Water Scorpions | 台北市立動物園資訊網

Water scorpions in the genus Ranatra (10 spp. in North America) look a lot like underwater walkingsticks. What initially seem to be antennae stretching forward from the body are actually their grasping, mantislike (“raptorial”) forelegs, used for seizing small aquatic prey. Like all insects, there are 3 pairs of jointed legs. The slender, needlelike appendage at the tip of the abdomen is not a stinger; instead, it is a pair of half-tubes that, when held together, become a sort of snorkel. The insect, an air breather, rests hind-end-upward with the tip of this tube projecting above the water surface; thus it can stay submerged for long periods.

Nepa apiculata, another water scorpion and the only member of its genus in all of North America, has a different body shape: it is oval, flattened, and blackish; its powerful, grasping forelegs are immediately noticeable, the hind legs secondarily so. As with other water scorpions, its two-parted abdomen-tip breathing tube is long and ...