Pinnigrada refers to a group of marine mammals commonly known as pinnipeds, which includes seals, sea lions, and walruses. The term "pinnigrada" is derived from the Latin words "pinna" meaning fin and "gradiens" meaning walking, indicating their ability to move both in the water and on land.
Pinnigrada are characterized by their semi-aquatic nature, spending much of their time in the water but also having the ability to haul out onto land for various activities such as breeding, molting, and resting. They have streamlined bodies adapted for swimming, with elongated flippers that act as paddles for efficient movement through the water. Their flippers are also useful for navigating on land, although they are less agile on land compared to fully terrestrial mammals.
Seals, sea lions, and walruses belong to the order Carnivora and have adaptations suited for their aquatic lifestyle. They possess a thick layer of blubber that acts as insulation, helping to maintain body heat in cold water. Pinnigrada are carnivorous, feeding primarily on fish, squid, and other marine invertebrates.
These marine mammals have a global distribution, inhabiting various coastal regions and oceans around the world. They play a significant role in marine ecosystems as top predators, regulating fish populations and maintaining ecological balance. Pinnigrada are also of economic importance, as they have been historically hunted for their fur and oil. Conservation efforts are currently in place to protect and manage pinniped populations and their habitats.
