AB 9:221-225 (2010)  -  DOI: https://doi.org/10.3354/ab00255

ABSTRACT: Domoic acid (DA), a neurotoxin produced by the diatom genus Pseudo-nitzschia, has been recently found to accumulate in Octopus vulgaris. To elucidate inter-animal variation in DA concentration in octopus digestive glands and its relation to biometric (size and body mass) and biological (sex and maturity) parameters, 54 specimens were caught in the same fishing area during a bloom of toxic plankton. Toxin concentration in female octopuses, as determined by liquid chromatography, was significantly inversely correlated with octopus mantle length (r² = 0.63), body mass (r² = 0.62) and weight of the digestive gland (r² = 0.55). A tendency for decreasing DA concentration with maturity stages was also observed in females. No significant correlation was observed between DA concentration and any biometric or biological parameter of male specimens. Negative correlations during periods of toxin uptake suggest that younger female octopuses are greater consumers of toxic prey and represent a higher threat as DA vectors in the marine food web.

KEY WORDS: Amnesic shellfish poisoning · Cephalopods · Sex · Size · Food web