Phronima: The Movie Monster and its Mobile Home

 

Phronima is a type of crustacean that is almost entirely clear, but has gigantic eyes and long arms with nasty looking claws at the end.  In fact, Phronima is so scary-looking that it inspired the monster in the movie Aliens!  You do not have to worry about Phronima if you are out swimming in the ocean, though, because Phronima is quite small.  In fact it is only about the size of the smallest part of your thumb.  Phronima’s strange appearance is due to its lifestyle in the ocean.  Phronima seeks out and attacks jellyfish and other similar animals (like salps).  Once it has found its prey, Phronima will grab the prey with its strong claws and then eat the salp from the inside out.  Even once it has eaten all the good stuff inside the salp, it still is not done, because it does not want to waste any portion of its prey.  Instead, Phronima will use the tough outer layer of the salp as a mobile home and a nursery for its young.  It will lay its eggs in the sides of that nursery so they will be protected from many predators.  Phronima can then use its hind legs to swim this mobile nursery from place to place and since the mobile nursery and Phronima are both mostly clear, they are difficult for predators to find.  When you think about it, Phronima isn’t really a monster at all – it is just a great parent!