Species Diversity 21: 31–42 25 May 2016 DOI: 10.12782/sd.21.1.031 Octopus sinensis d’Orbigny, 1841 (Cephalopoda: Octopodidae): Valid Species Name for the Commercially Valuable East Asian Common Octopus Ian G. Gleadall International Fisheries Science Unit, Tohoku University Graduate School of Agricultural Science, 1-1 Amamiya, Sendai, Miyagi 981-8555, Japan E-mail: [email protected] (Received 21 July 2015; accepted 12 May 2016) http://zoobank.org/34118987-F3F3-4FEA-BD74-03218965CF84 The East Asian common octopus has long been synonymized with the Atlantic and Mediterranean species Octopus vulgaris Cuvier, 1797. However, evidence from molecular genetic studies has firmly established that the so-called cosmo- politan common octopus is in fact a group of several biogeographically distinct populations which form a complex of spe- cies with closely similar morphology. Here, a diagnosis and brief description are provided which distinguish the East Asian common octopus from O. vulgaris, and as a suitable name for it a former junior synonym of O. vulgaris is identified as a valid species: Octopus sinensis d’Orbigny, 1841. A neotype is designated. Voucher material includes specimens collected in Japan by Philipp Franz von Siebold and deposited in the National Museum of Natural History - Naturalis - in Leiden; and others that were studied by Madoka Sasaki in preparation for the detailed description of this species (as O. vulgaris) in a monograph on Japanese Cephalopoda published in 1929. At present, all species in this complex (particularly O. vulgaris and the East Asian species here identified as O. sinensis) are highly vulnerable to overfishing, so recognizing O. sinensis as a species distinct from O. vulgaris is an important step towards improving sustainable fisheries management policies for each species in this group of commercially valuable octopuses. Key Words: hectocotylus, Octopus sinensis, Octopus vulgaris, arm length, suckers. Octopus insularis Leite and Haimovici in Leite, Haimovici, Introduction Molina and Warnke, 2008 (q.v.). There is no extant type material for O. vulgaris (first de- Octopus is the most familiar and widely used genus name scribed from Europe) and the species has never been de- for octopus species but its taxonomy has had a confusing scribed in sufficient detail to allow recognition of any small history and the names of both the genus and its type spe- differences from populations in other parts of the world. cies, O. vulgaris Cuvier, 1797, were stabilized only relatively Indeed, its widely known presence appears to have resulted recently (ICZN 1954, 1997). Octopus vulgaris is best known in a lack of interest in preserving specimens of this species as an Atlantic and Mediterranean species but this name has of sufficient maturity and quality for systematic study (pers. long been associated also with the East Asian common octo- obs.). Until this century, therefore, despite being a common pus from Japanese waters, since it was thought to be just one species there have been few preserved specimens available species with a cosmopolitan distribution. This was also the for morphological comparisons of O. vulgaris and the East conclusion of Sasaki (1929) in his monograph on the Ceph- Asian common octopus. However, Guerra et al. (2010) have alopoda of Japanese waters, which has been supported even recently reported morphological measurements for repre- by studies early this century using molecular genetic analy- sentative specimens of O. vulgaris to complement their ge- sis (e.g., Warnke et al. 2004; Kaneko et al. 2011). netic analysis. Recent studies of aquaculture techniques for However, more recent molecular genetic analyses (e.g., the East Asian common octopus in Japan have provided the Guerra et al. 2010; Amor et al. 2014) have revealed conclu- opportunity to acquire a range of new specimens sufficient sively that this apparently cosmopolitan species is in fact a for comparison with the Mediterranean-Atlantic form. This species complex, with as many as five distinct species of “O. comparison here reveals clear morphological and meristic vulgaris” in the Atlantic alone. Within this species complex, differences between the East Asian common octopus and in the western North Pacific the East Asian common oc- O. vulgaris which, together with the evidence available from topus forms a distinct genetic clade that differs from other genetic analysis, confirm that these two forms are different members of this complex at the species level (Guerra et al. species. Here, the species name Octopus sinensis d’Orbigny, 2010; Amor et al. 2014). Most species in this complex have 1841 (previously judged to be a synonym of O. vulgaris; see, yet to be distinguished using morphological and meristic for example, Sasaki 1929), is reinstated as the appropriate characters, although recently one of the Atlantic popula- valid name for the East Asian common octopus. tions off Brazil has been well described as the new species © 2016 The Japanese Society of Systematic Zoology 32 Ian G. Gleadall fication: subsequently identified by Sasaki 1929: 37). Materials and Methods Octopus vulgaris (non Cuvier, 1797): Appellöf 1886: 7; Ort- mann 1888: 642; Robson 1929: 57 (in part); Nesis 1987: New specimens of Octopus sinensis were obtained as part 312 (in part; northwestern Pacific population); Okutani of a research project to develop aquaculture methods for et al. 1987: 157, fig. 60 A–C; Kaneko et al. 2011: 106; Ku- the East Asian common octopus. They were fixed in 10% bodera 2013: 212. formalin in seawater. Small pieces of arm muscle were first Polypus vulgaris: Wülker 1910: 5; Berry 1912: 386; Sasaki removed and preserved in absolute ethanol for molecular 1929: 35 (in part), text figs 11–12, pl. IV fig. 1, pl. IX figs analysis. After about a month, the specimens in formalin 1–3, pl. XXIX fig. 1. (Polypus is a suppressed name; ICZN were thoroughly rinsed in running tap water and preserved 1954). in 45% isopropanol. Specimens collected previously and de- Octopus cf. vulgaris (cf. O. sinensis): Gleadall and Salcedo- posited in other institutions were inspected and those iden- Vargas 2004: 119 (in part). tified as O. sinensis are included in the redescription. Meth- ods for measurements and for counting of meristic charac- Material examined. Neotype, here designated, mature ters follow Gleadall et al. (2010). All dimensions are in mm. male (ML 97 mm), Ariake Sea, Hato-no-kama Harbour, For comparison, a search was made for specimens of O. Oyano Is., Kami-amakusa City, Kumamoto Pref., Kyushu, vulgaris in good condition from recorded localities in muse- Japan, IGG 312, NSMT Mo 85659, 25.x.2013, M. Abe, I.G. um collections (listed at the end of the text), and comparisons Gleadall, K. Matsubara and S. Morii. were made also with data reported by Guerra et al. (2010). Other material examined: 1 mature male (ML 95 mm), The specimens used by Guerra et al. (2010) were, as in the loc. not stated (?Kyushu, Japan), NRML 2438, undated present study, measured following preservation. However, (?1824–1827), P.F. von Siebold; 1 immature female (ML they are now no longer extant, having been donated to the 89 mm), loc. not stated (?Kyushu, Japan), NRML 472, un- Luarca Museum on the northwestern coast of Spain, but then dated (?1824–1827), P.F. von Siebold; 1 submature male (ML lost when that museum was tragically devastated by a power- 107 mm), Kagoshima, Kyushu, Japan, ZUMT 994.CO-38 ful storm on 5 February, 2014 (A. Guerra, pers. comm.). [056], August 1903, donated by Kagoshima Prefectural Gov- Abbreviations: Arms no. 1–4, arms counted in corre- ernment; 1 male ML 106 mm (head dissected, arms miss- sponding left (L) and right (R) pairs from the dorsal to the ing), 1 submature female ML 119 mm (no collection data), ventral midline of the head (arms identified individually as ZUMT 994.CO-20 [058]; 1 submature female (ML 84 mm), L1, R3, etc.); #, number prefix indicating the position of the 1 juv. (ML 35 mm), Japan Sea, off Konoura, Yuri-gun, south- largest suckers on an arm, counting distally from the mouth; ern Akita Pref., Honshu, Japan, NSMT Mo 75758 (SHC), 17 BMNH, (British) Natural History Museum, London; CO1, October 1931; 1 male (ML 96 mm), Onahama, Iwaki-gun, Cytochrome C oxidase subunit 1; CO3, CO subunit 3; ICM, Fukushima Pref., Honshu, Japan, NSMT Mo 75750 (SHC), Instituto de Ciencias del Mar, Barcelona; ICZN, Internation- January 1932; 2 males (ML 82, 68 mm), Pacific Ocean, Send- al Commission on Zoological Nomenclature; IGG, lot pre- ai Bay, off Yuriage, Natori-gun, Miyagi Pref., Honshu, Japan, fix of specimens fixed and preserved by the author (as indi- NSMT Mo 75759 (SHC), January 1933; 1 immature male cated below, lots IGG 290, 307 and 309 are included among (ML 42 mm), Pacific Ocean, off Hayama, Sagami (Kanagawa specimens donated to Michael Amor, at La Trobe Univer- Pref.), Honshu, Japan, SMI 051, 8 June 1957; 1 male (ML sity, Melbourne, Australia, towards his study on the Octopus 56 mm), Japan Sea, Fukaura, Nishitsugaru-gun, Aomori vulgaris species complex); juv., juvenile; loc., locality; ML, Pref., Honshu, Japan, NSMT Mo 75739 (SHC), August 1963; dorsal mantle length; NRML, National Museum of Natural 1 male (ML 72 mm), Japan Sea, Kamo Aquarium (original- History - Naturalis, Leiden; NSMT, National Museum of ly caught by octopus pot), Yamagata Pref., Honshu, Japan, Nature and Science, Tsukuba; pers. comm., personal com- BMNH 1994108, Sept. 1987, I.G. Gleadall; 1 mature female munication; pers. obs., personal observation; Pref., Prefec- (ML 122 mm), Japan Sea, Toyama Bay, Uozu, (octopus pot), ture; SHC, Saitō Hō-onkai Collection (the collection of the Toyama Pref., Honshu, Japan, IGG 036, NSMT Mo 85656, Zenuemon Saito Gratitude Foundation, formerly in Sendai, August 1992, O. Inamura; 1 mature male (ML 93 mm), all specimens of which were donated to NSMT; now part Shiriyazaki, Pacific coast of Aomori, IGG 039, NSMT Mo of the NSMT collections); SMI, Shōwa Memorial Institute, 85657, 22 March 1993, I.G.