The sharp-nose puffer fish is a relatively small football-shaped fish that has a large pointed snout, small fins toward the posterior end of the body, and a prominent tail. The sides of the fish vary in color from a pale yellow to white with bright blue spots. They can be found throughout the shallow waters of the Caribbean. The edges of the tail-fin have thick dark borders that distinguish the Caribbean sharp-nosed puffer from other similar species. In females their dorsal side is usually brown and in males it is usually grey.
The sharp-nose puffers are territorial and coexist with other sharp-nose puffers in a very complex social structure. The females will defend a small, permanent territory, and the males defend a larger territory that encompasses several of the smaller female territories. The puffers know their territory boundaries of their other neighbors. If one puffer must cross into another puffer’s territory they change to a mottled color pattern that is thought to help camouflage them from the territories owner. This color also indicates that they are no threat if they are sighted. If the puffer is caught going into another puffer’s territory it is met with aggressive displays, such as tilting the body and presenting flank. If this display does not deter the intruder the defending puffer will face its enemy head on with fins spread out to make it look bigger. If the intruder yields to the defending puffer it will display a submissive look where he belly is flattened and it will swim away. However, if the intruder persists the two fish will circle each other in an attempt to bite one another.
The sharp-nose puffer’s main defense against predators is to retreat into a reef recess. However, as a last resort puffers can inflate themselves to make them more difficult swallow. Furthermore, because they are poisonous, only on rare occasions do predators such as eels, groupers, snappers, and barracudas attempt to eat it.
Sharp-nose puffers are omnivorous fish that search the reef for food very actively. They usually eat small crabs, shrimps, and worms. They have also been seen picking at invertebrates, algae, and sea grasses. They are, however, not considered dangerous to scuba divers & snorkelers. They will often come close if divers or snorkelers move slowly and regulate their breathing. Similar to other puffer fish, sharp-nose puffers have been known to live up to 10 years.