Seals, dusky dolphins and killer whales have also been seen. The infraorder Cetacea includes whales, dolphins and porpoises. Humpbacks are a friendly species that interact with other cetaceans such as bottlenose dolphins. The parasites have been found in dolphins and whales. Cetacea is an infraorder that comprises the 89 species of whales, dolphins, and porpoises. Dolphins and porpoises are kept in captivity. At least some wild bottlenose dolphins use tools. One type of feeding behavior seen in bottlenose dolphins is mud ring feeding. Cavitation may limit the maximum swimming speed of powerful swimming animals like dolphins and tuna. The lagoon also has a small population of the endangered Irrawaddy dolphins. These dolphins inhabit warm and temperate seas worldwide. This could threaten the existence of the endangered Irrawaddy dolphins in downstream Cambodia. This is known to fishermen, who look for dolphins to catch tuna. They have geographic rivalries with the Miami Dolphins and Tampa Bay Buccaneers. There are 40 extant species named as dolphins.