Saxitoxin monitoring in three species of Florida puffer fish

Beginning in April 2002, three species of Florida puffer fish from around the state of Florida, USA were monitored for the presence of saxitoxin (STX). In total, 873 southern (Sphoeroides nephelus), 171 checkered (S. testudineus), and 53 bandtail (S. spengleri) puffer fish were collected between 2002 and 2006 from eight regions: Jacksonville, the Indian River Lagoon, Tequesta, the Florida Keys, Charlotte Harbor, Tampa Bay, Cedar Key, and Apalachicola. Emphasis was placed on collecting specimens from the Indian River Lagoon (IRL), where recreational harvesting of puffer fish led to 28 cases of saxitoxin puffer fish poisoning (SPFP) between January 2002 and May 2004. Southern puffer fish from the northern IRL routinely contained the highest concentrations of STX, with average levels in the skin of 1787μg STXequiv./100g tissue. Elevated concentrations were also found in the muscle (1102μg STXequiv./100g), gut contents (539μg STXequiv./100g), gonads (654μg STXequiv./100g), and liver (214μg STXequiv./100g). Lower, yet significant (above the action limit of 80μg STXequiv./100g tissue), concentrations of STX were also detected in the skin (599μg STXequiv./100g), muscle (233μg STXequiv./100g), gut contents (197μg STXequiv./100g), and gonads (239μg STXequiv./100g) of southern puffer fish from Tequesta in the southern IRL, as well as in the gonads (122μg STXequiv./100g) of Jacksonville southern puffer fish and the skin (265μg STXequiv./100g) of Tampa Bay southern puffer fish. STX concentrations above the action limit were also found in the skin of bandtail puffer fish from the IRL (620μg STXequiv./100g), Tequesta (374μg STXequiv./100g), and the Florida Keys (230μg STXequiv./100g). Checkered puffer fish collected from the IRL, Tequesta, and the Florida Keys on average were nontoxic, containing STX levels below the action limit in all tissues.