Giant Porcupine Fish (Diodon nicthemerus) caught at Puerto, a sunken pier, Sto Domingo Ilocos Sur. Photos by Marlo R Rotor, 2008. Porcupinefish belongs to Family Diodontidae, Order Tetraodontiformes, and Class Actinopterygii.
Free swimming porcupine fish in its normal body shape. Porcupinefish have the ability to inflate their body by swallowing water or air, thereby becoming rounder. Porcupinefish are medium to large sized fish, and are found in shallow temperate and tropical seas worldwide. Photo credit to Wikipedia.
Ode to the Porcupinefish
I saw a hedgehog before I found you
In a lush forest many years past;
Are you the extinct resurrected one
Of a lost world, now an outcast?
Spartan and venomous you stand
On Darwin's side to be fit to live.
Lo! my new friend, nothing outwits man,
The sapiens after Adam and Eve.
Go, go into the hadal depth of the sea,
Far, far off from any nation,
Tierra del Fuego, Sargasso Sea,
In Poseidon's final bastion.
Until man on earth is finally gone.
And the world once more is one. ~
Porcupinefish are fish also called blowfish, balloonfish and globefish. They are sometimes confused with pufferfish. Porcupinefish are closely related to pufferfishes but porcupinefish have heavier spines (hence the name porcupine) on their body. Also unlike the pufferfishes, they have only a single plate of fused teeth in each of the upper and lower jaws.
This increase in size (almost double vertically) reduces the range of potential predators to those with much bigger mouths. A second defense mechanism is provided by the sharp spines, which radiate outwards when the fish is inflated. Some species are poisonous, having a tetrodotoxin in their internal organs, such as the ovaries and liver. This neurotoxin is at least 1200 times more potent than cyanide.
Some scientists believe the poison is produced by several types of bacteria that are somehow obtained via the fish's diet, because fish bred in captivity are not poisonous. However, other scientists are skeptical of this theory. As a result of these three defences, porcupinefish have few predators, although adults are sometimes preyed upon by sharks and orcas. Juveniles are also preyed on by tuna and dolphins.