The ecological behavior of the radiolarian Cycladophora (?) davisiana (particularly in high latitudes) has produced a large interest among radiolarian specialists. This species has been considered an environmental indicator, as well as a potential inter-hemispheric stratigraphic marker.

The geographic and stratigraphic distribution of C. davisiana Ehrenberg in the Gulf of California is analyzed in the present study. In the southern part of the Gulf, particularly at the water front formed by the encounter of the California Current and the Gulf water itself, its relative abundance in the surface sediments is comparable to that reported in the Sea of Okhotsk. Below the influence of the water front indicated above, C. davisiana has a stratigraphic behavior similar to the one reported in high latitudes.

It was previously hypothesized that the high productivity of C. davisiana in high latitudes is favored by water freezing and subsequent ice melting. The Gulf of California has not experienced ice forming processes; thus in this study it is suggested that the productivity of C. davisiana is favored by the strong mixing created by the formation of some water fronts.

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