This species (Fig. 14) has very broad tolerances for all physical parameters analysed in this paper. It occurs in a wide geographic range from mid to low latitudes (subtropical-tropical) but rarely exceeds 5% relative abundance. Globigerinoides conglobatus occurs only where sea surface temperatures are above about 20 ūC in summer. Hemleben et al. (1989) suggest that G. conglobatus is a surface dweller but may descend to deeper depths because it is the only globigerinoid species with a calcite crust. If this is true the species does not prefer a distinct vertical water structure or stratification during its vertical migration, which is unusual in comparison with deep-dwelling planktic foraminifera (e.g. G. hirsuta, G. truncatulinoides). Its depth habitat may be restricted to the depth of the pycnocline.