Sharks are universally recognized marine predators, unmatched in terms of bloodlust. However, among them there were also "white crows" - vegetarians (to be precise - one omnivorous species). Off the southern coast of the United States, scientists have discovered a species of shark, whose "menu" is predominantly plant food.
This Sphyrna tiribo is a small-headed hammerhead or shovel shark that lives off the coast of Florida, California, Mexico and Brazil. Its characteristic feature is a penchant for plant foods, even when there is no shortage of "meat dishes". Studies by scientists from the British Royal Society showed that 62, 1% of the intestinal contents of one of the caught shovel sharks consisted of algae.
The fact that these marine animals eat algae has been known before. Scientists, first of all, were interested in the process of their digestion. To find out, the researchers put five sharks in a laboratory pool and put them on a diet of 90% plant foods (algae) and 10% squid. The movement of food through the digestive tract was monitored using the carbon-13 isotope integrated into algae.
To the surprise of scientists, after a while sharks began to gain weight, much like the baby green sea turtles, which are omnivores in the process of growing up, but becoming adults finally become vegetarians.
In the next phase of research, scientists intend to better understand the evolution of the shovel shark, as well as its relationship with other species of shark that feed on plants.