To accommodate its slow locomotion the Caribbean sharp-nose puffer fish has several natural defense mechanisms that protect it from predators. One important defensive adaptation common to most puffer species, including the Caribbean sharp-nose puffer, is its ability to self-inflate. Once thought to result from a puffer holding its breath, an inflated puffer is actually not full of air, but instead water that is gulped into the puffer's expandable stomach when threatened. This highly specialized ability is thanks to the puffer's unique body morphology, including the absence of ribs, which allow the puffer to expand its body size up to three times its normal, deflated size. Unlike most marine
teleosts, the Caribbean sharp-nose puffer does not have scales, but is instead protected by a covering of small spines, known as dermal
spinules, that serve to deter predators and protect the puffer from becoming an easy meal. These spinules are scattered around the puffer's body, but lie most concentrated on the puffer's abdomen. In addition to being a tough meal to swallow, the Caribbean sharp-nose puffer is a potentially lethal choice of prey due to the presence of dangerous toxins:
Tetrodotoxin and
Saxitoxin in the tissues of the puffer. Saxitoxin is a neurotoxin that is one of many
paralytic shellfish poisons that is believed to originate in marine
dinoflagellates. The toxin is known to accumulate in the cells of filter feeders like shrimp, a prey item of the Caribbean sharp-nose puffer, who ingest the toxic bacteria. Saxitoxin will then
bioaccumulate in the tissues of animals further up the food-chain until near toxic levels. This
neurotoxin is believed to cause the death of sea turtles as it has been found in high amounts in the stomach contents of deceased sea turtles who have recently eaten the Caribbean sharp-nose puffer, a host of saxitoxin. == Predation ==