They found that in the absence of oxygen, bloodworm gut produces the same amount of laughing gas as the whole larva, demonstrating that processes within the gut are solely responsible for the leak.

The team dissected bloodworms, placed the guts in vials, and then looked for changes in gas concentrations. These bacteria are not digested, however, and can survive in the larvae’s guts by metabolising nitrates, producing N 20 as a by-product. For food, they munch on organic material from the sediment.Īlong with their food, the larvae also ingest bacteria that live in the mud. They wriggle within these tubes in order to draw in oxygen- and nutrient-rich water through one opening and pump it out through the other. Mud munchersīloodworm larvae live in U-shaped burrows in sediment at the bottom of lakes and rivers. To test their hypothesis, they took a closer look at the bloodworm ( Chironomus plumosus), a ruby-red midge larva that is a favourite food of trout. The researchers suspected that microbial “bioreactors” in the animals’ guts might produce the gas. They found not only that N 20 is produced, but that the amount increased with time. They collected a wide range of worms, larvae and bugs, placed them in closed vials, and analysed what came off.

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