Reciprocal effects of caulerpenyne and intense herbivorism on the antioxidant response of Bittium reticulatum and Caulerpa taxifolia.

We studied the antioxidant enzyme response of the gastropoda Bittium reticulatum feeding the toxic alga Caulerpa taxifolia, and also the effects of intense herbivorism on caulerpenyne production and on the antioxidant response of C. taxifolia. B. reticulatum were maintained in two separated aquariums containing Posidonia oceanica or C. taxifolia. Glutathione peroxidase, glutathione reductase and glutathione S-transferase activities were significantly higher in B. reticulatum living in presence of C. taxifolia with respect to animals living in P. oceanica aquarium. Malondialdehyde levels in B. reticulatum showed similar values in both environments. Caulerpenyne levels were significantly higher in C. taxifolia fronds after herbivore exposure. C. taxifolia activities of catalase and glutathione reductase significantly increased in presence of B. reticulatum. B. reticulatum exposed to caulerpenyne evidenced antioxidant enzyme adaptations to prevent oxidative damage. The presence of B. reticulatum in the aquarium induces a protective adaptation in C. taxifolia in order to reduce the herbivorism.