Water Scorpion

This insect specimen is a water scorpion. It has been mounted on a microscope slide for viewing.

What can we see?

Front legs

Water scorpions get their name from their superficial similarity to real scorpions. The most obvious point of similarity is the adapted front legs which look like the pincers of a scorpion.

Like scorpions, water scorpions use these limbs to grab prey. But instead of a sting in the tail, the water scorpion uses its mouth to pierce and kill the prey.

Long tail

Water scorpions have a long tail in adults, which adds to their scorpion-like look. This tail is actually a snorkel, allowing them to breath from the water surface.

In nymphs (such as this one) the tail hasn’t yet grown, meaning the young have to remain close to the surface of the water.


Water scorpions are hemiptera, which are the true bugs. These beetle-like insects are defined by having piercing mouth parts, like a straw.


Water scorpions also have wings – the immature wings can be seen on this nymph.

Rear legs

The water scorpion uses its four rear legs to crawl around water plants as it is not a good swimmer.

With its adapted front legs it has six legs in total, marking it out as an insect. True scorpions have eight legs, marking them as an arachnid (the same family as spiders).


The yellow colouration on the edges of the picture are from the Canada balsam resin used to stick the specimen to the glass. It doesn’t crystalise when dry, meaning that the optical quality of the slide remains clear.

The specimen is pink because it has been dyed to make the features of its body easier to see.

Author: Lee Ismail, Curator of Natural Sciences

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