The noodle-like creatures at the centre of the images are adult rat lungworms emerging from the pulmonary artery of a rat.
Credit: Helen Stockdale Walden
The rat lungworm (Angiostrongylus cantonensis) generally lives in Hawaii, where it normally relies on rat and snail hosts to complete its lifecycle but can cause problems for humans and other animals who eat an infected snail.
Infected humans usually survive, but the parasite can cause a kind of meningitis if it becomes trapped in the brain and dies there, and the meningitis in turn can cause coma or death.
Researchers have recently reported evidence that the rat lungworm is spreading among rats and snails in Florida, USA, though no human infections have been reported.