Biotransfer/accumulation of toxins produced by dinoflagellate Prorocentrum concavum to domino damsel (Dascyllus trimaculatus) fish

Abstract

Toxic dinoflagellate Prorocentrum concavum cells (DC) implicated in ciguatera poisoning were lyophilized and mixed with a standard fish food and fed to Domino damsel fish (Dascyllus trimaculatus). Damsel fish fed 50/50-SC/DC and 100% DC diets exhibited physical and behavioral changes as well as death. Feed refusal was apparent among the fish fed 100% DC diet. Toxicity of the control group could be attributed to previous exposure of the fish to other polyether compounds in its natural habitat or even other chemicals. Fish extracts of both control and treatment groups were toxic when tested on the Stick-enzyme immunoassay for ciguatoxin. Okadaic acid was detected in P. concavum, but no okadaic acid was found in any of the fish tissue extracts. Further studies are needed to determine the transfer of toxin to the fish through diet before any conclusion is made.