Alpioniscus species

This crustacean from the Alpioniscus species was discovered during ESA's CAVES 2012 training programme. Just under 8 mm long, these animals belong to the suborder of terrestrial isopods, commonly known as woodlice.

Most crustaceans such as crabs, shrimps and lobsters live in water, while woodlice are the only group that have fully adapted to life on land.

The ancestors of the terrestrial isopods seem to have evolved from aquatic life to live on land. Surprisingly, the astronauts found a species that has returned to living in water, completing an evolutionary full circle.

The picture was taken by NASA astronaut Mike Fincke as part of the CAVES training.