Georgette Douwma / Upside down jellyfish (Cassiopeia andromeda) Lembeh, Sulawesi, Indonesia.

Claudio Contreras / Upsidedown Jelly (Cassiopea frondosa), Jardines de la Reina / Gardens of the Queen National Park, Caribbean Sea, Ciego de Avila, Cuba, January

Constantinos Petrinos / Jellyfish carry crab (Ethusa sp.) carrying Upside-down Jellyfish (Cassiopeia andromeda). Lembeh Strait, North Sulawesi, Indonesia.

Pete Oxford / Mangrove upsidedown jelly (Cassiopea xamachana) Lighthouse Reef Atoll, Belize.

Georgette Douwma / Upside down jellyfish (Cassiopeia andromeda) on sea bed with algae. Lembeh, Sulawesi, Indonesia.

Pete Oxford / Upside-down Jellyfish (Cassiopea xamachana), Lighthouse Reef, Belize

Pascal Kobeh / Upside-down jellyfish (Cassiopea andromeda), Maldives, Indian Ocean.

Hiroya Minakuchi / Upside-down Jellyfish (Cassiopea sp), Japan

Alex Mustard / Jellyfish carry crab (Ethusa sp) carrying an upside down jellyfish (Cassiopeia andromeda) at night. Komodo Island, Komodo National Park, Indonesia. Flores Sea.

Christian Ziegler / Upside-down Jellyfish (Cassiopea xamachana) floating between the aerial roots of Red Mangrove (Rhizophora mangle), Twin Cays, Carrie Bow Cay, Belize

Pete Oxford / Upside-down Jellyfish (Cassiopea xamachana), Bonaire, Netherlands Antilles, Caribbean

Pete Oxford / Upside-down Jellyfish (Cassiopea sp), Jardines de la Reina National Park, Cuba

Pete Oxford / Upside-down Jellyfish (Cassiopea sp), Jardines de la Reina National Park, Cuba

Pete Oxford / Upside-down Jellyfish (Cassiopea sp), Jardines de la Reina National Park, Cuba

Pete Oxford / Upside-down Jellyfish (Cassiopea sp) pair on ocean floor, Jardines de la Reina National Park, Cuba

Georgette Douwma / Upside down jellyfish (Cassiopeia andromeda) on sea bed, Rinca, Komodo National Park, Indonesia, October

Norbert Wu / Upside-down Jellyfish (Cassiopea xamachana) with symbiotic Algae (Zooxanthellae) in body, Caribbean

Norbert Wu / Upside-down Jellyfish (Cassiopea xamachana) lies on bottom, symbiotic algae (Zooxanthellae) in body, Caribbean

Norbert Wu / Upside-down Jellyfish (Cassiopea xamachana) in rare landlocked lake, Kakaban Island, Borneo

Christian Ziegler / Upside-down Jellyfish (Cassiopea xamachana), Bastimentos Marine National Park, Bocas del Toro, Panama

Pete Oxford / Upside-down Jellyfish (Cassiopea sp), Jardines de la Reina National Park, Cuba

Pete Oxford / Upside-down Jellyfish (Cassiopea sp), Jardines de la Reina National Park, Cuba

Pete Oxford / Upside-down Jellyfish (Cassiopea sp), Jardines de la Reina National Park, Cuba

Joel Sartore / Photo Ark / African upside-down jellyfish (Cassiopea depressa) moving 'bell', Oklahoma Aquarium. Captive.

Joel Sartore / Photo Ark / Two Inverted jellyfish (Cassiopea xamachana) underside portrait, Loro Parque's Aquarium, Tenerife. Captive.

David Fleetham / An Upside-down jellyfish (Cassiopea medusae) washed ashore at high tide and likely to die when the ocean recedes, Yap, Micronesia.

David Fleetham / Mangrove upsidedown jellyfish (Cassiopea xamachana), Florida, USA. This species mimics sea anemones by resting with its tentacles positioned on top when on the sea floor.

Willem Kolvoort / Jellyfish pool on Picard Island, home to Upside down jellyfish (Cassiopea sp). The water is very muddy but there is underground connection with the lagoon of Aldabra, Picard Island, Aldabra, Indian Oc...

David Fleetham / Upsidedown jellyfish (Cassiopea medusae) is resting bell down, tentacles up, on sandy bottoms off Wakaya Island, Fiji.