Giant plumose anemones can be found all along the coast of the Pacific Northwest. This carnivorous, ghostly white species pretty much dominates its ecosystem. However, not much is known about it, especially its diet. This is because unlike other sea anemones, this species does not use long, thick tentacles to capture its prey. Instead, it has a dense bouquet of very small feelers floating around.
In order to identify exactly what these anemones were eating, researchers retrieved the mushy contents of their stomachs. However, the materials inside the stomach were so finely digested that it would have been hard to identify them using a microscope, so the researchers instead used DNA barcoding. DNA barcoding isolates pieces of the DNA within the material and then compares it to known DNA in existing databases in order to match the species from which the digested material comes from.
The researchers found what you would expect at first – barnacles, copepods, crab larvae, etc. However, there were some curious traces of DNA that fascinated the scientists from insects such as beetles, bees, and flies, with 98% of the insect DNA found in the stomach of the anemones coming from the yellow meadow ant.
Most of the organisms that were found in the gut of the anemones do spend either their entire lives, or the initial parts of their life cycle, under water, but ants do not, so the researchers came up with a theory. Ants create new colonies using a separate caste called alates. These alates are winged ants, and they take to the sky, male and female, to mate and look for a new nesting location. After mating, the females will start the nest, but the males of this particular species have nothing else to do but die off. Since these ants live on the coast, a lot of males will die above the water, or be blown over the nearby ocean after they have died on the shore. Then they will gently float down until they reach the anemones.
It is a bit unusual, but not uncommon for aquatic predators to eat terrestrial insects. In fact, you have species of anemones that are large and widespread enough to have an even more diverse diet, which includes everything from sandwich crusts to entire rabbits. These feeding patterns go to show how an entire ecosystem balances itself so that the energy contained in the organisms inside it does not go to waste.