Zalophus japonicus

Status_ne_offStatus_dd_offStatus_lc_offStatus_nt_offStatus_vu_offStatus_en_offStatus_cr_offStatus_ew_offStatus_ex_on

Taxonomy [top]

Kingdom Phylum Class Order Family
ANIMALIA CHORDATA MAMMALIA CARNIVORA OTARIIDAE

Scientific Name: Zalophus japonicus
Species Authority: (Peters, 1866)
Common Name(s):
English Japanese Sea Lion
Synonym(s):
Zalophus californianus subspecies japonicus (Peters, 1866)
Taxonomic Notes: The Japanese Sea Lion has sometimes been considered a subspecies of Zalophus californianus, Z. c. japonicus. Rice (1998) argued for the retention of Z. californianus, Z. japonicus, and Z. wollebaeki as distinct species without providing new evidence. From studies of skull morphology Brunner (2003) argued for species status for these three taxa. In addition, Sakahira and Niimi (2007) and Wolf et al. (2007) provide genetic evidence that Z. japonicus is best considered a separate species.

Assessment Information [top]

Red List Category & Criteria: Extinct ver 3.1
Year Published: 2015
Date Assessed: 2014-10-26
Assessor(s): Lowry, L.
Reviewer(s): Burkanov, V.
Contributor(s): Aurioles, D. & Trillmich, F.
Facilitator/Compiler(s): Lowry, L., Ahonen, H., Chiozza, F. & Battistoni, A.
Justification:
The species is listed Extinct because there have been no documented reports of Z. japonicus since the late 1950s, despite extensive marine mammal research effort taking place within its former range. The last credible report was 50 to 60 individuals on Takeshima in 1951 (Rice 1998). Individual sightings reported as recently as 1974 and 1975, cannot be confirmed; confusion with escaped Z. californianus cannot be ruled out.
History:
1996 Extinct
1996 Extinct

Geographic Range [top]

Range Description:

According to Rice (1998) Japanese Sea Lions formerly were known from the northwest Pacific where they occurred along the coasts of Japan, the Democratic People’s Republic of Korea, the Republic of Korea, and Russia at Sakhalin Island and southern Kamchatka. Burkanov (pers. comm.) says that the only reliable report of Japanese Sea Lions was of an animal shot in 1949 at Moneron Island in the Sea of Japan at the southwest corner of Sakhalin Island. He concludes that they occasionally occurred in the southern Kuril Islands but not at Kamchatka as Rice (1998) had stated.

Countries:
Regionally extinct:
Japan; Korea, Democratic People's Republic of; Korea, Republic of
FAO Marine Fishing Areas:
Regionally extinct:
Pacific – northwest
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:

Estimates of historical population size are not available. Over-harvesting by Japanese commercial fishermen caused a drastic decline in abundance in the early decades of the 20th century and commercial harvests ended in the 1940s when the population was virtually extinct (The Sixth Extinction Website 2014). The last confirmed report was of 50-60 animals on Takeshima Island in 1951. Individual Sea Lions were reported in the region in 1974 and 1975 but their specific identity was not verified (Rice 1998). Most authorities, including IUCN and the Society for Marine Mammalogy, consider the Japanese Sea Lion to be Extinct.

Habitat and Ecology [top]

Habitat and Ecology:

Very little information exists on the biology of Japanese Sea Lions but it is assumed that they were generally similar to California Sea Lions. It is said that male Japanese Sea Lions were dark grey and weighed 450-560 kg, reaching lengths of 2.3 to 2.5 m. Females were smaller at about 1.6 m long with a lighter colour than the males. Their rookeries were on open sandy beaches and they preferred to rest in caves (Red Data Book 1994, Shimane Prefecture 2004).

Systems: Terrestrial; Marine

Use and Trade [top]

Use and Trade: Japanese Sea Lions were harvested for their skins, whiskers, internal organs, and oil, and were also captured for the circus trade. The species is now Extinct.

Threats [top]

Major Threat(s):

Japanese Sea Lions were harvested for their skins, whiskers, internal organs, and oil, and were also captured for the circus trade. Those takes, in combination with persecution by fishermen and perhaps shooting by soldiers, likely caused their extinction (Wikipedia 2014).

Conservation Actions [top]

Conservation Actions:

Japanese Sea Lions are likely to now be Extinct. However, South and North Korea, Russia, and China have indicated that they will collaborate on bringing back the Japanese Sea Lion in the Sea of Japan. That effort would involve searching Russian and Chinese waters and if animals are found some would be taken to the Sea of Japan. If not, California Sea Lions might be translocated from the United States (The Extinction Website 2014).

Bibliography [top]

Brunner, S. 2003. Fur seals and sea lions (Otariidae): identification of species and taxonomic review. Systematics and Biodiversity 1: 339-439.

Brunner, S. 2004. Fur seals and sea lions (Otariidae): identification of species and taxonomic review. Systematics and Biodiversity 1: 339-439.

IUCN. 2015. The IUCN Red List of Threatened Species. Version 2015.2. Available at: www.iucnredlist.org. (Accessed: 23 June 2015).

Red Data Book. 1994. Zalophus californianus japonicus (Peter, 1866). Japan Available at: http://www.biodic.go.jp/.

Rice, D.W. 1998. Marine Mammals of the World: Systematics and Distribution. Society for Marine Mammalogy, Lawrence, Kansas.

Sakahira, F. and Niimi, M. 2007. Ancient DNA Analysis of the Japanese Sea Lion (Zalophus japonicus japonicus Peters, 1866): Preliminary results using mitochondrial control-region sequences. Zoological Sciences 24: 81-85.

Shimane Prefecture. 2004. Zalophus californianus japonicus. Japan Available at: http://www1.pref.shimane.lg.jp/.

The Sixth Extinction Website. 2014. Japanese sea lion. Available at: www.petermaas.nl/extinct/speciesinfo/japanesesealion.htm. (Accessed: 19 October 2014).

Wikipedia. 2014. Japanese sea lion. Available at: www.en.wikipedia.org/wiki/Japanese_sea_lion. (Accessed: 19 October 2014).

Wolf, J.B.W., Tautz, D. and Trillmich, F. 2007. Galapagos and Californian sea lions are separate species: genetic analysis of the genus Zalophus and its implications for conservation management. Frontiers in Zoology 4: doi:10.1186/1742-9994-4-20.


Citation: Lowry, L. 2015. Zalophus japonicus. In: The IUCN Red List of Threatened Species. Version 2015.2. <www.iucnredlist.org>. Downloaded on 31 August 2015.
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