Eucheilota duodecimalis A. Agassiz, 1862

Distribution in South America: medusa—Atlantic Ocean, Brazil to Uruguay, from 20.5°S to 35°S (Vannucci 1960, 1963; Moreira 1973, 1978; Navas-Pereira 1974, 1980, 1981; Ramírez & Zamponi 1981; Correia 1983; Tronolone 2001, 2008; Migotto et al. 2002; Silveira & Morandini 2011; Nogueira Jr. 2012; Bonecker et al. 2014; Nagata et al. 2014a, 2014b; Nogueira Jr. et al. 2015a).

Habitat: medusa—meroplanktonic, eurythermic and euryhaline species, from 19 to 30m depth (Vannucci 1963; Correia 1983).