The influence of temperature on the growth and fatty-acid composition of the microalga Ske[etonema costatum (CCAP 1077/b) has been studied. The maximum specific rates of growth (mu(m)) and productivity (P-B) were reached between 293 and 298 K. The experimental values of mu(m)-T were adjusted to the function : mu = mu(0)’.T.exp(-E(a)/RT)-mu(d).exp(-E(d)/RT). The total content of the saturated acids reached a minimum at 293 K, whereas the maximum amounts of polyunsaturated acids and Sigma n-3 HUFA (highly unsaturated n-3 fatty acids) occurred at 293 and 295.5 K, respectively.