Cetaceans includes whales, dolphins and porpoises. These are the cetaceans (whales, dolphins and porpoises). Bottlenose dolphins and harbour porpoises are also sighted in the Thames. Basking sharks, minke whales, porpoises, and dolphins are among the sea life nearby. Resident killer whales swim alongside porpoises and other dolphins. The infraorder Cetacea includes whales, dolphins and porpoises. The order Cetacea includes whales, dolphins and porpoises. Predators include dolphins, tuna, marlin, birds, squid, and porpoises. The order Cetacea includes whales, dolphins, and porpoises. Dolphins and porpoises are kept in captivity. This order includes whales, porpoises, and dolphins. Cetacea is an infraorder that comprises the 89 species of whales, dolphins, and porpoises. There are no limits on pilot whales and porpoises. Porpoises and blue whales gestate for about 11 months. Harbour porpoises prefer temperate and subarctic waters.