Melanocetus johnsonii Günther, 1864
(Figs. 1C, 3)
Diagnosis. Metamorphosed females of Melanocetus johnsonii differ from congeners by the nearly straight anterior margin of the vomer; least outside width between frontals 13.5–28.6% SL; 48–134 teeth on upper jaw, 32–78 on lower jaw; length of longest tooth in lower jaw 8.4–25.0% SL; width of pectoral-fin lobe 10.7–17.8% SL; width of escal bulb 4.3–8.6% SL; length of illicium 32.4–60.8% SL; esca with posterior and usually anterior crests; skin with minute spinules over most of body; integument relatively thick (1.55 mm) (Pietsch, Van Duzer, 1980; Pietsch, 2009).
Geographical distribution. Melanocetus johnsonii occurs in the Atlantic, Pacific and Indian Oceans. It was previously reported in Brazilian waters based on specimens collected off Saint Peter and Saint Paul Archipelago (MCZ 42849, 0º24’N 27º32’W; Pietsch, Van Duzer, 1980), Espírito Santo State (MNRJ 30702, 20º27’40”S 39º38’06”W; MNRJ 30703, 19º43’40”S 38º39’50”W; Pietsch, 2009), and Trindade Island (ISH 2352–1968, 21º04’S 30º08’W; Pietsch, Van Duzer, 1980; Menezes et al., 2003; Pietsch, 2009). The five specimens identified here were collected off Fernando de Noronha Archipelago and seamounts off Rio Grande do Norte State, between depths of 58 and 1,113 m (Fig. 3).
Remarks. Six additional juvenile (20–88 mm SL) specimens of Melanocetus collected in this study were only identified to genus (NPM 4956, NPM 4957, NPM 4967, NPM 4971, NPM 4976, NPM 4983). They were collected off Pernambuco State, Fernando de Noronha Archipelago, and near the seamounts off Rio Grande do Norte State, between depths of 680 and 1,113 m. Melanocetus murrayi Günther, 1887, with a circumglobal distribution, was recorded off Brazil, around Saint Peter and Saint Paul Archipelago (MCZ 42847, 1º20’30”S 27º37’30”W) and off northern Trindade Island (ISH 1180– 1968, 17°33’S 28°13’W) (Pietsch, Van Duzer 1980; Menezes et al., 2003; Pietsch, 2009; Melo et al., 2020; Fig. 3).
Material examined. NPM 3837, 1, 10.5 mm, RV Antea, sta. AB1/7, 3°57’36.1”S 32°31’56.7”W to 3°56’48.1”S 32°31’05.3”W, 58 m, 3 Oct 2015, 19:22–19:52 h; NPM 3838, 1, 13.5 mm, RV Antea, sta. AB1/9, 3°28’15.4”S 32°45’31.5”W to 3°27’36.5”S 32°46’43.9”W, 105 m, 4 Oct 2015, 21:17–21:47 h; NPM 4970, 2, 14–19 mm (Fig. 1C), RV Antea, sta. AB2/52A, 3°43’16.2”S 33°25’09.8”W to 3°42’14.2”S 33°24’36.2”W, 822–984 m, 2 May 2017, 11:47–12:18 h; NPM 4981, 1, 17.5 mm, RV Antea, sta. AB2/59A, 3°38’01.6”S 36°31’46.3”W to 3°38’36.1”S 36°17’49.7”W, 700–1113 m, 5 May 2017, 21:57–22:37 h.