on surface. FIGURE 5. Spicules from the tube feet of Apostichopus armatus (Selenka, 1867) , NSMT–E7047A. A–B, multiperforated plates. Apostichopus armatus can be differentiated from A. japonicus by the absence of reduced table spicules with spinous rim in A. japonicus . Similar spinous reduced table spicules are also clearly illustrated in S. j. var. typicus by Théel (1886: pl. 8, fig. 2) , S. japonicus in Liao (1980: fig. 1) , and A. armata in Kuramochi and Naganuma (2010: fig. 2) , which all represents A. armatus . Although some reduced tables with smooth rim (similar to those found in the dorsal body of A. japonicus ) are also present in A. armatus , they are only present in small amount compared to the dominant number of spinous ones. Spicules from the papillae, tentacles and tube feet are similar to those of A. japonicus .