Another great amusement of the Romans was the _venatio_, or exhibit of wild animals. The first known display of wild animals at Rome was given by Marcus Fulvius Nobilior, the conqueror of Ætolia, in 186 B. C., eighty years after the first gladiatorial exhibit. These displays grew until all parts of the world were searched to find animals. There were bears, elephants, deer, hares, stags, boars, bulls, crocodiles, hippopotamuses, rhinoceroses, lynxes, apes, giraffes, tigers, ostriches, hyenas. They were made to fight with one another. They were starved to make them fierce with hunger and then driven into the arena against one another with whips, pricked with lances, burnt with hot irons, and in other ways tormented to make them extremely angry. There were also fights between men and beasts. These were often captives and criminals compelled to fight, but there were others, _bestiarii_, who were trained, as the gladiators, in schools to fight against animals. These men sometimes were assisted by dogs trained to hunt and to fight wild animals. In some exhibits, captives and criminals were bound to stakes and animals set upon them or they were sent unarmed or poorly armed against the wild animals. There were, too, exhibits of trained animals and animal-training became a regular profession under Augustus. Another form of the spectacle for the entertainment of the Roman public was the _naumachia_, or naval battle. As in the other contests, usually the combatants were captives and criminals. These were held in the amphitheater, in which case the arena was flooded with water, or great ponds were dug for the purpose. The first naval battle on a large scale was given by Julius Cæsar in 46 B. C., the two sides having biremes, triremes, and quadriremes, with 1,000 marines and 2,000 oarsmen on each side. Claudius in 52 A. D. gave a naval contest in which there were 100 triremes and quadriremes and 19,000 warriors and oarsmen. Other large naumachiæ were produced by Augustus, Nero, Titus, and Domitian. In these conflicts real fighting took place and large numbers were killed.