Thysanactis 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 : 59

Thysanactis Regan & Trewavas, 1930

Diagnosis. Thysanactis can be distinguished in the Melanostomiinae by the dorsal and anal fins placed posteriorly on body, anal-fin origin slightly anterior to dorsal-fin origin; first pectoral-fin ray long and isolated, ending in 5–6 filaments, followed by 10–11 additional pectoral-fin rays; chin barbel short, similar in length to head length, ending in a round terminal bulb covered with filaments; IP 20; PV 31–32; VAV 14–16; OV 30–32; VAL 14–16; AC 11–12 (Morrow, Gibbs, 1964; Sutton et al., 2020). A single valid species (Fricke et al., 2022).