Lesson Four: Sea Lion Anatomy & Physiology
California Sea Lion Anatomy
Typically categorized into behaviors, body parts, and body coverings, the adaptations of an animal are critical to their survival. Think of some adaptations that humans have to effectively survive in our environment, like opposable thumbs and lactose tolerance! Marine mammals have a wide variety of adaptations to thrive in their marine environments.
Size: California sea lions weigh between 240 pounds (females) and 700 pounds (males) and reach 6 feet (females) to 7.5 feet (males) in length (6).
Lifespan: Sea lions typically live 20 to 30 years.
Flippers: Longer flippers in the front (fore-flippers) and shorter ones in the back (hid-flippers) help sea lions move swiftly underwater and quickly on land. If you look closely at the hind-flippers of a California sea lion, they have 5 digits with short, claw-like nails – just like human toes!
Sagittal Crest: Mature, male sea lions have a "bump" on their forehead, known as the sagittal crest. This is the most common way to differentiate males and females from a distance, though males are also typically larger than females.
Whiskers: the California sea lion has 38 whiskers, or vibrissae, on each side of its face [1]. Each whisker has its own nerve ending, making them a necessary tool for hunting prey in dark and turbid waters. Their whiskers are so sensitive, sea lions are able to use just their whiskers to differentiate both shapes and sizes of objects!
Ear Pinnae: California sea lions have external ear flaps, which is one of the most common ways to tell the difference between a seal and a sea lion.
Fur: Sea lions have a thick blubber layer, which is approximately an inch thick. Covering that blubber is tightly packed fur. Oil is secreted from a sea lion's skin that waterproofs the fur, preventing water from getting through. This combination of blubber, fur, and oil forms very efficient insulation, like a wetsuit! A sea lion maintains a core body temperature between 95 and 98 degrees, which is only slightly lower than a person's.
How to Spot the Difference: Seal & Sea Lion
PHOTOS OF SEA LIONS
PHOTOS OF SEALS
