Photosynthesis is the process by which many plants, algae, bacteria and some fungi produce energy from sunlight. Now for the first time, scientists have also discovered a photosynthesis-like process inside of an insect, according to Nature.
It turns out this super-insect is the fairly common pea aphid, a bug with a medley of bizarre characteristics that include occasionally being born without a mouth, and other times being born already pregnant. A recent study on the oddball also discovered that it seems to produce high levels of homegrown pigments called carotenoids.
This is a strange fact for a couple of reasons. First of all, no other animal is known to produce its own carotenoids. To the extent that they are found in animals and play a part in animal biology, it is only due to the fact that many animals consume these pigments in their diets. Second of all, carotenoids are an important part of the photosynthesis machinery in many photosynthetic organisms.
Operating on a hunch, researchers at the Sophia Agrobiotech Institute in Sophia Antipolis, France, set out to test whether the pea aphid might be tapping into the photosynthetic process too. They began by testing the levels of ATP — the substance that transports chemical energy within cells for metabolism — that are present within aphids. It turns out that the insects with the most carotenoids also contained the most ATP.
Even more telling, aphids that were placed in the light produced more ATP. When the same insects were placed in the dark, their ATP production decreased. In other words, it would seem that the aphids were using their carotenoids to produce energy from the light.
If this is true, the pea aphid would be the first insect in the world known to harvest sunlight for energy. The only other animals known to take advantage of photosynthesis or a photosynthesis-like process are some species of coral, and one unique species of salamander.
A few of the aphids in the study had to be crushed so that scientists could confirm that it was indeed their carotenoids that were responsible for the absorption of light, a small sacrifice in the pursuit of science. After those results confirmed carotenoids as the culprits, it was clear that something unique was going on.
Researchers did note that more research needed to be done before it could be declared that the bugs were definitely photosynthetic. It's also possible that the aphids have evolved some other photosynthesis-like process unique in nature. Either way, it's an exciting find.