Growth rates of six coccolithophorid strains as a function of temperature

Abstract

We determined growth rates of six coccolithophorid strains (five species) as a function of temperature. We grew four strains (three species: Emiliania huxleyi , Gephyrocapsa oceanica , and two strains of Calcidiscus leptoporus ) at six temperatures between 6°C and 25°C, Coccolithus braarudii at four temperatures, and Syracosphaera pulchr a at two temperatures. The growth rates were to a large extent consistent with the biogeographical distributions of these species. C. braarudi i grows relatively fast at low temperatures, the two strains of C. leptoporus have temperature optima of 12°C and 20°C, E. huxleyi has an optimum at 20°C, and the growth rate of G. oceanica (and S. pulchra ) increases up to the highest tested temperature of 25°C. This shows that maximum growth rate is an important factor in controlling distribution in the ocean, but it is not the only one.