The oceans cover 71% of the planet’s surface, which measures around 139 million square miles (360 million square kilometers) of salty, blue water.
It is generally accepted that it is impossible to fully explore all the oceans and learn about their content, both living and non-living, due to how wide and deep these waters are.
Despite this, there has been significant progress over the years in identifying and documenting sea creatures and other fascinating finds.
One such discovery was made in the 18th century when sea lions were first discovered.
These fascinating creatures are semiaquatic pinnipeds and belong to the family Otariidae.
Sea lions and a few other species make up the group known as “eared seals.”
Sea lions are identified by their large fore flippers and readily apparent little ear flaps.
Their average size usually depends on the species and their proximity to food, but the average male sea lion weighs at least 200 pounds more than its female counterpart.
Despite several attempts from different professional bodies, the population of sea lions continues to reduce drastically due to hunting and other human activities.
In this article, you will get to know the 7 types of sea lions, both extant and extinct.
1. California Sea Lion
The California sea lion, or Zalophus californianus, is a species of sea lion native to western North America.
Their general habitats cover parts of Mexico, Alaska, and the Gulf of California.
This species is sexually dimorphic, and like most sea lions, the males are significantly larger than the females.
Of all the sea lion species, the California sea lions are considered the most friendly and easily domesticated.
They can be found in aquariums and zoos.
Being sexually dimorphic, both sexes of the California sea lion differ in ways not directly involved in reproduction.
In other words, male and female California sea lions differ in size, color, shape, etc.
Male California sea lions can weigh as much as a thousand pounds, and sometimes more, and they can grow up to almost nine feet long.
On the other hand, females typically weigh around 200 pounds and reach lengths of six feet.
These creatures are carnivorous and tend to feed on a variety of seafood.
Common animals that complete their diet include squids, clams, and fish.
This species tends to eat in groups and often cooperates with other large sea creatures, such as dolphins when hunting for food.
Despite the declining population of sea lions worldwide, the International Union for Conservation of Nature (IUCN) lists this species as “Least Concern” due to its sizable and expanding population.
2. Galapagos Sea Lion
Otherwise known as Zalophus wollebaeki, the Galapagos sea lion is native to the islands of the Galapagos and some parts of Isla de la Plata off of mainland Ecuador.
They are one of two kinds of seals that thrive in the Galapagos, but they belong to the family of eared seals because of their external ear pinnae.
Unlike the California sea lion, the Galapagos sea lion is significantly smaller, even though there is still a level of sexual dimorphism between the males and females.
Males can weigh as much as four times more than the average female, but this species usually reaches anywhere between five and eight feet long and weighs between 110 and 880 pounds.
The males are distinguished from the females by the noticeable hump on their forehead.
Each individual of this species has brown or gray fur, with females often being lighter than males and the young being a chestnut brown color.
On beaches where females reside, male Galapagos sea lions frequently maintain territories, and the more powerful a male is, the more territory and females he has.
Sea lions from the Galapagos Islands spend their entire lives there and hardly ever migrate.
They frequently eat sardines and have been observed traveling up to 15 kilometers inland to forage.
3. Japanese Sea Lion
The Japanese sea lion became extinct in the 1970s, but before then, it was considered a subspecies of the California sea lion.
Otherwise called Zalophus japonicus, this species was mostly hunted for commercial reasons, leading to its extinction.
It was not until 2003, years after its extinction, that the Japanese sea lion was recognized as a distinct species, even though it had previously been called a subspecies of the California sea lion.
There is not much information regarding the Japanese sea lion’s appearance, but its other name, the black sea lion, reveals that adult males had a gray or dark color while females had a lighter color akin to brown.
The males are said to have reached lengths between seven and eight feet, weighing between 990 and over 1200 pounds.
On the other hand, female Japanese sea lions were significantly smaller, between five and six feet long, and weighing around 260 pounds.
Despite being known as the Japanese sea lion, the animal ranged beyond Japan’s coastal region.
This specimen’s native habitat was the Northwest Pacific, primarily in Japan, Korea, and the Russian island of Kamchatka.
Unlike other sea lion species, Japanese sea lions enjoyed spending their time in caves rather than on the beach.
4. Steller Sea Lion
The Steller sea lion, otherwise called Steller’s sea lion or the northern sea lion (Eumetopias jubatus), is a sea lion species that can be found in the Northern Pacific.
The largest of the eared seals and the only member of the genus Eumetopias, the Steller sea lion is named after the scientist Georg Wilhelm Steller, who originally described them in 1741.
Male Steller sea lions can weigh between 990 and 2,470 pounds and grow to lengths of nine to 10 feet.
They have substantially bigger chests, necks, and general forebody anatomy. Females average between eight and nine feet long and weigh as much as 770 pounds.
Their pups are born weighing around 51 pounds and are black.
Adult Steller sea lions are lighter than their pups, from blonde to reddish.
In the past, Steller sea lions were widespread along the North Pacific Ocean’s coast.
They were hunted by both natives and European settlers for their flesh, skins, oil, and other items.
The carnivorous Steller sea lions hunt and eat primarily at night, feeding on more than a hundred different fish.
Depending on the availability and distribution of prey species, their diet varies throughout their range and the year.
5. Australian Sea Lion
The Australian sea lion (Neophoca cinerea) is the only native sea lion species found in Australia.
The Australian state and federal governments have passed laws protecting sea lions, and the IUCN has classified them as endangered.
According to the United Nations Environment Program (UNEP), their remnant populations are low, making them one of the most endangered pinnipeds in the entire world.
Australian sea lions have stocky bodies, large heads, and short narrow flippers.
Males weigh between 550 and 660 pounds and reach around eight feet long.
Females do not weigh as much as males; they usually average 230 pounds and reach six feet long.
The males are dark-brown with yellow patches on their necks and tops of their heads, while females have a cream-colored underside and a back that ranges in hue from silver-gray to light tan to dark brown.
They extend from western Australia to islands in the south of the country, and the largest concentrations are in southern Australia on Kangaroo Island and Hazardous Reef.
These creatures are opportunistic foragers. Although little is known about the Australian sea lions’ nutrition, it is most likely that fish, crabs, and cephalopods make up most of their diet.
Some information suggests that they also occasionally take penguins.
6. South American Sea Lion
Also called the southern sea lion and the Patagonian sea lion, the South American sea lion (Otaria flavescens) is the only species of the genus Otaria and can be found on the western and southeast shores of South America.
The IUCN Red List estimates that there are roughly 445,000 sea lions in South America overall, including about 222,500 mature animals.
As such, the species is classified as “Least Concern,” and its numbers are stable.
One of the largest and most sexually dimorphic-eared seals is the South American sea lion.
Males can grow up to 9.8 feet long and weigh 770 pounds, while females can grow to 6.7 feet long and weigh 330 pounds.
Males have full manes and a dark brown dorsal and ventral coat that ranges from dark-yellow to gold.
On the other hand, females’ lighter coats can be pale brown to yellow and occasionally feature light patterns on the head.
South American sea lions are carnivorous. Depending on the abundance in the area, they eat fish, cephalopods, crabs, and other invertebrates.
Sea lions from South America live by the water’s edge and on beaches.
These beaches typically consist of stones, rocks, gravel, or sand.
A social and diurnal species, South American sea lions live in packs consisting of several females and one or more males who guard their area.
7. New Zealand Sea Lion
The New Zealand sea lion (Phocarctos hookeri), or Hooker’s sea lion, is a species of sea lion that is endemic to New Zealand.
This species was called Hooker’s sea lion in honor of Sir Joseph Hooker, a botanist who was part of an expedition that arrived in Auckland in 1844.
This species primarily nests on New Zealand’s Campbell and Auckland islands, though it has recently been gradually recolonizing the South and Stewart islands’ coasts.
They exhibit strong sexual dimorphism, like all sea lions.
Adult males are 7.9-11.5 feet long and weigh 710–990 pounds, while mature females measure 5.9–6.6 feet long and weigh 200–350 pounds.
Mature females have coats that range from light to creamy gray with deeper coloring around the muzzle and flippers, whereas adult males have a blackish-brown coat with a black mane of coarse hair that reaches the shoulders.
The habitat tolerance of New Zealand sea lions is broad, ranging from 400m above sea level to hills, forests, and fields to dives as deep as 600 m.
Nonetheless, most prefer staying on sandy beaches and hunting primarily in areas no deeper than 200 meters below sea level.
New Zealand sea lions are carnivorous and consume smaller animals, including fish, seabirds, and crustaceans.
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