What is a "water bear"?

Tardigrades are often referred to as "water bears" or "moss piglets". They are water-dwelling, eight-legged, segmented micro-animals whose body size varies from 0.05 to 1.2 mm. They are considered as one of the invertebrate phyla, therefore they are not insects, mites or crustaceans.

These strange microscopic animals are champions of durability and can survive extremes of heat, cold, radiation, dryness, wetness, pressure and prolonged absence of oxygen and food. They have brains but no respiratory or circulatory systems.

They have probing, piercing mouth parts which allow them to penetrate plant cells or animal body walls then a sucking pharyngeal bulb enables them to ingest the internal contents of their food items.

Predators include nematodes, other tardigrades, mites, spiders, springtails, and insect larvae. These tiny aquatic animals can be found in moss, ferns, lichens, soil, beaches, dunes and other damp habitats.