Ingo Arndt / Mastigias jellyfish (Mastigias sp) with mass of jellyfish in background, Jellyfish lake, Palau, Western Pacific Islands, Micronesia

Ingo Arndt / Mass of Mastigias jellyfish (Mastigias sp) in Jellyfish lake, Palau, Western Pacific Islands, Micronesia, March 2009

Alex Mustard / Aggregation of Golden jellyfish (Mastigias sp.) in a marine lake in Palau, the golden colour of this species comes from symbiotic algae in its tissues. Jellyfish Lake, Eil Malk island, Rock Islands, P...

Claudio Contreras,Claudio Contreras / Jellyfish, Inanuran Island, Danajon Bank, Central Visayas, Philippines, April

Michele Westmorland / Snorkeler swimming with harmless Jellyfish (Mastigias papua etpisonii), Jellyfish Lake, Rock Islands, Palau, Micronesia.

Hiroya Minakuchi / Papuan Jellyfish (Mastigias papua), Palau

Hiroya Minakuchi / Jellyfish (Mastigias sp) group swimming, Jellyfish Lake, Palau

Michael Pitts / Mastigias jellyfish {Mastigias sp.} massed at surface, Palau, Western Pacific Islands

Michael Pitts / Diver amongst Mastigias jellyfish {Mastigias sp.} Palau, Western Pacific Islands

Chris Newbert / Papuan Jellyfish (Mastigias papua) 20 feet deep, Solomon Islands

Michael Pitts / Mastigias jellyfish {Mastigias sp.} Palau, Western Pacific Islands

Michael Pitts / Mastigias jellyfish {Mastigias sp.} Palau, Western Pacific Islands