Photonectes achirus Regan & Trewavas, 1930

Villarins, Bárbara T., Dario, Fabio Di, Eduardo, Leandro N., Lucena-Frédou, Flávia, Bertrand, Arnaud, Prokofiev, Artem M. & Mincarone, Michael M., 2022, Deep-sea dragonfishes (Teleostei: Stomiiformes) collected from off northeastern Brazil, with a review of the species reported from the Brazilian Exclusive Economic Zone, Neotropical Ichthyology (e 220004) 20 (2), pp. 1-78 : 58-59

Photonectes achirus Regan & Trewavas, 1930

( Fig. 18A )

Diagnosis. Photonectes achirus differs from congeners by the absence of the pectoral fin; IV 31–36; one pair of luminous organs inside mouth; chin barbel length 70–80% HL, with a small terminal bulb and a terminal appendage with a secondary, small, bulb at its tip; presence of blue luminous tissue in a midventral band extending from the pectoral region to the pelvic fin, with short transverse streaks alternating with serial photophores, and in patches under OV-1 and OV-2 photophores, on sides of isthmus, under the lower jaw, above the posterior end of the maxilla, between the eyes, and above the occipito-vertical articulation; BR 6–8 (Morrow, Gibbs, 1964; Flynn, Klepadlo, 2012; Prokofiev, Klepadlo, 2019; Prokofiev, Frable, 2021).

Geographical distribution. Known from a few records in the western and central Pacific and western North Atlantic oceans, off United States and in the Caribbean Sea (McEachran, Fechhelm, 1998; Harold, 2003; Mundy, 2005; Klepadlo, 2011; Flynn, Klepadlo, 2012). Photonectes achirus is reported for the first time in the South Atlantic based on three specimens collected off Rio Grande do Norte (including the seamounts) and Paraíba States in the Brazilian EEZ, between depths of 70 and 800 m ( Fig. 14F ) .

Remarks. Two specimens listed as Photonectes sp. (NPM 6867, 26–29 mm; AB2#42A) in the Supplementary Material S1 likely represent P. achirus , but their identification could not be confirmed at species level due to their extremely small sizes.

Specimens examined. 3 (33–79 mm SL): NPM 4629, 1 (79 mm), AB2#54B; NPM 4695, 1

(33 mm), AB2#21; NPM 4924, 1 (damaged), AB2#28.

Figures

FIGURE 14 | Records of species of the Melanostomiinae (A–F) collected during the ABRACOS expeditions off northeastern Brazil. Oceanic islands: RA, Rocas Atoll; FN, Fernando de Noronha Archipelago.

FIGURE 18 | A. Photonectes achirus, NPM 4629, 79 mm SL; B. Thysanactis dentex, NPM 4639, 138 mm SL. Scale bars = 10 mm.