Caribbean Sharpnose Puffer

The Caribbean sharp-nose puffer is a small fish that is roughly the size of a soft ball at its maximum length of about 4 inches. The color of the puffer is typically white with a darker brown dorsal area. It is adorned with bright blue spots, and its yellow caudal tail fin is bordered by a darker line.

Like most Tetraodontidae, the Caribbean sharp-nose puffer is a slow-swimmer due to its non-streamlined and boxy body shape. To swim, it moves by oscillation of the median fins which propel the fish forward through the water. The pectoral fins serve to lessen the resistance of the water felt by the swimming puffer.

The Caribbean sharp-nose puffer has been observed within a range stretching from South Carolina to the Southern Caribbean. They are typically found at depths above forty meters, however their maximum depth is ninety meters. It is most commonly observed in coral reefs, however they have also been observed in seagrass beds and other shallow marine habitats. Males of the species dominate large territories that contain the smaller territories of one to six females. Males are able to mate with the females within their territory. Smaller males are often wanderers, with no home territory. They are abundant within the Western Atlantic, however they are experiencing a slight decline in population due to coral reef loss.

Few animals are able to overcome the threat posed by the specialized defenses of Caribbean sharp-nose puffer, and thus it is not a common meal for most marine predators. Predation of Canthigaster rostrata is believed to be opportunistic. Nevertheless, species that have been observed to prey on this species of puffer include the great barracuda and the red lionfish. Remains of Caribbean sharp-nose puffer has also been found in stomach contents of the green sea turtle.

Males of the species are extremely territorial. When entering another male's territory, puffer's will flatten themselves and display a mottled coloration as a sign of submission. If a territorial male spots another male within his territory, the defending male will puff up to appear larger, spread his fins, and tilt its body forward. If these warning signs are unsuccessful, the defending male will circle and attempt to bite the other fish. Smaller males of the species often lack a territory, and are known as wanderers.

The Caribbean sharp-nose puffer is oviparous, meaning that the female lays eggs and the embryo develops externally. The typical mating season occurs during the spring, with the majority of spawning occurring at dawn. In order to mate, the male enters the female's territory and performs a display of spreading his fins. If the female is interested in mating, she will display a mottled color pattern, a submissive gesture.

During reproduction the female releases a cluster of eggs onto the sand or into an algae nest, typically in a seagrass bed. This is then fertilized externally by the male puffer. The eggs are transparent and spherical in shape.