Enneapterygius minutus ( Günther, 1877 )

Dewa, Yuna, Tashiro, Satokuni & Motomura, Hiroyuki, 2023, A new species of the genus Enneapterygius (Perciformes: Tripterygiidae) from Japan and the Philippines, with a synopsis and synonymy of related species, Zootaxa 5374 (3), pp. 333-360 : 344-349

Enneapterygius minutus ( Günther, 1877)

[English name: Minute Triplefin; standard Japanese name: Kusa-gimpo]

Figures 4–6 , 8–10 ; Tables 3 , 6 , 7

Tripterygium minutum Günther, 1877: 211 , pl. 118D (original description; type locality: Apia , Upolu Island, Western Samoa).

Enneapterygius minutus : Jordan & Seale, 1906: 416 [Apia, Western Samoa (based on Günther, 1877)]; Myers, 1991: 204, unnumbered fig. ( Vanuatu; Ryukyu, Mariana, Marshall, Salmoan, and Phoenix islands); Hayashi, 1993: 946, unnumbered figs. (Ryukyu Islands; western Pacific); Shen, 1994: 14, fig. 9A, B (Liu-chiu, Taiwan); Fricke, 1994: 242, fig. 46 (western Indian Ocean; western Pacific Ocean: Philippines; Indonesia; Christmas Island; Western Australia, Northern Territory, and Queensland, Australia; Belau; Kiribati; New Caledonia; Vanuatu; Fiji; Tonga; Niue; American Samoa); Hayashi, 2000: 1081, unnumbered figs. (Ryukyu Islands; western Pacific).

Enneapterygius tusitalae Jordan & Seale, 1906: 416, fig. 97 (type locality: Apia, Western Samoa); Snyder, 1912: 447 (Tanega-shima island, Japan); Jordan et al., 1913: 379 (Tanega-shima island, Japan; Samoa).

Enneapterygius pardochir Jordan & Seale, 1906: 417, fig. 98 (type locality: Apia, Western Samoa).

Enneapterygius punctulatus Herre, 1935: 432 (type locality: Malo Island , New Hebrides Islands, Vanuatu).

Enneapterygius philippinus (not of Peters, 1868): Jordan & Richardson, 1904: 283 (Calayan, Philippines); Fricke, 1997: 274, fig. 58 (Indo-West Pacific Ocean); Hayashi, 2002: 1081, unnumbered figs (Ryukyu Islands; Indo-West Pacific); Randall, 2005: 473, unnumbered fig. ( Marshall Islands); Chiang & Chen, 2008: 197, fig. 4j, k (Taiwan); Imamura, 2009: 243, unnumbered figs (Andaman Sea); Motomura et al., 2010: 184, fig. 427 (Yaku-shima island, Japan); Allen & Erdmann, 2012: 769, unnumbered figs ( Palau and Christmas Island); Hayashi, 2013: 1284, unnumbered figs (Yaku-shima, Tanega-shima, Yoron-jima, Ie-jima, and Iriomote-jima islands; southern Taiwan; Indo-West Pacific, east to Mascarene, Caroline, Marshall, and Gilbert islands); Tashiro, 2014: 450, unnumbered figs (Yoron-jima island, Japan); Kimura et al., 2017: 151 fig. 5 (Kuchinoerabu-jima island, Japan); Mochida & Motomura, 2018: 47 (Tokuno-shima island); Tashiro, 2019: 301, unnumbered figs (Amami-oshima and Yoron-jima islands); Motomura & Uehara, 2020: 73 (Okinoerabu-jima island, Japan); Tashiro, 2021: 60, unnumbered fig. (Bidong Island, Malaysia); Holleman, 2022: 417, unnumbered figs (northern Mozambique and Mauritius).

Enneapterygius nanus (not of Schultz, 1960): Shen, 1994: 16, fig. 10 (Wan-li-Tung, Taiwan).

Lectotype. BMNH 1961.10.20.1 , female, 20.4 mm SL, Apia , Western Samoa, 1872.

Paralectotype. BMNH 1873.4.3.218 , female, 18.8 mm SL, same data as lectotype .

Other type specimens. 7 specimens (17.1–23.0 mm SL). FMNH 17388 , holotype of Enneapterygius punctulatus , male, 20.8 mm SL, Wala Island , Vanuatu, 29 Ma. 1929, A. Herre; USNM 51799 , holotype of Enneapterygius pardochir , male, 21.2 mm SL, Apia , Upolo Island, Samoa, summer of 1902, D. Jordan & V. Kellogg; USNM 51800 , holotype of Enneapterygius tusitalae , male, 18.5 mm SL, same data as USNM 51799; ZMA 112.501 , 2 paralectotypes of Tripterygium callionymi , females, 23.0–25.0 mm, Pidjot Bay , Lombok Island, Indonesia, 9–22 m, 24–26 Mar. 1899, M. Weber; ZMA 112.503 , 1 of 2 paralectotypes of Tripterygium callionymi , male, 21.7 mm SL, east coast of Sulawesi, Indonesia, 13–14 Sept. 1899, M. Weber; ZMB 32768 , paralectotype of Enneapterygius philippinus , female, 18.8 mm SL, eastern end of Luzon , Philippines, Oct. 1859, F. Jagor .

Non-type specimens. 100 specimens (12.7–29.7 mm SL). MADAGASCAR: AMS I. 28108-034 , 4 males and 3 females, 12.7–18.1 mm SL, rocky point, 2 km west of a hotel, Andilana Beach , Nosy-Be Island, 14°43′15″S, 50°56′15″E, 6 Nov. 1988, J. Paxton et al. MASCARENE ISLANDS: USNM 343960 , female, 18.4 mm SL, tidepools below Lighthouse , Point Aux Caves , Mauritius, 0–1 m, 3 May 1995, P. Heemstra et al . JAPAN: OSUMI ISLANDS: Tanega-shima island : KAUM–I. 5777 , male, 23.1 mm SL, KAUM–I. 5783 , male, 26.6 mm SL, Kishikazaki , Nishinoomote, 30°50′22″N, 131°03′22″E, 0.5 m, 11 Aug. 2007, M. Meguro. Yaku-shima island: CMNH-ZF14072 , male, 20.4 mm SL, Shitoko , Kamiyaku , 30°26′43″N, 130°31′22″E, 27 Oct. 2015, K. Sakamoto; KAUM–I. 21823 , female, 29.5 mm SL, KAUM–I. 21824 , male, 28.5 mm SL, KAUM–I. 21836 , female, 29.7 mm SL, west of Kamazenohana, Kurio , 30°16′03″N, 130°24′48″E, 0–4 m, 30 July 2009, KAUM Fish Team; KPM-NI 22764 , male, 29.4 mm SL, Harutahama , 31 May 2008, A. Murase. TOKARA ISLANDS: Taira-jima island: KAUM–I. 86924 , female, 22.3 mm SL, KAUM–I. 86925 , male, 24.3 mm SL, Haenohama Port , 29°40′47″N, 129°31′55″E, 1 m, 23 Apr. 2016, M. Matsuoka. Takara-jima island: KAUM–I. 176191** , male, 19.8 mm SL, KAUM–I. 176192** , male, 18.5 mm SL, KAUM–I. 176303** , female, 20.1 mm SL, KAUM–I. 176304 **, female, 17.3 mm SL, Okago Beach , 29°09′29″N, 129°12′58″E, 0.1–1 m, 25 Oct. 2022, Furuhashi et al. AMAMI ISLANDS: Amami-oshima island: CMNH-ZF 6551 , male, 24.8 mm SL, Ayamaruzaki, Kasari , 28°28′20″N, 129°43′19″E, 14 July 2003, M. Aizawa; CMNH-ZF 11336 , male, 19.1 mm SL, Setta, Kasari , 28°24′36″N, 129°41′43″E, 6 July 2004, Y. Ikeda & M. Aizawa; KAUM–I. 17531 , male, 24.5 mm SL, KAUM–I. 17532 , male, 23.7 mm SL, tidepool at Ushuku, Kasari , 28°26′38″N, 129°43′10″E, 0.5–1 m, 28 Mar. 2009, M. Meguro & T. Yoshida; KAUM–I. 17552 , female, 23.9 mm SL, Tomori Beach, Kasari , 28°27′48″N, 129°43′08″E, 0.5–1 m, 29 Mar. 2009, M. Meguro & T. Yoshida. Tokunoshima island: KAUM–I. 143740 , male, 20.7 mm SL, KAUM–I. 143741 , female, 23.3 mm SL, KAUM–I. 143742 , female, 21.3 mm SL, tide pool at Kenbuku, Isen , 27°39′57″N, 128°57′35″E, 0.5 m, 2 July 2020, T. Yoshida et al. Okinoerabu-jima island: KAUM–I. 159872 , female, 15.0 mm SL, KAUM–I. 159873 , male, 19.1 mm SL, Kasaichi Beach , Kibiru , Wadomari , 27°24′36″N, 128°40′23″E, 0.5 m, 23 Aug. 2021, T. Iino & Y. Dewa. Yoron-jima island: KAUM–I. 45923 , male, 23.6 mm SL, KAUM–I. 45924 , male, 23.8 mm SL, KAUM–I. 45925 , male, 23.5 mm SL, KAUM–I. 45926 , male, 25.6 mm SL, KAUM–I. 45927 , male, 22.9 mm SL, tidepool at Chabana , 27°03′40″N, 128°25′02″E, 0.5 m, 18 Apr. 2012, S. Tashiro et al.; KAUM–I. 46133 , male, 23.8 mm SL, KAUM–I. 46135 , male, 21.4 mm SL, KAUM–I. 46138 , female, 22.3 mm SL, KAUM–I. 46141 , male, 23.4 mm SL, KAUM–I. 46144 , male, 22.2 mm SL, KAUM–I. 46145 , male, 24.3 mm SL, KAUM–I. 46146 , male, 24.4 mm SL, KAUM–I. 46147 , male, 25.4 mm SL, KAUM–I. 46148 , male, 22.2 mm SL, same data as KAUM–I. 45923, 21 Apr. 2012; KAUM–I. 50849 , male, 20.2 mm SL, same data as KAUM–I. 45923, 3 m, 20 Aug. 2012, KAUM Fish Team. OKINAWA ISLANDS: Noho-jima island : KAUM–I. 41323 , male, 23.1 mm SL, west of island, 27°02′24″N, 127°54′48″E, 0.5–2 m, 9 Mar. 2011, H. Nishiyama & H. Yamauchi. Ie-jima island: KPM-NI 10809 , male, 20.9 mm SL, tidepool, 1 Aug. 2002, T. Nomura. Okinawa-jima island: KAUM–I. 28545 , male, 26.3 mm SL, KAUM–I. 28547 , male, 25.0 mm SL, KAUM–I. 28549 , female, 23.3 mm SL, KAUM–I. 28566 , male, 22.2 mm SL, Minatogawa, Urasoe , 26°16′35″N, 127°42′06″E, 1 m, 14 Apr. 2010, M. Meguro. Tokashiki-jima island: KPM-NI 16896 , female, 24.5 mm SL, south of Tokashiku Beach , 5 Mar. 2003, Association for Study of Aquatic Organisms. KPM-NI 22672 , female, 20.1 mm SL, south of Tokashiku Beach , 4 Mar. 2007, H. Fujioka; KPM-NI 22679 , male, 22.5 mm SL, KPM-NI 22682 , female, 22.0 mm SL, same data as KPM-NI 22672, 16 Nov. 2008 . YAEYAMA ISLANDS: Ishigaki-jima island: KAUM–I. 53874 , female, 21.8 mm SL, tidepool at Kabira , 24°26′57″N, 124°10′41″E, 1 m, 9 Apr. 2014, T. Yoshida & H. Nishiyama; KAUM–I. 62851, female, 21.4 mm SL, KAUM–I. 62853 , male, 19.5 mm SL, same data as KAUM–I. 53874, 0.5–2 m, 14 July 2014, T. Yoshida & S. Tashiro. Iriomote-jima island: CMNH-ZF 11822 , male, 18.9 mm SL, off Hoshitate , Taketomi , 24°23′16″N, 123°45′09″E, 30 Sept. 2004, K. Sakamoto & T. Kamisato. TAIWAN: KAUM–I. 39267 , male, 18.8 mm SL, Wan Li Tong, Kenting , Pingdong, 21°59′52″N, 120°42′03″E, 0.5 m, 3 July 2011, M. Meguro. CHINA: NSMT-P 54786 , 1 male and 2 females, 22.1–24.1 mm SL, Dadonghai, south coast of Hainan Island, 6 m; NSMT-P 59989 , female, 22.4 mm SL, Dadonghai , south coast of Hainan Island , 5–8 m. PHILIPPINES: USNM 137875 , male, 18.6 mm SL, Sablayan , Mindoro Island , 13 Dec. 1908, Albatross; USNM 259150 , 2 females, 17.7–22.7 mm SL, southern tip of Negros Island , 09°03′N, 123°07′E, 12 May 1978, V. Springer & L. Knapp; USNM 259151 , female, 24.4 mm SL, Siquijor Island, 10 May 1978, V. Springer et al.; USNM 317988 , male, 18.4 mm SL, middle of south coast of Fuga Island, Babuyan Island Group, 18°51′N, 121°22′E, 11 Mar. 1990, C. Ross & V. Samarira. THAILAND: NSMT-P 55360 , male, 20.3 mm SL, Nai Yang Beach, Phuket; NSMT-P 70890 , male, 19.6 mm SL, Ko Lacha Yai , Phuket. PAPUA NEW GUINEA: USNM 259164 , male, 21.9 mm SL, Meman Island , Ninigo Islands , 01°12′40″S, 144°16′59″E, 27 Oct. 1978, V. Springer et al. AUSTRALIA: AMSI. 18339-004 , 5 males and 1 female, 21.3–25.7 mm SL, west slope of One Tree Island , Queensland, 23°30′S, 152°05′E, 21 Oct. 1973 . MARSHALL ISLANDS: NSMT-P 62003 , male, 14.9 mm SL, lagoon side, 14.5 km from Laura Village , Majuro Atoll, 4 Aug. 1982 . GILBERT ISLANDS: AMS I. 18049-011 , 3 males and 2 females, 17.0– 19.0 mm SL, 100 m north of Tebunginako, Abaiang Atoll , 01°49′N, 173°02′E, 9 Nov. 1973, D. Hoese. SOLOMON ISLANDS: ANSP 95501 , male, 16.9 mm SL, Rennell Island , 20 Aug. 1953, E. Laird. VANUATU: USNM 359498 , male, 21.5 mm SL, southeast side of Efate Island , 17°49′23″S, 168°25′00″E, 6 May 1997, J. Williams & D. Smith; ANSP 100157 , male and female, 15.4–20.4 mm SL, New Hebrides, 1953, M. Laird; ANSP 105253 , male, 19.2 mm SL, Anelganket, Aneityum Island , 1953, E. Laird & M. Laird. NEW CALEDONIA: USNM 259132 , 4 males, 14.9–23.4 mm SL, 29 July 1983, W. Chapman. FIJI: USNM 330367 , male, 22.4 mm SL, Ono Ilau, Yanutha Islet, Lau Group , 29 Apr. 1982, V. Springer et al. AMRICAN SAMOA: ANSP 50989 , 5 males, 16.4–18.7 mm SL, Pago Pago Harbor, Tutuila , 8 Apr. 1917 .

Diagnosis. A species of Enneapterygius ( Fig. 9 ) with the following combination of characters: 10–13 (modally 11) second dorsal-fin spines; 7–10 (9) third dorsal-fin rays; I, 15–17 (16) anal-fin rays; i–v (iii) + 3–7 (5) + vi–viii (vii) = 13–16 (15) pectoral-fin rays (iii + 5 + vii = 15 in 30 specimens, iii + 5 + vi = 14 in 17 specimens, ii + 5 + vii = 14 and iv + 4 + vii = 15 in 5 specimens, i + 7 + vii = 15 and ii + 6 + vi = 14 in 5 specimens, ii + 7 + vi =15 and iv + 4 + vi = 14 in 3 specimens, ii + 6 + vii = 15, iii + 4 + vii = 14, and v + 3 + vii = 15 in 2 specimens, and 8 + vii = 15, ii + 6 + viii = 16, iii + 5 + v = 13, and iii + 4 + viii = 15 in single specimens only); 11–15 (13) pored lateral-line scales; 17–22 (20) notched lateral-line scales; 29–34 (32) scale rows in longitudinal series; 1–3 (1) scales above 1st pored lateral-line scale; 2–4 (3) scales below 1st notched lateral-line scale; 8 circumpeduncular scales; mandibular pore formula 2–4 + 1 + 1–4 (usually 3 + 1 + 3) (3 + 1 + 3 in lectotype, paralectotype, and 80 non-type specimens, 2 + 1 + 2 and 4 + 1 + 4 in 2 specimens, and 3 + 1 + 1, 3 + 1 + 2, and 4 + 1 + 3 in single specimens only) ( Fig. 8B ); head short, its length 24.7–32.4% (mean 28.6%) of SL; upper jaw short, its length 7.4–11.0% (9.6%) of SL; 1st spine of first dorsal fin shorter than that of 2nd dorsal-fin, its length 7.6–11.4% (8.7%) of SL; anterior nostril tentacle unbranched; orbital tentacle slender, pointed distally, its length less than or subequal to half of pupil diameter; head (except for nape and upper half of opercle), body, and pectoral, pelvic, and caudal fins black in nuptial males, particularly dark on lower half of head, and pectoral and caudal fins ( Fig. 9A–C ); membranes of all dorsal fins and anal fin grayish with yellow or orange pigmentation; body generally yellowish-white, with scattered brownish-orange pigmentation, particularly along scale margins, darker on lateral surface forming indistinct A-shaped bars in pale males and females ( Fig. 9D–F ); pectoral-fin rays distinctly flecked with brown pigmentation, forming ca. 4 or 5 narrow vertical bands on fin; no distinct oblique lines on anal-fin membranes.

Distribution. Currently considered widespread in the Indo-Pacific region, including the Mascarene Islands ( Mauritius), Madagascar and Mozambique ( Fricke, 1994, 1997; Holleman, 2022). In the western Pacific Ocean, E. minutus has been recorded from the following localities: Ryukyu Islands ( Snyder, 1912; Jordan et al., 1913; Hayashi, 1993, 2000, 2013; Motomura et al., 2010; Tashiro, 2014; Kimura et al., 2017; Mochida & Motomura, 2018; and Motomura & Uehara, 2020); Taiwan [Chenggong, southeast coast of Taiwan; Pingdong and Wan-li-tung, southwest coast of Taiwan; Liu-chiu ( Shen, 1994; Chiang & Chen, 2008)]; China (Hainan Island); the Philippines [Calayan, Fuga, Mindoro, Negros, and Siquijor islands ( Jordan and Richardson, 1904; Fricke, 1994)]; Mariana Islands ( Myers, 1991); Palau ( Randall, 2005); Thailand [Phuket, Andaman Sea ( Imamura, 2009)]; Malaysia [Bidong Island ( Tashiro, 2021)]; Indonesia ( Fricke, 1997; this study); Papua New Guinea (Meman Island); Australia [ Christmas Island; Western Australia, Northern Territory, and Queensland ( Fricke, 1994, 1997; Allen & Erdmann, 2012)]; Marshall Islands [Majuro Atoll ( Myers, 1991; Randall, 2005)]; Gilbert Islands; Solomon Islands [Rennell Island ( Myers, 1991)]; Vanuatu [ New Hebrides Islands ( Herre, 1935; Myers, 1991; Fricke, 1994)]; New Caledonia; Fiji; Samoa [Upolu and Pago Pago Islands ( Günther, 1877; Jordan & Seale, 1906; Fricke, 1994)]; Kiribati ( Myers, 1991; Fricke, 1994). ( Fig. 4 ).

Remarks. Enneapterygius minutus ( Günther, 1877) was originally described as Tripterygium minutum on the basis of two specimens from Apia, Western Samoa, and regarded as a valid species of the genus Enneapterygius by Jordan & Seale (1906). Subsequently, Fricke (1994) redescribed E. minutus on the basis of 396 specimens, with the designation of a lectotype (BMNH 1961.10.20.1, female, 20.4 mm SL; Fig. 10A ) for the species. In addition, Fricke (1994) regarded the following six nominal species as junior synonyms of E. minutus , viz., Enneapterygius cerasinus Jordan & Seale, 1906, Enneapterygius pardochir Jordan & Seale, 1906, Enneapterygius tusitalae Jordan & Seale, 1906, Tripterygium callionymi Weber, 1909 , Enneapterygius punctulatus Herre, 1935 , and Enneapterygius waigiensis Herre, 1935 . He later ( Fricke, 1997) proposed E. minutus and the above six nominal names as junior synonyms of Enneapterygius philippinus (Peters, 1896) , in addition to Enneapterygius fuligicauda Fowler, 1946 , bringing to eight the number of nominal species synonymized with E. philippinus .

Re-examination of the type and non-type specimens of E. philippinus , and all of the nominal species synonymized by Fricke (1997) during the present study revealed that E. minutus , redescribed herein as a valid species, could be distinguished from other species of Enneapterygius , including E. philippinus , by meristic and morphometric characters, and coloration pattern (See E. philippinus Remarks.). In addition, E. tusitalae , E. pardochir , and E. punctulatus are regarded as junior synonyms of E. minutus in this study, as the meristics and measurements of the holotypes of the former three species closely matching those of the lectotype, paralectotype, and 96 non-type specimens of the latter ( Fig. 10 ; Table 3 ).

Tripterygium callionymi was originally described from Indonesia (Celebes and Banda seas) on the basis of eight syntypes. Subsequently, Fricke (1997) re-examined the type series, identifying six of the eight syntypes as E. philippinus , and designating ZMA 112.506, collected from eastern Sulawesi, as the lectotype of T. callionymi , which he regarded as a junior synonym of E. philippinus . However, the lectotype of T. callionymi (ZMA 112.506; Fig. 11A ), re-examined in this study, clearly differed from E. philippinus by having 2 + 2 + 2 mandibular pores (vs. mandibular pore formula 3 + 2 + 3 in E. philippinus ) and unbranched pectoral-fin rays (vs. 4–7 rays branched). Tripterygium callionymi is more likely to be a junior synonym of Enneapterygius tutuilae Jordan & Seale, 1906, since the above mentioned characters of the T. callionymi lectotype closely matched those of E. tutuilae provided by Fricke (1997) and Tashiro (2019). Furthermore, although Fricke (1997) identified the majority of specimens in the T. callionymi type series as E. philippinus , the present study revealed that the paralectotypes of T. callionymi included three specimens (ZMA 112.501, 2 specimens; ZMA 112.503, 1 of 2 specimens) of E. minutus , and four specimens (ZMA 112.502; ZMA 112.503, 1 of 2 specimens; ZMA 112.504; ZMA 112.505) of Enneapterygius unimaculatus Fricke, 1994 . In addition, Enneapterygius waigiensis Herre, 1935 is herein also synonymized with E. tutuilae as the holotype of E. waigiensis (FMNH 17494, 17.2 mm, collected from Waigeo island, Indonesia; Fig. 11B ) possessed the following characters: mandibular pore formula 2 + 2 + 2; orbital tentacle broad and circular; pectoral-fin rays unbranched; first spine of 1st dorsal-fin long, its length 16.7% of SL; and second dorsal fin blackish (based on original description), all characters of E. tutuilae ( Herre, 1935; Fricke, 1997; this study).

Enneapterygius cerasinus and E. fuligicauda are distinguished from E. philippinus by having 12 caudal peduncle scales, and the mandibular pore formula 4 + 1 + 4 (vs. 3 + 2 + 3 in E. philippinus ). In addition, the holotype of E. fuligicauda (ASNP 72062, male, 18.2 mm SL; Fig. 11c ) had the following combination of characters: 12 second dorsal-fin spines; 18 anal-fin rays; 34 and 35 scales in longitudinal series; 17 and 18 pored lateral-line scales; first spine of 1st dorsal-fin relatively short, its length 32.1% of HL; and lower half of head, posterior 1/3 of body, posterior half of anal fin, third dorsal fin and caudal fin uniformly black, all characters consistent with those of Enneapterygius similis Fricke, 1997 , given by Dewa & Motomura (2022). Accordingly, E. fuligicauda should be treated as a valid species and a senior synonym of E. similis . On the other hand, E. cerasinus is herein regarded as a junior synonym of E. unimaculatus , due to the holotype of the former ( Fig. 11d ) sharing the same characters as the latter: 12 second dorsal-fin spines; 9 third dorsal-fin spines; 16 pored lateral-line scales; 18 notched lateral-line scales; body clear reddish-brown marbled with olive (based on original description); orbital tentacle long and broad ( Jordan & Seale, 1906; Fricke, 1994; this study).

Figures

FIGURE 4. Distributional map of five species of Enneapterygius examined in this study.

FIGURE 5. Orbital tentacle shape of A Enneapterygius olivaceus n. sp., KAUM–I. 101347, holotype, male, 19.3 mm SL, Yoron-jima Island, Japan; B E. gracilis, AMS I. 25500-005, male, 19.5 mm SL, Western Australia; C E. nanus, NSMT-P 54443, male, 14.3 mm SL, Eroj Island, Marshall Islands; D E. minutus, lectotype, BMNH 1961.10.20.1, female, 20.4 mm SL, Apia, Western Samoa. Bars represent 1 mm

FIGURE 6. Lengths of A head, B upper jaw, and c 1st spine length of first dorsal-fin (% standard length) relative to standard length in five species of Enneapterygius. Yellow triangles, orange circles, red diamonds, blue squares, and a green star indicate E. gracilis, E. minutus, E. nanus, E. olivaceus n. sp., and E. philippinus, respectively

FIGURE 8. Illustrations of mandibular pore system of Enneapterygius gracilis and Enneapterygius minutus. A double symphyseal mandibular-pores (3 + 2 + 3) (Enneapterygius gracilis, AMS I. 25500-005, male, 19.5 mm SL), B single symphyseal mandibular-pore (mandibular pore formula: 3 + 1 + 3) (Enneapterygius minutus, BMNH 1961.10.20.1, female, 20.4 mm SL) Bars represent 1 mm

FIGURE 9. Photographs of fresh (A, B, D, E) and preserved (C, F) specimens of Enneapterygius minutus. A–C KAUM–I. 62853, male, 19.5 mm SL, Ishigaki-jima Island, Yaeyama Islands, Japan; D–F KAUM–I. 62851, female, 21.4 mm SL, same locality as KAUM–I. 62853

FIGURE 10. Photographs of preserved specimens of Enneapterygius minutus. A BMNH 1961.10.20.1, lectotype of E. minutus, female, 20.4 mm SL, Apia, Western Samoa; B USNM 51800, holotype of Enneapterygius tusitalae, male, 18.5 mm SL, Apia, Upolo Island, Samoa; C USNM 51799, holotype of Enneapterygius pardochir, male, 21.2 mm SL same data as USNM 51800; D FMNH 17388, holotype of Enneapterygius punctulatus, male, 20.8 mm SL, Wala Island, Vanuatu

FIGURE 11. Photographs of type specimens of species currently synonymized with E. philippinus. a ZMA 112.506, lectotype of Tripterygium callionymi, 20.9 mm SL, Sulawesi Island, Indonesia; b FMNH 17494, holotype of Enneapterygius waigiensis, male, 17.2 mm SL, Waigeo Island, Indonesia; c ANSP 72062, holotype of Enneapterygius fuligicauda, male, 18.2 mm SL, Aguni-jima Island, Japan; d USNM 51802, holotype of Enneapterygius cerasinus, female, 19.6 mm SL, Upolu Island, Samoa