
Fig. 4. Rates of oxygen consumption (grey columns) and sulfide oxidation (black columns) in mussel gills exposed to the low and high concentration of 5-HT. Numbers over each pair of columns refer to the oxygen/sulfide ratio for that measurement pair. Values are means ± S.D. (N=34). Asterisks designate significant difference between low- and high-5-HT treatments; double daggers designate significant difference between mussel species (Bonferroni test). (A) Geukensia demissa gills. (B) Mytilus edulis gills.