Meet a parasite that can create its own mobile nursery for its young, a parasite that is thought to be the inspiration behind the chest-bursting xenomorph in the film Alien. Meet Phronima, the pram-pushing, barrel-riding parasite.
These tiny creatures are found throughout the world’s oceans, except polar regions, swimming in open water. This sets them apart from their relatives, crabs for example, which typically stick to the safe confines of the seabed. Phronima has broken free of the sea floor, taking advantage of another sea creature, the salp, to survive in the open water.
Salps are barrel-shaped, gelatinous zooplankton which drift throughout our oceans. They may occur individually or in huge chains composed of individual salps linked together. Phronima attack these vulnerable creatures and make them their hosts. Equipped with impressive front claws, Phronima carves away their insides to leave an empty barrel structure. It then climbs inside and sails the sea from within, feeding off food and water on the go.