Spinose, carnivorous during pre-adult and adult stages. Symbionts are chrysophytes and either aligned along spines or evenly distributed within rhizopodial (pseudopodial) network. Two known formae with slightly different morphology involving more open or closed (evolute or involute) coiling of last whorl. Spines similar in both varieties: round and triangular. Often placed in genus Hastigerina, which however, differs from Globigerinella siphonifera in wall structure, spinosity, cytoplasm, and absence of symbionts (see remarks for Hastigerina).
Ref.: Bé et al. (1973), Deuser et al. (1981), Caron et al. (1987b), Huber et al. (1997).
Distribution: Restricted to temperate to warm water masses, conspicuous member of foraminiferal assemblages in the South Atlantic Central Gyre.
Remark: Globigerinella siphonifera = Globigerinella aequilateralis