View source for Zalophus

{{Short description|Genus of carnivores}}
{{Automatic taxobox
| image = Lion de mer Amnéville 01.jpg
| image_caption = Californian sea lion
| taxon = Zalophus
| authority = [[Theodore Nicholas Gill|Gill]], 1866
| type_species = ''[[California sea lion|Otaria gilliespii]]''<br />(now ''Zalophus californianus'')
| type_species_authority = [[René-Primevère Lesson|Lesson]], 1828
| range_map = Zalophus distribution.png
| range_map_caption = 
{{align|left|{{color box|#3B1BC6}} ''Z. californiana'' breeding range}}<br />
{{align|left|{{color box|#53A8DE}} ''Z. californiana'' total range}}<br />
{{align|left|{{color box|red}} ''Z. wollebaeki'' range}}
}}

'''''Zalophus''''' is a genus of the family [[Otariidae]] ([[sea lion]]s and [[fur seal]]s) of the order [[Carnivora]].

==Description==
The seals of the genus ''Zalophus''  present a striking [[sexual dimorphism]], since the adult males have a pronounced [[sagittal crest]], and weigh, in the Californian species, between 300 and 380&nbsp;kg with 240&nbsp;cm long, and the females 80 to 120&nbsp;kg with between 180 and 200&nbsp;cm. As with all ear seals, the males are significantly larger and heavier than the females. The males are dark brown in color, the females are lighter. In contrast to the other ear seals, the males do not have a clearly defined mane. In the Galapagos species the males weigh about 250&nbsp;kg with a length of 250 to 270&nbsp;cm, while the females weigh from 60 to 100&nbsp;kg with a length of between 150 and 170&nbsp;cm.

They have a streamlined body, with a layer of fat under the skin, to provide warmth and buoyancy. The coat is brown. They have large eyes that help compensate for low light levels in the underwater environment, while their whiskers increase their sense of touch. The nostrils close automatically once they touch the water. Their long front fins rotate outward for better movement on land, and propel them forward in the water, where they stay as long as possible.

==Systematics==
For a long time, specialists debated whether the 3 taxa that make up this genus were three full, monotypic species, or instead a single species with three subspecies; in the latter case, by priority, this species would be ''Zalophus californianus''.

As early as 1953, the zoologist Erling Sivertsen created a new indicative classification, after he investigated and catalogued again, in the Oslo Museum, skulls and archaeological remains, collected by the Norwegian expedition ship MK Norvegia between 1928 and 1929. Traditionally, the three populations were listed as subspecies of a common species, but this was controversial. Wilson & Reeder classified the three populations as separate species. A molecular genetic study by Wolf et al. (2007) came to the same conclusion based on mitochondrial DNA and cell nucleus DNA SNPs. Furthermore, according to a molecular clock reconstruction, the Californian and Galápagos sea lions separated around 2.3 (± 0.5) million years ago.

===Species===
It includes these [[species]],<ref name=WilsonReeder>Don E. Wilson & DeeAnn M. Reeder (editors). 2005. Mammal Species of the World. A Taxonomic and Geographic Reference (3rd ed), Johns Hopkins University Press, 2,142 pp. [http://www.bucknell.edu/msw3/ Online]</ref> of which one became recently [[Extinction|extinct]]:

{| class="wikitable"
|-
! Image !! Name!!  Distribution
|-
|[[File:California sea lion in La Jolla (70568).jpg|120px]] ||''Z. californianus'': [[California sea lion]]<ref name=IUCN-Cali>Seal Specialist Group 1996. Zalophus californianus. In: IUCN 2007. 2007 IUCN Red List of Threatened Species. <www.iucnredlist.org>. Downloaded on 07 March 2008.</ref> || western coast and islands of North America, from southeast Alaska to central Mexico. 
|-
|[[File:Excursion to a lagoon on the N side of Isla Santa Fe - Galapagos Sea Lion (Zalophus californianus) (16492679320).jpg|120px]] ||''Z. wollebaeki'': [[Galápagos sea lion]]<ref name=IUCN-Galapagos>Seal Specialist Group 1996. Zalophus wollebaeki. In: IUCN 2007. 2007 IUCN Red List of Threatened Species. <www.iucnredlist.org>. Downloaded on 07 March 2008.</ref> || Galapagos islands and Ecuadorian coast, north to Isla Gorgona in Colombia. 
|-
|[[File:Zalophus japonicus.JPG|120px]] ||''Z. japonicus'': [[Japanese sea lion]] †<ref name=IUCN-Japan>Seal Specialist Group 1996. Zalophus japonicus. In: IUCN 2007. 2007 IUCN Red List of Threatened Species. <www.iucnredlist.org>. Downloaded on 07 March 2008.</ref> || Japan and Korea; vagrant to southern Kamchatka Peninsula and Sakhalin Island in Russia
|-
|}

==Ecology==
These seals go to rest on the coasts. When looking for food, they dive up to 40 meters deep and prey on fish and octopus. During the breeding season, the males establish strictly guarded [[territory (animal)|territories]] on the coasts and try to gain a harem from several females.

They feed on fish and mollusks. They are very sociable and are found in large groups, on cliffs, coasts, and even on human constructions, such as piers and navigation bowls.

===Reproduction===
Unlike fur seals (''[[Arctocephalus]]'') which live in well-structured social groups, the species of the genus ''Zalophus'' form variable groups lacking in organization, although the males are also territorial and usually form [[harem (zoology)|harems]] of about fifteen females each. Males make loud sounds to mark territory. They usually [[mating|mate]] between May and January depending on the species. Females give birth to only one young, which is born on land or water after a gestation that lasts between 342 and 365 days. They are the only mammals whose milk does not contain lactose. Females wean their young after 11 to 12 months, but some nurse their one-year-old pups alongside their newborns.
<gallery>
File:Galápagos sea lions Isabela.jpg| A pair of Galápagos sea lions (Zalophus wollebaeki) on Isabela Island, Galapagos Islands. Photographed in the early morning.
File:Californian Sea Lions (16141829839).jpg| California Sea lions at Santa Cruz, California
File:Zalophus californianus swimming past fish, Guadalupe Island, Mexico (14917375665).jpg| California Sea lions (''Zalophus californianus'') swimming past fish, Guadalupe Island, Mexico
</gallery>

==References==
{{Reflist}}

==External links==
*{{Commons category-inline|Zalophus|''Zalophus''}}
*{{Wikispecies-inline|Zalophus|''Zalophus''}}

{{Carnivora|C1.}}
{{Pan-Pinnipedia|O.|state=autocollapse}}
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[[Category:Zalophus| ]]
[[Category:Carnivoran genera]]
[[Category:Taxa named by Theodore Gill]]