Alex Mustard / Red Sea anemonefish (Amphiprion bicinctus) rubbing non-stinging side of tentacle of Magnificent sea anemone (Heteractis magnifica) over her freshly laid eggs. This covers them in anemone mucous and pr...

Alex Mustard / A Southern sand octopus (Octopus kaurna) digs into the sediment with its long arms at night. While many octopus dig holes, this is the only known species that forms a mucous-lined burrow complete with...

GEORGETTE DOUWMA / Vermetid worm / Worm snail (Dendropoma maxima). Vermetid gastropods are unusual snails in that they secrete the calcareous tube in which they live. This one has a operculum. They feed by trapping part...

Tim Laman / Green snail (Rhinocochlis nasuta) moving along a leaf, Gunung Palung National Park, Borneo, West Kalimantan, Indonesia

Juergen Freund / Jo Browne removes with a pipet, mucous emitted by stressed Upside-down jellyfish specimens, part of the Coral Reef census, Lizard Island, Queensland, Australia, April 2008

Peter Bassett / Moulting Southern elephant seal {Mirounga leonina} with runny nose, Dream Island, Antarctic Penninsula.

Doug Perrine / Bleeker's parrotfish male asleep in mucous cocoon at night {Scarus bleekeri} Malaysia

Mark Moffett / Golden Poison Dart Frog (Phyllobates terribilis) close-up of skin pores which poison and mucous are secreted, the secreted batrachotoxins cause irreversible muscle contractions which lead to death, Co...

Birgitte Wilms / Parrotfish (Scarus sp) sleeping, close-up of mouth parrotfish create a protective cocoon around their body by secreting mucous from their mouth, Solomon Islands

Norbert Wu / Parrotfish (Scarus sp) sleeps in protective mucous cocoon at night, Great Barrier Reef, Australia

Solvin Zankl / Princess parrotfish sleeping in mucous bubble {Scarus taeniopterus} Virgin Is,

David Hall / Parrotfish sleeping in mucous bubble at night (Scarus festivus) Indonesia. The bubble prevents predators from smelling the fish while it sleeps.