This species (Fig. 7) does not exceed 1.5 % relative abundance and contributes less than 1 psu in most assemblages where it occurs. It has a preference for warm sea surface temperatures with higher temperatures in summer and tolerates a wide
range of seasonal sea surface temperature variation. The occurrence is restricted to areas with elevated salinities between about 35.5 psu (mostly 36 psu) to 37 psu and low seasonality in salinity. The preference for areas with low to
intermediate vertical temperature gradients and stratification reflects its preferred habitat in warm subtropical environments with high temperatures at 200 m. D. anfracta occurs in the central North Atlantic gyre. In the Indian Ocean it was
observed in only one sample. The underlying cause of this biogeographic limitation may be the preference for elevated salinities which do not exceed 36 psu in data from the southern hemisphere.