The Centers for Disease Control and Prevention (CDC) places barracuda at the top of its list of predatory fish consumers ought to avoid. This is because large, predatory fish that live near reefs, like barracudas, have a greater chance of passing along ciguatera fish poisoning. As its name implies, the poisoning is caused by a substance called ciguatoxin. Though ciguatera fish poisoning can stir up a highly uncomfortable spectrum of symptoms, it's rarely fatal.
Certain types of algae that breed in deep tropical waters produce ciguatoxin. More specifically, it comes from a one-celled organism called dinoflagellate that breeds on different kinds of algae. Since barracudas are carnivores, they don't consume the ciguatera-tainted algae directly. The small fish that barracuda feed on, such as tuna, herring and anchovies, eat the algae; then, the ciguatera enters the barracuda's system as it digests the fish. While barracudas process the ciguatera, the poison accumulates in their flesh, fat and viscera [source: Hoffman et al].
The ciguatoxin doesn't harm the barracuda, but almost everyone who eats infected barracuda will reap unpleasant consequences. Within 24 hours, the poisoning provokes extreme nausea and vomiting that often lasts for a couple of days. A tingling in nerve endings, or parethesia, may persist longer. Other symptoms include headache and a metallic taste and feeling of loose teeth in the mouth. In atypical cases, ciguatera fish poisoning can produce permanent nerve and cardiovascular damage.
The incidence rate for ciguatera fish poisoning is low, around 5 to 70 cases per 10,000 people every year [source: Louisiana Department of Health and Hospitals]. In once such case in 1997, 17 crew members on a ship off the Texas coastline came down with it after ingesting barracuda [source: CDC].
Other large, predatory fish living in the same area as barracudas can ingest ciguatera. In fact, more than 500 species fit that description, including mackerel, amberjack and grouper [source: Hoffman et al]. To minimize the chances of getting sick when eating predatory tropical fish, consider the part that you're consuming. The toxicity of fish parts, ranked in descending order, goes as follows: liver, intestines, testes, ovaries and flesh [source: Bannerot].
Since there's no way to detect whether barracuda is infected with ciguatera, there's a slight chance that you could get sick from eating it. If you decide to, steer clear of the head and viscera and remember that smaller is better. The larger the barracuda, the more fish it's consumed. If that still sounds risky, just take the safe route and order the fish and chips.