[waw-ter-skawr-pee-uh
n, wot-er-] 
| any of several predaceous aquatic bugs of the family Nepidae, having clasping front legs and a long respiratory tube at the rear of the abdomen: capable of biting if handled. |
| water scorpion n. Any of various aquatic insects of the family Nepidae, having a large breathing tube projecting from the posterior part of the abdomen and inflicting a painful sting. |
water scorpion
any of the approximately 150 species of aquatic invertebrates of the family Nepidae (order Hemiptera). The water scorpion resembles a land scorpion in certain ways: it has scythelike front legs adapted for seizing prey and a long, thin, whiplike structure at its posterior end. This "tail," made up of two attached respiratory tubes, is extended above the surface of the water, enabling the animal to take in air. The bite of the water scorpion is painful but is far less harmful to humans than the sting of the true scorpion.
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