DON'T PUFF ME UP!

They look like organic dirigibles of the sea, have a cute smiley face and pose no threat to humans, yet each year these wonderful and diverse fish are subjected to abuse by divers, snorklers and swimmers alike. At the best, they are caught and handled until they inflate themselves in to an almost spherical shape and, at the worst, they are caught, cleaned, dried and then inflated to make “attractive and unusual” lamp shades which, were they to know their ultimate fate would be as a talking point on someone’s coffee table, would probably provided them with little comfort. What are we talking about? Puffer fish and porcupine fish of course. PUFFER & PORCUPINE FISH As their scientific family names suggest, puffers (family Tetraodontidae) and porcupine fish (family Diodontidae) are closely related. Their form and structure are similar, but whilst the porcupine fish have large external spines, puffers have hidden spines which are only visible when the fish has puffed up). The scientific name of the puffer (Tetraodontidae) refers to the four large teeth, fused into an upper and lower plate, which are used for crushing the shells of crustaceans and molluscs, their natural prey. Unlike the four-toothed pufferfishes, porcupines have only a single plate of fused teeth in each of the upper and lower jaws, which explains the name "didontidae" or "two teeth". Puffer fish are generally believed to be the second–most poisonous vertebrates in the world, after the golden poison frog of Columbia. Certain internal organs, such as liver, and sometimes the skin, are highly toxic to most animals when eaten; nevertheless, the meat of some species is considered a delicacy in Japan, Korea and China when prepared by chefs who know which part is safe to eat and in what quantity. Some species of porcupines are also 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. Puffers and porcupines have unique and distinctive natural defenses to help compensate for their slow speed. They move by combining pectoral (the fins on the side of the fish), dorsal (located on the top of the fish), anal (located on the underside of the fish behind the anus) and caudal fins (the tail), making them highly maneuverable. The tail fin is mainly used as a rudder, but it can be used for a sudden evasive burst of speed which, if you never seen either a puffer or porcupine fish do, can come as a startling surprise. Both fish have excellent eyesight and, combined with this speed burst, is the first and most important defense against predators. Their backup defense mechanism, used if successfully pursued, is to fill its extremely elastic stomach with water until they are much larger and almost spherical in shape. Due to their spines, a hungry predator may suddenly find itself facing a spiky ball rather than a slow, tasty fish. Some predators may die from choking after swallowing a slow tasty fish that suddenly balloons in their throat, whilst other predators that successfully swallow one of the fishes may find their stomachs full of tetrodotoxin (a potent neurotoxin with no known antidote), making puffers and porcupines an unpleasant, possibly lethal, choice of dinner. This neurotoxin is found primarily in the ovaries and liver, although smaller amounts exist in the intestines and skin, as well as trace amounts in muscle. It does not always have a lethal effect on large predators, such as sharks, but it can kill humans.

Both types of fish are able to move their eyes independently, and many species can change the color or intensity of their patterns in response to environmental changes, like a chameleon. Although most puffers and porcupines are drab, many have bright colors and distinctive markings, and make no attempt to hide from predators. This is likely an example of aposematism (from apo- away, and sematic sign/meaning), in other words a warning colouration.

Sharm’s Puffers

Masked Puffer

(arothron diadematus)

The masked puffer (arothron diadematus) is an olive-green/grey fish with a black mask over the eyes and pectoral fins. During the mating season you can see these fish on the reefs in large groups, the rest of the time they are mostly solitary.

Whitespotted Puffer

(arothron hispidus)

The whitespotted puffer (arothron hispidus) is a medium sized puffer fish, light grey in color with small white spots. It also has concentric contrasting white and dark grey lines that radiate around the eyes and pectoral fins.

Giant Puffer(arothron stellatus)

The star puffer or giant puffer (arothron stellatus) is the largest of species of puffer, reaching a maximum length of 120 cm. There have been reported cases of defensive bites by the giant puffer on humans causing serious damage.

Sharm’s Porcupines

Yellowspotted Burrfish(cyclichthys spilostylus) a solitary fish that uses its strong tooth plates to open shells of its prey. Up to 34cm long with short, rigid spines over the body. The colouration of the body is dusky above and light below, the spines arising from contrasting spots (lighter above and darker below).

Porcupinefish (diodon hystrix) Up to 65cm, often found hiding inside coral or rocky reefs, and usually very timid. The porcupinefish feeds mainly on gastropods and bivalved shells (clams). Fish are friends, not footballs!

The human body has some amazing abilities and not all are logical. Under certain conditions a human body will restrict blood flow, shut down body organs, or cause a person to lose consciousness or faint. Some of these body responses, without immediate and prompt medical care, can cause immediate or long term medical problems - hardly the result the body intended.

Some people believe that, as nature intended the puffer to puff, then it is Okay to make a puffer (or porcupine fish) puff up. As has already been mentioned, the puffer’s ability to puff itself up forms part of its natural defense. It is, however, its last line of defense, i.e. when the fish has been unable to escape from a predator, and is only performed when the fish is much stressed. Also, during inflation, air can become trapped inside the fish’s body. If the trapped air prevents the fish from deflating, the puffer will die. If a puffer is frightened when out of water it will suck in air instead of water and this is also dangerous for the fish.

Puffers will also inflate themselves to keep their skin supple and to remove debris, but this is only a partial inflation and is more common in juveniles than mature specimens.

The picture on the left shows a snorkler playing a game of football with a stressed burrfish that has inflated itself. Thankfully for the fish two divers came along and removed the poor fish from the, let’s be kind here, uneducated idiot and then shepherded the fish to a nice overhang.

Just because a puffer fish can puff up, there is no reason to make one do so. Everyone should respect the marine environment and that respect should include its many denizens.