Large, light sensitive eyes Light producing organs for protective evasion, attraction of prey, and mate selection. Representative deep-sea fish cyclothones and lantern fish may be the most abundant mesopelagic fish. That's where food comes from. This species also solves the problem of reproduction by having the male as a parasite attached to the body of the female. Dolphins, porpoises, and some of the whales are fast-swimming predators.
Baleen whales are filter feeders.
Other Marine Mammals Pinnepeds include seals, sea lions, and walruses. Like the cetaceans, pinnepeds also evolved from a common terrestrial carnivore. They are found in mid-latitude and polar oceans. Pinnepeds cannot spend long periods of time under-water. Manatees and dugongs are tropical herbivores.