Abstract

PROSPECTION OF CIGUATOXINS IN Sphyraena barracuda AND OTHER CARNIVOROUS AND CORALLIVOROUS FISHES OF THE ZONE OF TUXPAN, IN VERACRUZ, MEXICO

Luis Alfredo Barra González, Erick Julián Núñez Vázquez, Rosa Estela Orduña Medrano and Eduardo Alfredo Zarza Meza*

ABSTRACT

Ciguatera is an intoxication brought about by ingestion of fish of tropical and subtropical regions in coastal and insular countries and is associated with reef fishes that feed on algae, coral and other types of organisms in which toxic benthic dinoflagellates of the genus Gambierdiscus live as epibionts, bioaccumulating toxins known as ciguatoxins (CTXs), which are transferred and biotransformed along the trophic chain until reaching the larger carnivorous fishes. Consumption of these fish generates gastrointestinal, neurological and cardiovascular disorders, affecting the public health of the population of these regions. The toxicity of the barracuda (Sphyraena barracuda), and other carnivorous and corallivorous fishes of the families Serranidae, Carangidae, Scoriae, Sphyraenidae, Lutjanidae, Labridae and Scorpaenidae of the zone of Tuxpan, in Veracruz, Mexico, was evaluated in order to determine the presence, concentration and distribution of CTXs. Sixty-four specimens of 11 species of carnivorous and corallivorous fish of the Tuxpan Reef System and petroleum production platforms were captured during the period July to October of 2015. Eighty samples of muscle and liver tissue were obtained for extraction of CTXs and analysis of toxicity using the mouse bioassay (MB) model. The presence of CTX type toxins was detected in the MB, based on the clinical signs presented (diarrhea, disnea, spasms, locomotive problems, lethargy, saltos, ataxia, cyanosis, tremors, salivation, convulsions and respiratory arrest) and time to death. The concentration of toxins was expressed in mouse units (MU). A total of 30% of the samples presented lethal concentrations, while 39% presented sublethal concentrations and 31% of the samples were found to be harmless. The presence of CTX type toxins was confirmed. The most toxic species were the crevalle jack (Caranx hippos/10 MU), followed by the barracuda (Sphyraena barracuda/10 MU), red lionfish (Pterois volitans/10 MU), hogfish (Lachnolaimus maximus/10 MU) and queen parrotfish (Scarus vetula/1.20 MU).

Keywords: Ciguatera, Gambierdiscus toxicus, Tuxpan reef system.