Animal Encyclopedia Category: Marine Mammals

This species feeds on schooling, mesopelagic fishes and squids in the open ocean. Like their prey, spinner dolphins form large groups – typically composed of hundreds or even thousands of individuals – for hunting and socializing. Spinner dolphins are known for being quite playful and put on impressive aerial displays, breaching and spinning regularly. Mating also occurs in groups, … Read more

The charismatic sea otter is one of the most well-known marine mammals today. The largest member of the weasel family, they can grow to be nearly 5 feet long and weigh almost 100 pounds. They spend nearly their entire life in the ocean in the temperate coastal waters on the Pacific Coast and have a … Read more

Marine otters are foraging predators that eat a wide variety of prey. While they prefer invertebrates, including crabs, clams, and other hard-shelled groups, they are also known to eat some fishes, juvenile birds, and even other mammals. They also scavenge for garbage, bringing them into close contact with people. Unlike many species of weasels, scientists believe the … Read more

Though they are quite large (up to 46 feet/14 m), gray whales feed on small benthic worms and other invertebrates. Through a unique feeding strategy known as suction feeding, gray whales bite off huge mouthfuls of soft sediments (sand or mud) from the seafloor and then constrict the muscles of their mouths and throats to force out … Read more

Interestingly, though they are enormous, fin whales are not predatory. They filter feed for tiny krill or small pelagic fishes and are totally harmless to people (other than through accidental collisions). This life history strategy is common among several large animals in the ocean, including the whale shark, the basking shark, and the other great whales. Like all … Read more

Belugas, however, are typically more solidly white than their grayish cousins. Adult belugas are also slightly larger than narwhals, reaching lengths of around 18 feet (5.5 m). Interestingly, the beluga whale is the only species of cetacean (whales and dolphins) that has a movable neck. Belugas can move their heads up and down and from side to side. … Read more

Reproductive output, however, is quite low – with females giving birth to only one calf, every other year – and the gestation period is 11 months, longer than most land mammals, including humans. Lifespan is also low, with individuals likely living no longer than approximately 25 years. Vaquitas are predatory and eat a variety of Gulf of … Read more

The southern elephant seal is one of two living species of elephant seals. These two species get their name from the trunk-like nose that males develop as they become sexually mature. Only the strongest, most dominant males win the right to mate with females, and ninety percent of males die before developing a harem. Harems defended by the … Read more

Ringed seals live most of their lives associated with Arctic sea ice. They hunt under the ice for schooling fishes (particularly the Polar Cod) and pelagic invertebrates. In addition to taking advantage of natural cracks or gaps in the ice cover, ringed seals are able to cut and maintain breathing holes, furthering their ability to both hunt … Read more

The North Atlantic right whale is one of three species of right whales (the North Pacific right whale and Southern right whale are the two other species). Like all the great baleen whales, this species can grow quite large. With lengths of up to 50 feet (15 m) and weighing up to 64 metric tonnes (140,000 pounds), the … Read more