ah! it's not just our julian can tell us about dolphins!

Pliny the Elder, in his Natural History, book nine, chapter eight, follows the opinion of Aristotle and conforms closely to his relation. Pliny says that the dolphin is the swiftest of all animals, not only of sea-creatures, but also faster than any bird and speedier than any arrow. Pliny confirms the dolphin’s remarkable speed particularly by this proof. The dolphin has its mouth, which it uses in hunting fishes, sited a long way behind its beak, almost in the middle of its belly. This must strongly hinder its swimming. Nor does the dolphin snatch fishes except turned over lying on its back. However, there is no prey at all that can escape the dolphin’s speed. The dolphin itself is quite aware of this natural gift, and either for the sake of praise or because of high spirits, it often races ships that scud under full sail. The dolphin is especially fond of human beings [φιλάνθρωπος]. Some even say it loves boys [παιδεράστην], and for this reason it is a deadly enemy to the crocodile, which hates human beings more than any other animal. Thus, the dolphin is not afraid of man, but comes right up to ships. It jumps up and plays, it will race any vessel and outstrip even those moving under full sail. In the catching of mullets in the Laternan Bay the dolphin makes it magnificently clear how he excels in speed, the power of his intellect, and finally how great a well-wisher he is to human beings. What, indeed, can I say about his unbelievable power? If he is driven by hunger, he will pursue a fish to the deepest depths, and hold in his breath a very long time. When he darts out of the water to breathe, like an arrow from a bow, he jumps up with such force that his leap has capsized many a ship of billowing sail. Therefore, what symbol could be more perfectly suited to expressing the sharp and indefatigable impulse of the mind, than the dolphin?

from Erasmus, Adagia, 'Festina Lente.'