Wednesday, May 2, 2007

Handling a Centipede

Handling a Centipede

The painful results of a centipede bite have been well known for centuries. In 1740, the English naturalist Charles Owen wrote, "The Scolopendra is a small venomous worm, and amphibious. When it wounds any, there follows a Blueness about the affected Part, and an Itche all over the Body, like that caused by Nettles. Its Weapons of Mischief are much the same as those of the Spider, only much larger; its Bite is very tormenting, and produces not only pruriginous Pain in the Fleshe, but very often Distractions of the Minde."

The venom apparatus consists of modified legs, on either side of the body just behind the head. These are known as maxillipeds, or sometimes as forcipules. The fang itself consists of a hollow tube with a sharp tip, like a hypodermic needle. The venom glands are found inside the body wall at the base of the fangs. When the centipede attacks, muscles surrounding the venom gland squeeze it and force venom through the hollow maxilliped and into the prey's body.

Very little scientific study of centipede venoms has been done, but it is known that some centipede venoms contain the active ingredient 5-hydroxytryptamine. The venom of the North American giant centipede, Scolopendra heros, contains cytolisins which break down cell walls.

Smaller centipedes, such as the orangish Scolopocryptops specimens found under rocks throughout the northeastern United States, produce nothing more than a painful but localized reaction, similar to a bee sting. The larger tropical species found in the pet trade, however, pack more of a punch, and can produce systemic symptoms as well as severe pain at the site of the bite---some people bitten by tropical scolopendromorphs have suffered nausea, vomiting, headaches and swelling in the lymph nodes. The centipede's venom can sometimes have a necrotic effect at the site of the bite, which can produce a painful open sore that takes some time to heal.

There is only one case in the scientific literature of a human death caused by a centipede bite -- a seven year old girl in the Phillipines died after being bitten on the head by a fullgrown tropical centipede, probably the large species Scolopendra subspinipes. Despite the potential danger, however, centipedes are not considered to be a major medical concern in any of the areas where they are found. Nevertheless, be aware that your pet centipede is a venomous animal, and treat it with the respect it deserves. A small percentage of people are allergic to centipede venom, and for these people any bite, no matter how small the pede or how weak the venom, can turn into a life-threatening emergency. If you are allergic to bee stings, the chances are good that you will also experience a reaction to centipede venom.

All of the tropical centipedes should be treated with caution. They should not ever be touched or handled with bare hands. If it is necessary to handle one, to move it to another tank for instance, great care should be exercised. These animals can move very quickly and bite readily, and unlike other animals that move rapidly away from potential danger, centipedes will immediately go on the attack towards any perceived threat.

Smaller centipedes are rather delicate and should be moved carefully. The best method is to place a small container (such as a deli cup) into the tank and then "herd" the centipede into it using an artist's soft-bristled paintbrush. Once the centipede runs inside the container, snap the lid on and it will be safely confined. This method can also be used (with more care) for larger tropical centipedes. To prevent escapes, transfer operations should always be carried out in an enclosed area to prevent the centipede from getting away if it makes a break for it. A bathtub works well (make sure you plug the drain). Keep all of your fingers well out of the way. If you offer a centipede any chance to get a fang into your flesh, it will happily oblige.

Some keepers handle their centipedes using a long pair of tongs or forceps that have been padded at the tips with foam rubber (a method also used to handle scorpions). If the tongs are at least twelve inches in length, the centipede will not be able to reach up and bite you with its fangs. This method should not be used by beginners, however---the exoskeleton of a centipede is not as thick as a scorpion's, and too much pressure can rupture the centipede's body wall and cause death. Centipedes also move very quickly, and it may be very difficult to grasp the pede without causing it to shed a large number of legs. It is far safer for both you and the centipede to prod it into a suitable container using a brush.

It may be best to slow down the centipede somewhat before attempting to move or handle it. This can be accomplished by placing the entire centipede tank in the refrigerator for about fifteen minutes. Centipedes, like all arthropods, are ectotherms and are dependent on their external environment for body heat. The cooler the temperature, the less quickly they are capable of moving. Keep in mind, however, that your centipede is a tropical animal, and cooling it to unnaturally low levels like this will cause it considerable stress. It may also kill the animal if cooled too far or too long. The idea is to cool it enough to slow down its movements, not to immobilize it.

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