Gray whale

The gray whale, known scientifically as *Eschrichtius robustus*, is a massive marine mammal.

It is a baleen whale, which means it uses specialized plates to filter food. These whales are famous for their long migrations between feeding and breeding grounds. They are distinctive because of their dark slate-gray skin. This skin is covered in white mottling and gray patches. These patterns are actually scars left by parasites. These parasites drop off when the whale enters cold feeding waters.

Gray whales have a very unique physical structure. Unlike many other whales, they lack a dorsal fin on their backs. Instead, they possess a dorsal ridge. This ridge consists of 6 to 12 raised bumps called dorsal crenulations, or "knuckles."

These knuckles lead down the midline of their rear toward the flukes. Their tail flukes are quite large, measuring about 4.57 meters across. They are also deeply notched in the center. While they usually swim at a slow speed of 4.8 kilometers per hour, they can accelerate if they feel threatened.

The feeding mechanism of the gray whale is quite specialized. They are baleen whales, meaning they do not have teeth. Instead, they have cream or blond-colored plates called baleen.

These beard plates can reach lengths of up to 0.76 meters.

The whale uses these plates to filter tiny organisms from the water. Their throat also lacks the deep furrows found in related rorqual whales. Instead, the ventral surface of the throat has only two to five shallow furrows. This anatomy helps them process food as they move through the ocean.

Taxonomy, or the science of naming living things, has been complex for this species.

In 1865, John Edward Gray placed the whale in its own genus, *Eschrichtius*. He named it to honor the zoologist Daniel Frederik Eschricht. For a long time, scientists thought the Atlantic and Pacific whales were different species. In 1869, Cope described the Pacific species as *Rhachianectes glaucus*. However, skeletal comparisons in the 1930s proved they were the same. This discovery helped clear up a century of scientific confusion.

There are two primary populations of gray whales in the Pacific Ocean. The eastern population is much larger, with about 27,000 individuals. These whales migrate between northern Alaska and Baja California Sur. Mothers often swim in shallow kelp beds to protect their calves. They are known to fight aggressively to defend their young. This behavior led some people to call them "devil fish."

The western population is much smaller and lives near the Sea of Okhotsk and Sakhalin Island.

While this group was once critically endangered, their numbers have recently begun to increase.

The history of the gray whale in the Atlantic is a story of loss.

These whales once lived in the North Atlantic, including the Baltic Sea and the Mediterranean. However, they were extirpated, or locally extinct, from these areas. This happened in the Atlantic coasts of America and Africa between the late 17th and early 18th centuries. Scientists believe whaling may have caused this decline. A study from 2025 suggests they also disappeared from the eastern North Atlantic between the 12th and 14th centuries. This coincided with the end of the Medieval Warm period and a rise in medieval whaling.

Gray whales are remarkable for their longevity and size. An adult can reach a length of 14.6 meters. They can also weigh as much as 36,000 kilograms. Most gray whales live between 55 and 70 years. However, one female was estimated to have lived between 75 and 80 years.

Even though they are the ninth largest type of cetacean, they remain a vital part of the marine ecosystem. Their movements and life cycles connect different parts of the Pacific Ocean through their massive migrations.