Feeding

Cetaceans feed on a large variety of species of all different sizes such as fish, squid, and zooplankton. Their feeding depends greatly on the adaptations of each cetacean to capture their prey.

Mysticetes

The principal feeding technique for whales is filtration of their prey through baleens. Generally in this process the organisms are concentrated before they are captured. Mysticetes can feed on microscopic organisms, such as the case of krill that are quite abundant in the water column of temperate zones. Krill are crustaceans that are an essential part of the diet of the Blue whale (Balaenoptera musculus)

Another type of microorganisms are arthropods, which are also crustaceans. These are found in the sediment of coastal waters’ ocean floor. Arthropods are the main source of prey for the Gray Whale (Eschrichtius robustus)

Bubble net feeding is another technique to capture prey, principally schooling fish. In this case, the whales swim below the aggregation of fish and let out small bubbles of air around the fish. The bubbles force the fish to group and move to the surface of the water, where in synchronization the whales push through the surface of the water with their mouths open to capture their prey. This technique has only been observed by the Humpback Whale (Megaptera novaeangliae).

Odontocetes

Odontocetes do not have the ability to feed on small organisms such as zooplankton as mystecetes do. For that reason, their prey is larger in size. Dolphins have teeth that function to trap their prey. Odontocetes generally feed in groups, this allows them to cooperate while searching and capturing prey.

The echolocation system allows members of this suborder to orient themselves in the aquatic environment and locate prey. Dolphins of the genus Stenella on the Pacific Ocean feed principally on fish, squid and sometimes crustaceans. They are reported to feed on over 40 different species of fish. Beaked whales (Ziphiidae) as well as the Sperm Whale (Physeter macrocephalus) feed primarily on squid.

This information has been obtained from the ear bone of fish and jaws of squid that have been found in the stomachs of various cetaceans. Aside from feeding on these organisms, there are some species of cetaceans such as the False Killer whale (Pseudorca crassidens) and the Orca (Orcinus orca) that are able to capture other species of cetaceans.