Water Scorpion

Nepa cincerea

Statistics

Taxonomic family: Nepidae

Length: 1.5 to 3.5 cm

Average life span: upwards of 1 year

Juvenile stage (in water): 10 to 12 weeks

Adult stage (out of water): 1 to 2 years

When To See

All year

Photo credit: Neil Phillips, Iain Reid

Habitat

These odd creatures are in fact not scorpions but belong to the true-bug sub-order, Heteroptera. They are most likely to be found in stagnant water, such as ponds, canals and impoundments (such as behind weirs) in some rivers. Water scorpions are adept hunters, using their modified pincer-like forelimbs to track down and pounce on other invertebrates, but also occasionally snacking on small fish and tadpoles.

How To Identify

They have a flattened, leaf-shaped body and a long tail which acts as a snorkel to allow breathing underwater. The large pincer-like front legs are used to catch prey.

Seen It?

Been kicking about in your local river and come across one of these invertebrates? Not sure? Share it with us at trust@forthriverstrust.org, we enjoy chatting about inverts with you.