Alex Mustard / Jellyfish (Catostylus sp.) swims beneath a slick of plastic debris. Indian Ocean off Sri Lanka. Highly commended in the Environmental Report section, Montphoto competition 2019

Sue Daly / Barrel jellyfish (Rhizostoma octopus) swimming past, Sark, British Channel Islands, UK, September.

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...

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

Juergen Freund / Split level of large Purple crown jellyfish (Netrostoma setouchina) in shallows of mangroves. Mali Island, Macuata Province, Fiji, South Pacific.

Barry Bland / Fried egg jelly fish (Cotylorhiza tuberculata) Mediterranean Sea.

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

Hiroya Minakuchi / Papuan Jellyfish (Mastigias papua), Palau

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

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

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

Chris Newbert / Crown Jellyfish (Netrostoma setouchianum), Papua New Guinea