Species Diversity 21: 151–159 25 November 2016 DOI: 10.12782/sd.21.2.151 Rediagnosis of Onigocia grandisquama (Actinopterygii: Perciformes: Platycephalidae) and Comparison with Congeners Hisashi Imamura1,2,3 1 Laboratory of Marine Biology and Biodiversity (Systematic Ichthyology), Faculty of Fisheries Sciences, Hokkaido University, 3-1-1 Minato-cho, Hakodate, Hokkaido 041-8611, Japan E-mail: [email protected] 2 Fisheries Science Center, Hokkaido University Museum, Hokkaido University, 3-1-1 Minato-cho, Hakodate 041-8611, Japan E-mail: [email protected] 3 Corresponding author (Received 16 May 2016; Accepted 9 July 2016) A platycephalid fish, Onigocia grandisquama (Regan, 1908) is rediagnosed based on 52 specimens, including the holo- type, from the Indo-West Pacific. Geographic variation in the species was recognized in the number of pectoral-fin rays, the first example of such variation in fin ray counts in the Platycephalidae. The species displays wide intraspecific variation in the numbers of lachrymal, preocular, suborbital, and pterotic spines, with values for the first two overlapping with those of the very similar Onigocia spinosa (Temminck and Schlegel, 1843), making it difficult to separate the two. Onigocia grandis- quama can be distinguished from O. spinosa, as well as from Onigocia macrocephala (Weber, 1913) and Onigocia macrolepis (Bleeker, 1854), which share with O. grandisquama an ocular flap on the posterior part of the eye, in lacking spines on the inner, middle, and/or outer ridges of the lachrymal. The generally greater number of pterotic spines also helps to separate O. grandisquama from its three congeners. Key Words: geographic variation, intraspecific variation, Onigocia spinosa. Introduction Materials and Methods Onigocia grandisquama was originally described by Counts and measurements were made according to Regan (1908) from a single specimen collected in the Imamura (2008). Measurements were made with calipers Amirante Islands (as Amirantes), Seychelles, in the west- to the nearest 0.1 mm. Terminology of head spines follows ern Indian Ocean (Fig. 1A, B). Although Imamura and Knapp et al. (2000). The inner, middle, and outer ridges of Sakashita (1997) and Imamura and McGrouther (2008) the lachrymal are three ridges on the anterior portion of redescribed the species, their studied materials were col- that bone, as defined by Imamura (2011). Institutional acro- lected from limited areas (the holotype and an additional nyms are from Sabaj Pérez (2014), except for the National specimen from the Gulf of Thailand for the former, and 13 Institute of Coastal Aquaculture, Thailand (NICA). Stan- specimens from Queensland, eastern Australia for the latter) dard and head lengths are abbreviated as SL and HL, respec- and its intraspecific variation remained poorly known. In tively. the present study 52 specimens of O. grandisquama from the Material examined. The following 52 specimens of O. Indo-West Pacific were examined, including the holotype grandisquama were studied. In the list they are provision- (Fig. 2). Wide intraspecific variation in four meristic char- ally divided into five regions for a comparison of geographic acters was found, reducing the utility of two of them for sep- variation among them (Fig. 2). arating this species from the very similar Onigocia spinosa Western Indian Ocean (12 specimens): BMNH (Temminck and Schlegel, 1843). The presence or absence of 1908.3.23.209, holotype, 54.4 mm SL, Amirante Islands, spines on the inner, middle, and outer ridges of the lachry- Seychelles; USNM 303744, 7 specimens, 52.6–68.7 mm SL, mal proved to be useful for this purpose, however. In this north of Mauritius (11°05.00′S, 62°02.00′E), 58–61 m depth, paper I provide a detailed account of the morphological 8 January 1989; USNM 346059, 4 specimens, 53.4–71.9 mm variation in the species, with special attention to taxonomic SL, off Somali coast, Somalia (10°00′N, 51°15′E), 59–61 m characters suitable for separating O. grandisquama from O. depth, 16 December 1964. spinosa and other congeners. Eastern Indian Ocean (7 specimens): NTM S. 11335-009, 62.7 mm SL, Pandjang Island, southwestern Sumbawa, Indo- nesia (08°29′S, 116°58′E), 22–30 m depth, 15 August 1982; NTM S. 14363-012, 75.7 mm SL, northwest of Bassett Smith © 2016 The Japanese Society of Systematic Zoology 152 Hisashi Imamura Shoal, Timor Sea (13°13′7″S, 125°14′52″E), 63 m depth, 12 January 2004; CSIRO H 6723-01, H 6723-04, 2 specimens, June 1996; WAM P. 28754.009, 58.1 mm SL, North West 75.7–91.4 mm SL, east of Bowling Green Bay, Queensland Shelf, Australia (19°57′S, 117°54′E), 22 April 1983; ZMA (19°15′S, 147°36′E), 30 m depth, 1 December 2003; QM I. 112437, 4 paralectotypes of Onigocia macrocephala (Weber, 23081, 71.8 mm SL, off Swan Reef, Queensland (21°13′S, 1913), 38.3–40.7 mm SL, Sapeh Strait, Indonesia, 69 m 150°43′E), 47 m depth, 16 September 1986; QM I. 36018, depth. 68.2 mm SL, north of Cape Bowling Green, Queensland Coral Sea (31 specimens): BPBM 33845, 66.7 mm SL, (19°05.1′S, 147°26.1′E), 33 m depth, 23 November 2003; Chesterfield Islands (20°40′9″S, 158°45′9″E), 76 m depth, QM I. 36851, 37.1 mm SL, Blackwood Channel, Queensland 22 August 1988; CSIRO H 6697-03, 2 specimens, 69.8– (11°49.5′S, 143°40.5′E), 4 February 2005; QM I. 37297, 78.3 mm SL, east of Lizard Island, Queensland (14°41′S, 3 specimens, 33.8–57.3 mm SL, north of Waining Reef, 145°35–34′E), 32 m depth, 19 November 2003; CSIRO H Queensland (14°26.1′S, 145°14.1′E), 9 February 2005; QM 6719-01, 2 specimens, 69.7–79.2 mm SL, east of Lizard Is- I. 37312, 70.9 mm SL, east of Chapman Island, Queensland land, Queensland (14°40′S, 145°32′E), 28 m depth, 19 (12°53.7′S, 143°45.3′E), 26 January 2005; QM I. 37414, November 2003; CSIRO H 6722-01, 52.1 mm SL, north- 71.2 mm SL, Black Rock Entrance, Queensland (12°14.7′S, east of Cape York Peninsula, Torres Strait, Queensland 143°48.9′E), 7 February 2005; QM I. 37419, 69.5 mm (10°31′S, 143°51′E–10°32′S, 143°51′E), 27 m depth, 10 SL, northeast of Hadge Reef, Queensland (13°43.5′S, Fig. 1. Onigocia grandisquama. A–B, BMNH 1860.3.19.270, collected from the Amirante Islands, Seychelles, western Indian Ocean; C–D, QM I. 37419, 69.5 mm SL, collected from northeast of Hadge Reef, Queensland. A and C, dorsal views; B and D, lateral views. Rediagnosis of Onigocia grandisquama 153 Fig. 2. Map showing collection localities of 52 examined specimens of Onigocia grandisquama. Blue, western Indian Ocean; red, eastern Indian Ocean; yellow, Coral Sea; pink, Ceram Sea; green, Gulf of Thailand. The arrow indicates the holotype. 144°7.5′E), 35 m depth, 18 January 2005; other one AMS material; Amirante Islands, Mauritius, and Somalia, west- and 12 QM specimens from Queensland were listed in ern Indian Ocean); Manilo and Bogorodsky 2003: S103 Imamura and McGrouther (2008). (list, Arabian Sea); Imamura and McGrouther 2008: 239, Ceram Sea (1 specimen): ZMA 124954, paralectotype of figs 1–2 (redescription, Queensland, eastern Australia); Onigocia sibogae Imamura, 2011, 40.2 mm SL, northwest of Imamura 2011: 59 (list of comparative material; Ceram New Guinea (1°42.5′S, 130°47.5′E), 32 m depth. Sea, Mauritius, and Somalia); Imamura 2012: 30 (list of Gulf of Thailand (1 specimen): NICA 242, 61.7 mm SL, comparative material; Sapeh Strait, Indonesia). Songkhla, 1982. Diagnosis. A species of the genus Onigocia Jordan and Comparative material. Other specimens of Onigocia, in- Thompson, 1913 with the following characters: first dorsal- cluding type specimens of each species except for O. macro- fin rays I+VII–VIII (usually I+VIII); second dorsal-fin rays lepis which lacks extant types, are in the collections of AMS, 10–11 (usually 11); anal-fin rays 11–12 (usually 11); pecto- BMNH, BPBM, CMNH, CSIRO, HUMZ, MNHN, NICA, ral-fin rays 19–22; branched caudal-fin rays 9–10; pored lat- NSMT, NTM, QM, RMNH, USNM, WAM and ZMA, as eral-line scales 32–39, anterior 2–8 scales each with a spine; listed in Imamura and Knapp (2009) and Imamura (2011, gill rakers 1+4–5=5–6; lachrymal spines 2–5 (usually 2), 2012). tending to increase in number with growth; inner, middle, and outer ridges on lachrymal lacking spines; preocular Onigocia grandisquama (Regan, 1908) spines 1–6, tending to increase in number with growth; sub- (Figs 1, 4; Tables 1–3) orbital spines 14–30, tending to increase in number with growth; pterotic spines 2–11, tending to increase in number Platycephalus grandisquamis Regan, 1908: 239 (original with growth; HL 41.6–45.6% SL, single ocular flap present description; type locality: Amirante Islands, Seychelles, on posterior part of eye, not extending to its posterior mar- western Indian Ocean). gin; small, short papillae absent on posteromedial part of Platycephalus macrocephalus Weber, 1913: 508, fig. 107 eye; upper iris lappet short and branched; notch absent on (original description; type locality: Sapeh Strait, Indone- suborbital ridge below eye; interopercular flap absent; pelvic sia) (in part); de Beaufort and Briggs 1962: 146, fig. 36 fin brownish to blackish, lacking distinct spots. (description; Sapeh Strait, Indonesia) (in part). Distribution. Onigocia grandisquama has been record- Platycephalus grandisquamis Weber, 1913: 509, fig. 108 ed widely in the Indo-West Pacific, including the Amirante [original description; type locality: northwest of New Islands, Seychelles (type locality; Regan 1908), Mauritius Guinea (1°42.5′S, 130°47.5′E)] (in part).