Tony Wu / Asian sheepshead wrasse (Semicossyphus reticulatus), male in white breeding colouration. Niigata Prefecture, Honshu, Japan. June.

David Fleetham / Humpback whale (Megaptera novaeangliae), close up on tubercles on underside of chin. Hawaii.

David Fleetham / Humpback whale (Megaptera novaeangliae) spyhopping, close up on tubercles on underside of chin. Hawaii.

David Fleetham / Bumphead parrotfish (Bolbometopon muricatum), Yap, Micronesia.

Joao Burini / Close-up on the skin tubercles of a Treefrog (Scinax littoralis) with copper iridescence visible. Tapirai, Sao Paulo, Brazil. South-east Atlantic forest.

Ralph Pace / Humpback Whale (Megaptera novaeangliae) surfacing, showing bumps of unknown cause, Maui, Hawaii, image taken under NMFS Permit # 19225

Ingo Arndt / Saltwater crocodile (Crocodylus porosus) detail of skin, Northern Territory, Australia

Richard Robinson / Dorid nudibranch (Archidoris wellingtonensis) in Dusky Sound, Fiordland National Park, New Zealand.

Richard Robinson / Nudibranch (Archidoris wellingtonensis) in Dusky Sound, Fiordland National Park, New Zealand. April 2014.

MYN / Lily Kumpe / Broad-nosed weevil (Gagatophorus draco), Western Australia. meetyourneighbours.net project

Alex Mustard / Tiny (10mm) pygmy seahorse (Hippocampus bargibanti) sheltering in seafan (Muricella sp.) Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Juergen Freund / Cape Tribulation cassowary sign and speed bump sign, vandalised to a 'roadkill' before and after sign, Queensland