Fig. 2. The kinetics of thiotaurine production in gill homogenates of (A) Calyptogena magnifica and (B) Bathymodiolus thermophilus. Homogenates of C. magnifica and B. thermophilus were exposed, respectively, to 1 mmol l^-1 and 0.25 mmol l^-1 Na₂S at time zero (filled symbols). Controls were obtained by incubating the homogenates with buffer (open symbols). Thiotaurine (triangles) and hypotaurine (circles) concentrations are given as µmol g^-1 dry mass (means ± S.D.; C. magnifica, N=6; B. thermophilus, N=5).