Cytaeis tetrastyla Eschscholtz, 1829

Synonyms in the area: Cytaeis atlantica —Mayer 1910; Thiel 1938a; Vannucci 1951a [medusa]. Remarks: species described by Mayer (1910b) under the name Cytaeis atlantica with no specific record for the Atlantic Ocean.

Distribution in South America: medusa—Pacific Ocean, Colombia to Chile, from 7.25°N to 25°S (Fagetti 1973 p. 36; Segura-Puertas 1984; Chirichigno, pers. comm.; IMARPE database of zooplankton); Atlantic Ocean, Brazil to Uruguay, from 4°N to 35°S (Thiel 1938a; Kramp 1957; Vannucci 1957, 1963; Moreira 1973; Navas- Pereira 1974, 1981; Alvariño 1976; Goy 1979; Ramírez & Zamponi 1981; Segura-Puertas 1984; Cely & Chiquillo 1993; Tronolone 2001; Migotto et al. 2002; Baldrich 2007; Silveira & Morandini 2011; Gusmão et al. 2015).

Habitat: medusa—euryhaline and eurythermic species, from 30 to 420m depth (Kramp 1957; Vannucci 1957, 1963, Navas-Pereira 1974). Species recorded in tropical and subtropical regions (Chirichigno, pers. comm.).