Eschrichtius

Eschrichtius is a genus of baleen whales in the family Eschrichtiidae. The genus is named after the Danish zoologist Johan Eschricht, who first described it in the 19th century. Today, it contains one living species, Eschrichtius robustus, commonly known as the gray whale. The North Atlantic population of gray whales is extinct; some sources historically referred to it as Eschrichtius gibbosus, but it is no longer extant and is often treated as extinct or a synonym of E. robustus.

The gray whale is native to the North Pacific Ocean, with seasonal migrations between Arctic feeding grounds and warmer shallow waters along the western coast of North America, including Baja California, where parturition and breeding occur. A historically separate Atlantic population existed but disappeared due to commercial whaling. Fossil and molecular data indicate that the genus Eschrichtius has an ancient lineage within baleen whales, with several extinct relatives known from the fossil record.

Physically, gray whales are large, with a mottled gray coloration and a rough, scarred skin often covered by barnacles and parasites. They lack a prominent dorsal fin; instead, they have a series of small dorsal bumps near the tail and a broad, paddle-shaped fluke. As baleen whales, they filter small prey from the seafloor, feeding mainly on benthic invertebrates such as amphipods and polychaetes by a suction-feeding technique.

Conservation status has improved since the era of intensive commercial whaling, and the gray whale (E. robustus) is currently listed as Least Concern by the IUCN. Ongoing threats include entanglement in fishing gear, ship strikes, and environmental changes that may affect prey availability.