ARROW-POISON FROG

( familyDendrobatidae ) also called poison dart frog or poison arrow frog vividly coloured, poisonous frogs of the American tropics whose skin secretions some of which are used by South American tribes to coat the tips of darts and arrows. Arrow-poison frog (Dendrobates). Arrow-poison frogs are tiny, usually measuring only 15 cm (0.52 inches) long, but very conspicuous, coloured in combinations of black with bright red, yellow, pink, orange, green, and blue. They live on or near the ground, and all are members of the family Dendrobatidae, but not all the 170 frog species in this family are toxic. Arrow-poison frogs possess some of the most potent toxins known. Poison glands scattered all over the amphibians' bodies produce alkaloids that affect the nervous system. The most toxic species recorded is the bright yellow Phyllobates terribilis of Colombia, capable of injuring a person who merely touches it. The poison can be absorbed through unbroken skin and causes severe irritation. Local people do not kill this frog to extract its poison, but merely scrape their blowgun darts across its back before releasing the amphibian. Other arrow-poison frogs are not as fortunate. Several Colombian tribes use different frog species to provide the poisons with which they tip their blowgun darts. The Choco people force a sharp stick into the frog's mouth and hold it over a fire until it releases a white froth of toxic alkaloids. One frog can provide enough secretion to dip 50 darts, which will remain potent for a year. The bright colours advertising their poisons allow these frogs to hunt boldly by day, feeding on ants, termites, and other small creatures living in the leaf litter of the tropical rainforest. They breed throughout the year. The frogs lay their eggs on land in a jellylike mass that is guarded by a parent or visited and regularly moistened. The newly hatched tadpoles are transported on the back of a parent to a suitable puddle, treehole, or bromeliad. In captivity some dendrobatids can live up to 15 years.