A new subtropical species of goby of the genus Luciogobius (Gobiidae) from southwestern Japan Author Koreeda, Reo 0000-0002-6977-3357 The United Graduate School of Agricultural Sciences, Kagoshima University, 1 - 21 - 24 Korimoto, Kagoshima 890 - 0065, Japan k4920583@kadai.jp Author Maeda, Ken 0000-0003-3631-811X Marine Eco-Evo-Devo Unit, Okinawa Institute of Science and Technology Graduate University, 1919 - 1 Tancha, Onna, Okinawa 904 - 0495, Japan Author Motomura, Hiroyuki 0000-0002-7448-2482 The Kagoshima University Museum, 1 - 21 - 30 Korimoto, Kagoshima 890 - 0065, Japan text Zootaxa 2023 2023-11-02 5361 3 390 408 https://www.mapress.com/zt/article/download/zootaxa.5361.3.5/52197 journal article 10.11646/zootaxa.5361.3.5 1175-5326 10144864 AFEFD8C9-ABC1-4793-8B83-49FB7B526389 Luciogobius sp. 7 sensu Shibukawa et al. (2019) [Standard Japanese name: Hauchiwa-yari-mimizuhaze] Figure 10 ; Table 2 Luciogobius sp. 7 : Shibukawa et al , 2019: 67 , figs. 19B, 20E–G, 21C ( Shizuoka Pref. , Japan ). Examined specimens. 10 specimens ( 33.9–65.9 mm SL) from Japan. Shizuoka Prefecture : KAUM –I. 139315, 43.1 mm SL, collected by R . Yamashita. KAUM –I. 157744–157747, 4 specimens , 33.9–65.9 mm SL, collected by H. Saito , 10 June 2021 , KAUM –I. 165340, 49.3 mm SL, KAUM – I. 165341, 41.8 mm SL, collected by K. Mochizuki , 2 Jan. 2022 , Yaizu. Kochi Prefecture : KAUM –I. 159028, 32.1 mm SL, KAUM – I. 159029, 33.2 mm SL, collected by H. Saito , 13 July 2021 , Niyodo River mouth, Haruno. KAUM – I. 159033, 51.3 mm SL, collected by H. Saito , 22 July 2021 , Shinjo River mouth, Suzaki . Morphological characters of examined specimens. Total second dorsal-fin rays 10–12 (modally 12); total anal-fin rays 13–15 (usually 13 or 14); pectoral-fin rays 13–16; vertebrae 17 + 24–25 = 41 or 42; uppermost 2–4 rays free on pectoral fin; fewer than 5 pectoral-fin rays branched (central rays branched in specimens> 50 mm SL); AAA longer than half body depth at anus to anal-fin origin; dorsal-fin origin just above or behind anterior 1/3 of anal-fin base; pectoral-fin membrane strongly concave anteriorly; pelvic fins united. Distribution. Currently known from Japan [ Shizuoka , Wakayama and Kochi prefectures ( Shibukawa et al ., 2019 ; Maeda & Hirashima, 2021 ; Okumura et al ., 2023)]. The species prefers gravel deposits on beaches, rather than rocky coasts ( Shibukawa et al ., 2019 ). Remarks . The pre-dorsal fin length + P 2 A length of 98.4–102.1% of SL in Luciogobius sp. 7 sensu Shibukawa et al. (2019) is similar to that of L. platycephalus , but shorter than in L. griseus n. sp. ( Fig. 7 ). FIGURE 10. Fresh specimens of Luciogobius sp. 7 sensu Shibukawa et al . (2019) from Kochi Prefecture, Shikoku, Japan. A: KAUM–I. 159033, male, 51.3 mm SL; B: KAUM–I. 159029, female, 33.2 mm SL; C: KAUM–I. 159028, female, 32.1 mm SL. Photographs taken immediately after fixation. Three individuals from Kochi Prefecture had relatively shorter pelvic-fin length (3.0–3.2 % of SL vs. 3.1–4.0% of SL) than in Shizuoka specimens ( Fig. 8F ), although specimens from both areas shared fewer than 8 branched pectoral-fin rays, a diagnostic character of the species according to Shibukawa et al . (2019) . The latter reported also that branched rays were absent in individuals <38.0 mm SL. Key to species of the Luciogobius platycephalus complex (except larvae and juveniles): each body proportion needs to be aware of changing with growth (see Figs. 7 , 8 ) 1a. Pectoral fin with 7–13 branched rays (usually more than 10); posterior margin of pectoral-fin membrane not strongly concave (except for free rays).................................................................................. 2 1b. Pectoral fin with 0–8 branched rays (usually 6; 0 in specimens < 38 mm in SL); posterior margin of pectoral-fin membrane strongly concave; occurs in accreting beach......................................................................................... Luciogobius sp. 7 sensu Shibukawa et al . (2019) (Japanese name: Hauchiwa-yari-mimizuhaze) 2a. Pre-dorsal-fin length <70% of SL (except in a specimen 26.1 mm SL); pelvic-fin length> 5.3% of pre-dorsal-fin length in specimens 32 mm SL or larger (> 5.9% in smaller specimens); pre-dorsal-fin length + P 2 A length 95.4–101.6% of SL; bright yellow to green body in live and fresh specimens (except individuals> 50 mm SL); usually occurs along temperate rocky coasts in Japan ( Aomori Pref. to Tanega-shima island) and Korea ….............. Luciogobius platycephalus (Yari-mimizuhaze) 2b. Pre-dorsal-fin length> 69.5% of SL; pelvic-fin length <5.3% of pre-dorsal-fin length in specimens 32 mm SL or larger (<6.0% in smaller specimens); pre-dorsal-fin length + P 2 A length 103.0–107.3% of SL; gray in life (sometimes bluish or purplish), greenish dark brown when fresh; usually occurs near subtropical river mouths or coastal freshwater springs in Japan (Yaku-shima island to Okinawa-jima island)......................... Luciogobius griseus n. sp. (Sumizome-yari-mimizuhaze)