ORIGIN OF COILING DIFFERENCES IN LIVING NEOGLOBOQUADRINIDS IN THE WALVIS BAY-REGION, OFF NAMIBIA, SOUTHWEST AFRICA

Seasonal and spatial differences in coiling in Recent neogloboquadrini ds seem to be controlled mainly by differences in food requirements an d associated timing of reproduction between the left- and right-coiled types. The observation that the change in coiling from dominantly lef t to right takes place at surface water temperatures ranging from 7-9- degrees-C in high Northern Hemisphere latitudes to 14.5-degrees-C in t he Walvis Bay region suggests that the significance of temperature in coiling in neogloboquadrinids is overestimated in the literature.