Q10 values were different among the three species (Table 2): Q10s between 2 and 14 -C were greater than 1 and it was largely higher in N. virei than in the other two species. In contrast, Q10 values between 21 and 28 -C were smaller than 1 in all three species. G. fossarum and N. rhenorhodanensis had similar Q10 values, that are apparently twice higher of N. virei.