nigricauda, Acanthurus gahm var. Duncker [G.] & Mohr [E.] 1929:75 [Mitteilungen aus dem Zoologischen Staatsinstitut und Zoologischen Museum in Hamburg. v. 44; ref. 15892] Massau Island, St. Matthias Islands, northeast of New Ireland Island, Bismarck Archipelago. Lectotype: ZMH H149 [ex 11759, 1 of 2]. Paralectotypes: ZMH H150 [ex 11759] (1); ZMH 11760 (1) and 11761 (1) ? = ZMH 8229 (1) and 8230 (1). Type catalog: Wilkens & Dohse 1993:407 [ref. 21161] as syntypes. Lectotype selected by Ladiges et al. 1958:166 [ref. 19181] as ZMH 144 [sic 149]. •Synonym of Acanthurus gahhm (Forsskål 1775) -- (Randall 1956:207 [ref. 12221]). •Valid as Acanthurus nigricaudus Duncker & Mohr 1929 -- (Nakabo 2000:1329 [ref. 25182], Allen 2000:123 [ref. 25868], Hutchins 2001:270 [ref. 25841], Kuiter & Debelius 2001:46 [ref. 26232], Nakabo 2002:1329 [ref. 26193], Allen & Adrim 2003:62 [ref. 26830], Matsuura et al. in Kimura & Matsuura 2003:203 [ref. 27510], Motomura et al. 2017:205 [ref. 35490]). •Valid as Acanthurus nigricauda Duncker & Mohr 1929 -- (Randall 1986:814 [ref. 5706], Randall 1988:56 [ref. 14257], Winterbottom et al. 1989:63 [ref. 13251], Randall et al. 1990:423 [ref. 15987], Mohsin & Ambak 1996:555 [ref. 27969], Allen 1997:228 [ref. 23977], Kuiter 1997:366 [ref. 25488], Randall et al. 1997:423 [ref. 25919], Myers 1999:270 [ref. 23965], Fricke 1999:535 [ref. 24106], Allen 2000:93 [ref. 37268], Randall in Randall & Lim 2000:642 [ref. 25122], Laboute & Grandperrin 2000:427 [ref. 25191], Randall et al. 2001:115 [ref. 25316], Hutchins 2001:45 [ref. 25847], Randall 2001:3670 [ref. 26301], Myers & Donaldson 2003:647 [ref. 27495] with first author as Dunker, Lobel & Lobel 2004:76 [ref. 27576] with first author as Dunker, Randall et al. 2004:29 [ref. 27624], Heemstra et al. 2004:3330 [ref. 27945], Randall 2005:579 [ref. 28239], Mundy 2005:488 [ref. 28379], Allen et al. 2006:1736 [ref. 29094], Fricke et al. 2009:107 [ref. 30213], Motomura et al. 2010:226 [ref. 31256], Allen & Erdmann 2012:1023 [ref. 31980], Fricke et al. 2013:271 [ref. 32706], Fricke et al. 2014:182 [ref. 33932], Koeda et al. 2016:101 [ref. 35333], Carpenter et al. 2017:42 [ref. 35143], Fricke et al. 2018:352 [ref. 35805], Dalleau-Coudert et al. 2019:144 [ref. 40104], Fricke et al. 2019:300 [ref. 36673], Zajonz et al. 2019:98 [ref. 36871], Kim et al. 2020:177 [ref. 39118], Psomadakis et al. 2020:559 [ref. 37272], Durville et al. 2021:314 [ref. 38802], Randall 2022:226 [ref. 40150], Noushad K. et al. 2024:46 [ref. 40947]). Current status: Valid as Acanthurus nigricauda Duncker & Mohr 1929. Acanthuridae. Distribution: Indo-West Pacific: KwaZulu-Natal (South Africa), East Africa, Socotra (Yemen), Seychelles, Comoros, Madagascar and Mascarenes (La Réunion, Mauritius, Rodrigues) east to Tuamotu Archipelago (French Polynesia), north to southern Korea and southern Japan, south to Queensland (Australia) and New Caledonia. Habitat: marine.