Apostichopus armatus
Creators: name: Woo, Sau Pinn
name: Ogawa, Akito
name: Tan, Shau Hwai
name: Yasin, Zulfigar
name: Kajihara, Hiroshi
name: Fujita, Toshihiko
Publisher: name: Zenodo
Year: 2017
Subjects: Biodiversity
Taxonomy
Animalia
Echinodermata
Holothuroidea
Aspidochirotida
Stichopodidae
Apostichopus
Apostichopus armatus

description: 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.
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.
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.
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.
description: Published as part of Woo, Sau Pinn, Ogawa, Akito, Tan, Shau Hwai, Yasin, Zulfigar, Kajihara, Hiroshi & Fujita, Toshihiko, 2017, A taxonomic revision of the genus Apostichopus (Holothuroidea: Stichopodidae) from Japan, pp. 121-135 in Zootaxa 4350 (1) on pages 123-127, DOI: 10.11646/zootaxa.4350.1.7, http://zenodo.org/record/1050945