Pempheris schwenkii Bleeker, 1855

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 schwenkii Bleeker, 1855

Figs 12 , 13 , Suppl. material 2 Standard Japanese name: Minami-hatampo

Pempheris schwenkii Bleeker, 1855: 314 (type locality: Batu Islands, Sumatera Utara Province, Indonesia); Hatooka 1997 (in part): 380, unnumbered fig. (p. 381, lower middle fig.); Randall and Lim 2000: 622; Hatooka 2002 (in part): 878; Yoshigou and Nakamura 2002: 107; Yoshigou and Nakamura 2003: 49; Yoshigou 2004: 19; Chen 2003: 134, unnumbered fig.; Senou et al. 2006 a: 77; Senou et al. 2007: 56; Shao et al. 2008: 254; Yoshino 2008 (in part): 211; Ito 2009: 80, unnumbered fig.; Chen et al. 2010: 265, fig. C, E; Koeda et al. 2010 a: 75; Koeda et al. 2010 b: 81; Motomura et al. 2010: 131, fig. 252; Shen and Wu 2011: 498, unnumbered fig.; Koeda et al. 2012 a: 71; Koeda et al. 2012 b: 1086; Miura 2012: 59 (without scientific name; shown as “ Minami-hatampo ”); Chiang et al. 2014: 183, unnumbered fig.; Hatooka and Yagishita 2013 (in part): 984; Koeda et al. 2013 a: 235; Koeda et al. 2013 b: 222, fig. 1; Koeda et al. 2013 c: 126; Motomura et al. 2013 (in part): 168; Shao et al. 2013 (in part): 163, unnumbered fig. (lower); Koeda et al. 2014: 314; Koeda and Motomura 2015: 139; Motomura and Matsuura 2014: 271, unnumbered figs; Koeda et al. 2015: 275; Koeda et al. 2016 a: 519; Koeda et al. 2016 c: 8, fig. 3 H; Koeda and Motomura 2017 a; Koeda and Motomura 2017 b: 266, fig. 3 D, E; Kimura et al. 2017 (in part): 120, fig. 1; Planning and Tourism Division of Kikai Town 2017: 4, unnumbered figs; Nakae et al. 2018: 266; Koeda 2018 b: 298, unnumbered fig. (lower right fig.); Koeda 2018 b: 194, unnumbered figs; Mochida and Motomura 2018: 30; Koeda 2019: 929, unnumbered figs; Fujiwara and Motomura 2020: 28; Koeda 2020 b: 929, unnumbered figs; Motomura and Uehara 2020: 45; Koeda et al. 2022: 10; Motomura 2023: 129 (in part).

Pempheris adusta (not Bleeker, 1877): Shimose 2021: 122, fig. B.

Pempheris japonicus (not Döderlein, 1883): Snyder 1912: 497.

Pempheris oualensis (not Cuvier, 1831): Chen 2003: 134, unnumbered fig.; Shao and Chen 2003: 255, unnumbered figs; Yang et al. 2013: 167, unnumbered fig.

Liopempheris vanicolensis (not Cuvier, 1831): Jordan and Hubbs 1925: 229.

Pempheris vanicolensis (not Cuvier, 1831): Okada 1938: 179; Okada and Matsubara 1938: 179 (in part); Matsubara 1955: 590 (in part); Aoyagi 1948: 49; The Marine Ecological Researching Society of Kagoshima University 1966: 19; The Marine Ecological Researching Society of Kagoshima University 1967: 32; Takahashi 1970: 58; Chen et al. 2010: 266, fig. A; Chang et al 2011: 46.

Pempheris xanthoptera Tominaga, 1963 (in part paratypes): 287; Masuda et al 1975 (in part): 199, pl. 33 - C; Yoshino et al. 1975: 75; Hayashi 1984 (in part): 160.

Pempheris sp.: Uchida 1933: 218 (in part).

Diagnosis.

Counts of holotype and paratypes are given in Table 2 . Dorsal-fin rays VI – VII, very rarely VII, 9–10, very rarely 10; anal-fin rays III, 35–42, usually> 37; pectoral-fin rays 16–18; pored lateral-line scales 44–53; scale rows above lateral line 3 ½ or 4 ½, very rarely 4 ½; scale rows below lateral line 10–13; predorsal scales 23–30; circumpeduncular scales 10–12; gill rakers 6–9 + 18 – 22 = 25–30; head length 27.9–33.0 %; body depth 40.2–47.2 %; eye diameter 35.5–45.5 %; upper jaw length 50.0–56.7 %; maximum 126 mm SL; scales weakly ctenoid, deciduous, thin, semicircular in shape, far wider than long (see Koeda et al. 2013 a: fig. 2 a); body golden in day time and silverish in night time; tip of dorsal fin and / or anterior margin of dorsal fin blackish; faint blackish band on anal-fin outer margin; blackish band on anal-fin base; posterior margin of caudal fin dusky; no blackish blotch on pectoral-fin base; posterior nostril usually slit-like; narrow band of villiform teeth in jaws; abdomen cross-sectional outline V-shaped.

Distribution.

Widely distributed in the western Pacific Ocean. In Japanese waters, this species is known from Tanega-shima to Yonaguni-jima islands in the Ryukyu Archipelago, Minamidaito-jima Island in Daito Islands, and very rarely collected from Minamisatsuma in Kagoshima Prefecture. In Taiwanese waters, this species is known from Daxi in Yilan County, Gungliau and Yeh Liu in New Taipei City, Chi-gu in Tainan County, Ke-tzu-liao in Kaohsiung County, Hengchung, and Dong-gang, Kenting in Pingtung County, Fugang in Taitung County, Lanyu, and Penghu (Fig. 13 ). Specimens are collected from the caves or crevasses in coral reef areas of 0–25 m depth.

Remarks.

Pempheris schwenkii has been thought to be widely distributed in the Indo-Pacific Ocean. However, our genetic study revealed the interspecific difference between specimens from the Indian and Pacific oceans, and southern Japan. Bleeker (1855) described P. schwenkii based on type specimens collected from Batu Island of western Indonesia, eastern Indian Ocean. Although a significant genetic difference is observed among the specimens from these three localities, the morphologies of the species are very similar. Furthermore, the morphological characters were difficult to determine from the dehydrated condition of the syntypes of P. schwenkii ( RMNH. PISC. 6160). The species composition of genus Pempheris around this area was closer to that of the western Pacific than that of the Indian Ocean. Therefore, P. schwenkii was determined as the name of the Pacific Ocean species ( Koeda et al. 2014) and the Indian Ocean species described as a new species, P. tominagai Koeda, Yoshino & Tachihara, 2014 . In the present study, a single specimen collected from the Andaman Sea was discovered, and is identified as P. schwenkii based on the pink caudal fin (vs yellow in P. tominagai ). This fact supports the conclusion of Koeda et al. (2014) that P. schwenkii may be widely distributed from the Pacific to the Andaman Sea including the type locality (Batu Islands, Sumatera Utara Province, Indonesia) of the species.

Similarly, the Pacific species and the southern Japanese species also showed significant difference between specimens from south of the Ryukyu Archipelago and specimens from mainland Japan (unpublished data). These two are clearly different species, because both species are distributed in the Osumi Islands (Tanega-shima, Yaku-shima, and Kuchinoerabu-jima islands; Fig. 13 ), but the genetic mixability did not appear in the genetic structure analysis (unpublished data); the genetic identification and the diagnostic caudal-fin colorations (pink to brown in P. schwenkii vs yellow in P. xanthoptera ) were well matched (Fig. 3 ).

On the basis of the taxonomic confusion between P. schwenkii and P. xanthoptera , the standard Japanese name “ Minami-hatampo ” was used for both species, and recently, P. schwenkii was tentatively recognized as having “ Pacific ” and “ southern Japan ” types, the latter closely matching P. xanthoptera sensu Tominaga (1963) (e. g., Koeda 2017 b, 2018 a, b, 2020 a; Kimura et al. 2017); see remarks of P. xanthoptera ]. The Japanese name “ Minami-hatampo ” was first given by Okada (1938) for P. vanicolensis in his list. His identification may follow Jordan and Hubbs (1925) which indicated that Snyder (1912) ’ s P. japonica from Okinawa-jima Island was a misidentification of P. vanicolensis . However, P. vanicolensis is very rare in Japanese waters, and has never been collected from Okinawa-jima Island ( Nakamura et al. 2022). In addition, the re-examination of the Snyder’s specimen of P. japonica ( CAS-SU 22002) revealed that it was in fact a misidentification of P. schwenkii , which is the most common species around Okinawa Island. Although Okada (1938) included Kyushu in the distribution of “ Minami-hatampo ” which is the range of P. xanthoptera , the situations mentioned above suggest that his species should be P. schwenkii . These facts indicate that the standard Japanese name “ Minami-hatampo ” should be adopted for the species P. schwenkii .

The juveniles of P. schwenkii were collected from Minami-daito Island in the Daito Islands. Pempheris ufuagari is known as an endemic species which is found in the Daito and Ogasawara islands (see below), meaning that interaction between the species can occur at these localities. However, P. schwenkii and P. xanthoptera have never been collected from the Ogasawara and Daito islands, respectively, indicating that the P. ufuagari and P. schwenkii group (with P. xanthoptera ) may have a different dispersal strategy.

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 12. Fresh specimen of Pempheris schwenkii, NMMB-P 27013, 100.3 mm SL, Hengchung, Pingtung, Taiwan.

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.