Friday, January 15, 2010

What are porcupine fish?

The body of the porcupine fish is round; much like that of the puffers, but how they inflate the body is distinctly different.

Named for its spine-covered skin, the porcupine fish can be found in oceans throughout the world. This interesting little fish is a member of the Diodontidae family and is most often found swimming among or near coral reef areas. The porcupine fish range in size from around three inches with some of the larger species reaching up to nineteen inches or more. In the larger of these fish the spines are set into the skin, much like the puffers, erecting only when the fish is threatened and has inflated its body. But the smaller of the species have spines that are permanently erected whether the fish is aggravated or not. With around fifteen species of this fish, some are very popular as aquarium specimens while others are blown up, dried and sold as souvenirs. Most species of porcupine fish are nocturnal, choosing to feed at night when their favorite food is active. As a member of the Tetradontiformes order, the porcupine fish is believed to have evolved over the centuries from the Perciformes order. Although the porcupine fish, like many of the Tetradontiformes, are poor swimmers they have often been seen swimming with amazingly agile motions in and out of the coral reef as they search for prey.

The body of the porcupine fish is round; much like that of the puffers, but how they inflate the body is distinctly different. Unlike the puffers, the porcupine fishes do not have a special sac in the intestinal area to fill with water or air when inflating their bodies. Instead, these amazing fish take tiny gulps of water into their stomach until the body is fully extended. With the smaller of the species that have their spines always present this action gives them the appearance of an angry porcupine within seconds. In the larger species the spines lay along the body becoming prominent as the body inflates. Another of the distinct characteristics that differentiates the porcupine fish from the puffers is their incredible hunting habit. As night falls, some species of these interesting fish begin to appear from cracks and crevices within the coral reef. The move stealthily along the bottoms searching for their favorite food which is the mollusk. Just when it appears that no prey is present, the porcupine fish will move its body over a small area of sand and spurt tiny jets of water to uncover its prey. These tiny fish have a voracious appetite and when kept in an aquarium will swim to the top to await their food. In fact, some porcupine fish have even been known to spray a small stream of water at anything that moves when they are hungry.

Much like the puffers, the porcupine fish have large teeth that take on a beak-like appearance. Although the mollusk appears to be the favorite food of this fish, they are also known to eat clams, oysters and other invertebrates that dig into the bottoms of their habitat. Interestingly, claims that the spines of the porcupine fish are known to inflict a venomous sting have been made but to date no proof of these claims have been found. Since most data concerning the smaller species of this fish shows that they have been used more as shelf trinkets and to spice up the fish life of aquariums, it is highly likely that few or none have been ingested by humans. Another interesting aspect of this rather small, brown spotted fish, is that even though they are often observed in aquariums, very little is known about their mating habits or the juveniles of these species.