The blue whale is the largest animal in the world. Its life expectancy is comparable to that of a human being: between 80 and 85 years. In one day, a blue whale can swallow the caloric equivalent of what 200 men eat in one day. Solitary, the blue whale swims at a cruising speed of 20 km / h. During the day, to rest when it is not hunting, the whale practices the ballotage technique: it lets itself float on the surface of the water. Photo credit: Francesco Ungaro