Floris van Breugel / Tiny thimble jellyfish (Linuche unguiculata) drift with the current in the calm turquiose waters of a lagoon in Ofu, American Samoa. The window of sky is called Snell's Window, caused by refraction of...

Franco Banfi / Thimble jellyfish (Linuche unguiculata) aggregation, My Paradise Reef, Cabilao Island, Bohol, Central Visayas, Philippines, Pacific Ocean.

Franco Banfi / Thimble jellyfish (Linuche unguiculata) aggregation, My Paradise Reef, Cabilao Island, Bohol, Central Visayas, Philippines, Pacific Ocean.

Franco Banfi / Thimble jellyfish (Linuche unguiculata) aggregation, My Paradise Reef, Cabilao Island, Bohol, Central Visayas, Philippines, Pacific Ocean.

Alex Mustard / Hawksbill turtle (Eretmochelys imbricata) swimming up into the water column to feed on a bloom of Thimble jellyfish (Linuche unguiculata) in spring. East End, Grand Cayman, Cayman Islands. Caribbean S...

Juergen Freund / Sea thimble jellyfish (Linuche unguiculata), Rowley Shoals, Western Australia

Juergen Freund / Sea thimble jellyfish (Linuche unguiculata), Rowley Shoals, Western Australia

Juergen Freund / Sea thimble jellyfish (Linuche unguiculata), Rowley Shoals, Western Australia

Juergen Freund / Sea thimble jellyfish (Linuche unguiculata), Rowley Shoals, Western Australia

Doug Perrine / Sea thimble jellyfish swarming {Linuche unguiculata} Bahamas

Juergen Freund / Sea thimble jellyfish {Linuche unguiculata} Caribbean Sea

Jeff Rotman / Sea thimble jellyfish {Linuche unguiculata} schooling near surface - Caribbean Sea.