Pempheris xanthoptera Tominaga, 1963

Koeda, Keita & Bessho-Uehara, Manabu, 2024, A review of the genus Pempheris (Teleostei, Pempheridae) found in Japan and Taiwan, ZooKeys 1220, pp. 123-163 : 123-163

Pempheris xanthoptera Tominaga, 1963

Figs 13 , 17 , Suppl. material 2 New standard Japanese name: Mizuho-hatampo

Pempheris xanthoptera Tominaga, 1963: 286, fig. 12 (type locality: Manazuri, Kanagawa Prefecture, Japan); Hiyama and Yasuda 1971: 204, fig. 440; Masuda et al. 1975: 199, pl. 33 - C; Hayashi 1984: 160, pl. 151 - D; Kohno 1986: 135, fig. 1; Randall et al. 1997: 35; Koeda et al. 2022: 11.

Pempheris molucca (not Cuvier, 1829): Temminck and Schlegel 1844: 85, pl. 44, fig. 3.

Pempheris oualensis (not Cuvier, 1831): Mochizuki 1995: 389, unnumbered fig. (in part).

Pempheris schwenkii (not Bleeker, 1855): Masuda and Kobayashi 1994: 180, fig. 6; Mochizuki 1995: 389, unnumbered fig.; Hatooka 1997 (in part): 380, unnumbered fig. (p. 381, lower left fig.); Hatooka 2002 (in part): 878; Takayama et al. 2003: 1317, fig. 2; Senou et al. 2006 b: 463; Aramata 2007: 172, unnumbered figs; Yoshino 2008 (in part): 211; Takagi et al. 2010: 69, unnumbered figs; Kohno et al. 2011: 208, unnumbered fig.; Senou et al. 2012: 212; Hatooka and Yagishita 2013 (in part): 984; Koeda et al. 2013 a: 237; Motomura et al. 2013 (in part): 168, unnumbered fig.; Kawano et al. 2014: 48; Koeda et al. 2014: 327; Ikeda and Nakabo 2015: 160, figs 1–3; Takeuchi et al. 2015: 8; Iwatsubo et al. 2016: 22, unnumbered figs; Kaburagi 2016: 98, lower fig. (without scientific name; indicated as “ Minami-hatampo ”); Kimura et al. 2017 (in part): 120, fig. 2; Koeda 2017 a: 9, fig. 2 (middle); Koeda 2017 b: 190, unnumbered fig.; Koeda and Motomura 2017 a; Kagoshima City Aquarium Foundation 2018: 210, unnumbered fig.; Koeda 2018 b: 298, unnumbered fig. (lower left fig.); Koeda 2018 c: 343, unnumbered figs; Murase et al. 2019: 132, fig. 284; Koeda 2020 a: 407, unnumbered figs; Murase et al. 2021: 166, fig. 340; Koeda 2022: 158, unnumbered fig.; Motomura 2023: 129 (in part).

Pempheris vanicolensis (not Cuvier, 1831): Okada 1938: 179 (in part); Okada and Matsubara 1938: 179 (in part); Matsubara 1955: 590 (in part); Abekawa and Nishi 1969: 24.

Pempheris japonica (not Döderlein, 1883): Nakamura 1993: 148, fig. 6.

Diagnosis.

Counts of of holotype and paratypes are given in Table 2 . Dorsal-fin rays VI – VII, 9; anal-fin rays III, 35–42; pectoral-fin rays 16–19; pored lateral-line scales 45–54; scale rows above lateral line 3 1 / 2; scale rows below lateral line 10–13; predorsal scales 23–28; circumpeduncular scales 12–14; gill rakers 7–9 + 18 – 21 = 25–27; head length 27.9–31.9 %; body depth 39.3–45.4 %; eye diameter 36.4–44.1 %; upper jaw length 48.3–57.1 %; maximum 137 mm SL; scales weakly ctenoid, very deciduous, thin, semicircular in shape, far wider than long (see Koeda et al. 2013 a: fig. 2 a); body golden in daytime, but silver in night time; no blackish blotch on; tip of dorsal fin distinctly blackish; anal-fin base zonal blackish, and margin very faintly blackish; caudal fin yellow (disappears in fixed specimens); pectoral and pelvic fin hyaline or pink; posterior margin of caudal fin dusky; body light brown to dark brown in fixed specimen; black pigmentation on each fins usually persistent; no blackish blotch on pectoral-fin base; posterior nostril usually open, not compressed; narrow band of villiform teeth in jaws; abdomen cross-sectional outline V-shaped.

Distribution.

Endemic to the Northwest Pacific, recorded only from Japan, Jeju Island in Korea ( Kim and Sakai 2004), and China. In Japanese waters, this species is known from Pacific coast (north to Boso Peninsula in Chiba Prefecture, south to Kagoshima Prefecture), Tsushima Island, East China Sea coast (north to Goto Islands in Nagasaki Prefecture, south to Kagoshima Prefecture), Izu-oshima, Miyake-jima and Hachijo-jima islands in Izu Islands, Chichi-jima, Haha-jima, Ototo-jima islands in Ogasawara Islands, Tanega-shima, Yaku-shima, Kuchinoerabu-jima, Iou-jima and Take-shima islands in northern Ryukyu Archipelago (Fig. 13 ).

Remarks.

Although Tominaga (1963) described P. xanthoptera based on its differences in fin color and distributional pattern from P. schwenkii , the former has been usually considered as a junior synonym of the latter in recent publications in Japan (see the synonym list) without any discussion. Our genetic analysis revealed apparent differences between these two species with high node support values (Fig. 3 ). The morphological comparison showed the additional small difference between these two species, such as P. xanthoptera has the posterior nostril usually open, not compressed (vs slit-like; see Koeda et al. 2014: fig. 8), and caudal fin yellow (vs pink to brown). The validity of P. xanthoptera was discussed in the remarks of P. schwenkii .

The standard Japanese name “ Minami-hatampo ” was used for both species and caused confusion, but this name should be adopted for P. schwenkii (see remarks of P. schwenkii ). Therefore, a new standard Japanese “ Mizuho-hatampo ” is proposed for P. xanthoptera . “ Mizuho ” is an alternative name for Japan that frequently appears in ancient Japanese mythology and poetry, and it derives from the fact that the species is primarily distributed across the Japanese mainland.

Figures

Figure 3. The Maximum-Likelihood (ML) tree of Pempheris species recovered from mitochondria 16 S and COI. Values of the Shimodaira – Hasegawa-like approximate likelihood ratio test (SH-aLRT) for the ML tree, bootstrap values (BS) of the NJ tree, and the posterior probability (PP) for the BI tree are indicated at the nodes unless the branch lengths are < 0.01. The museum voucher number of specimens are listed next to the taxon name.

Figure 13. Distribution of Pempheris schwenkii (diamonds) and P. xanthoptera (solid triangles and star for type locality) based on the collection locality of the specimens. Open triangles for literature records of P. xanthoptera.

Figure 17. Fresh specimen of Pempheris xanthoptera, KBF-I 00268, 123.0 mm SL, Amaji, Otsuki, Kochi.