Hydrozoan

Class Name

Hydrozoa

Size

Polyps rarely more than a few centimeters, with blue bottles and Portugese Man O'Wars the exceptions.

Characteristics

• Most have complex life cycles with polyp & medusa stages

• Medusa stage usually has inwards fold at bell opening

• May be solitary or colonial

• Polyps lack internal septae

Threats

None known

Did you know?

A blue bottle primary tentacle can trail as far as 13m behind the rest of the colony.