Catostylus tagi is a species of jellyfish from warmer parts of the East Atlantic Ocean and since the 2000s also found in the Mediterranean Sea.

[1][2] It is the only member of the family Catostylidae that is found in Europe,[3] and it is a common species in the Tagus estuary in Portugal.

This jellyfish has a sting that causes light pain and a skin rash, but generally poses no serious threat.

Eats both zooplankton and phytoplankton, certain crustaceans, small fish, and marine snow.

Media related to Catostylus tagi at Wikimedia Commons