Step aside, manatees. Whales may be the new cows of the sea—at least as far as their gut bacteria is concerned. According to a new study, the carnivorous sea animals and grass-chewing herbivores have similar gut microbiomes, suggesting that the bacteria in the digestive system isn’t just influenced by diet.
The study, published in Nature Communications, is based on data collected from fresh whale poop fished out of waters off the coast of Canada (a fantastic research task, to be sure). After analyzing these floating fecal samples, the researchers determined that humpback and right whales have microbiomes similar to other carnivores, but also to some herbivores.
Baleen whales eat fish, krill, and other sea creatures, so it’s surprising that they would share bacterial colonies with vegetarian, cud-chewing land animals like cows. While the whales’ poop did contain genetic traces of microbes that help terrestrial carnivores like lions digest proteins, it also had unusual parallels to the bacteria that help cows digest the cellulose in plants.
The scientists suggest that these microbes might help whales break down the carbohydrates found in the exoskeletons of their prey, including a tough-to-digest starch, chitin, found in crustacean shells.