Japanese sea lion

Extinct in 1951
  • Japanese sea lion
  • Japanese sea lion

Japanese sea lion – officially not yet extinct, but in reality

Just in time for the New Year 2016, our LOST ZOO acquired a pair of the rare Japanese sea lions. Originally the Japanese sea lions lived in the Japanese Sea at the East coast of Korea, along the East and West coast of Japan, around the Kuril and Sakhalin Islands, at the South coast of Far East Russia and in the Okhotsk Sea at the Southern tips of the Kamchatka Peninsula.

Japanese sea lion, painted by Settan Hasegawa

Japanese sea lion, painted by Settan Hasegawa (Click to view larger image).

Japanese sea lions lived always near to the coastline and not in the open sea. They usually bred on flat, open, sandy beaches and rarely in rocky areas. But quite uncommon for sea lions they preferred to rest in caves.

Japanese sea lion which is painted in Edo era Hunting of the Japanese sea lion

Japanese sea lion which is painted in Edo era
(Click to view larger image).

Hunting of the Japanese sea lion
(Click to view larger image).

Less than 50 years ago there were some doubtful sightings of the Japanese sea lions and therefore they are not yet officially extinct today, although in 2007 intensive, scientific expeditions ended without any positive sighting of a Japanese sea lion. Really only a very few factors lead in the past to the extinction of the Japanese sea lions. The main reason is the persecution and hunting by fishermen who saw in the sea lion a concurrent for fishing.

Galapagos sea lion of closely related species California sea lion of closely related species

Galapagos sea lion of closely related species
(Click to view larger image).

California sea lion of closely related species
(Click to view larger image).

It is said that in the mid of the 19th century the population of the Japanese sea lions counted about 30.000-50.000 animals. Harvest records by commercial fishermen show that in the early 1900s about 3.200 Japanese sea lions were killed per year, but already in 1915 the harvest declined to only 300 sea lions. The number still declined to a dozen of sea lions at the 1930ies. In the 1940ies the commercial hunting on Japanese sea lions ended, because the species became almost extinct. In total, the Japanese hunted commercially 16.500 Japanese sea lions. A further factor can be also the marine warfare of World War II which probably contributed to the destruction of the sea lions’ habitat.

Japasese sea lion which were kept in Tennnoji zoo, Osaka Japanese sea lion on a design of manhole cover in Oki-no-shima island

Japasese sea lion which were kept in Tennnoji zoo, Osaka
(Click to view larger image).

Japanese sea lion on a design of manhole cover in Oki-no-shima island
(Click to view larger image).

Instead of several intensive search expedition to their former habitats, the Japanese sea lion could never been observed again since the late 1950ies. Last reports were given about 50-60 Japanese sea lions on the Liancourt Rocks, a small island group in the Japanese Sea just between Honshu and South Korea.

Stuffed specimen of Japanese sea lion

Stuffed specimen of Japanese sea lion (Click to view larger image).

There were still some sightings of single Japanese sea lions in the 1970ies, the last one in 1974 in northern Hokkaido. But it is not clear, if these animals are indeed Japanese sea lions or escaped Californian sea lions. At the first glimpse such a mistake seems to be astonishing, but scientists regarded for a very long time the Japanese sea lion as a subspecies of the Californian sea lion. Only after the extinction of the Japanese sea lion, modern researches in 2003 could show that the Japanese sea lion has to be separated from the Californian sea lion (Zalophus californianus ) and has to be registered as a special species Zalophus japonicus . The Japanese sea lion has a larger and a much broader skull than the Californian species and is in general slightly larger than the Californian species. Furthermore, the Japanese sea lion have six teeth behind their upper canine tooth, but the Californian sea lion only five. Later on, a gene analysis testified the difference of both species too.

Japanese sea lion enclosure in LOST ZOO

Japanese sea lion enclosure in LOST ZOO
(Click to view larger image).

Male Japanese sea lions were dark grey-brown, reaching lengths of 2.3 to 2.5 m and a weight of about 450 to 560 kg. Old males had an almost black fur. Compared with the males the females were significantly smaller reaching lengths of 1.40 to 1.64 m and had a lighter color too. In former times Japanese sea lions were popular animals in Japanese zoos like in the Tennoji Zoo in Osaka, which has still 3-4 stuffed animals in its collection. But today only stuffed animals can be found in this zoo and some other places in Japan. Also the Natural History Museum in Leiden, Netherlands, possesses a stuffed Japanese sea lion which was sent to Leiden by Philipp Franz von Siebold during his stay on Dejima Island near to Nagasaki. Because even stuffed Japanese sea lions are seldom to be seen today, we are extremely happy to exhibit this rare and interesting species in our LOST ZOO as the first new arrival in 2016.

Executive Curator
JURGEN LANGE

Japanese sea lion

Originally the Japanese sea lion and the Galapagos sea lion were only two subspecies of the Californian sea lion. Because of their distinct distribution and morphological and genetic differences all three forms are today separate species.
The Japanese sea lion lived in the coastal waters on both sides of Japan and in the Japanese Sea between Japan and Korea, always near to the coastline.

Body length: Males 230-250 cm. Females much smaller, only 140-164 cm

Body weight: 450-560 kg. The small females of course much lighter than males

Color: Dark grey-brown or black (old males), female lighter color than males.

Lifespan: about 30 years.

Extinction in the Wild: Because of overhunting the Japanese Sea Lion was driven to extinction in the 1950ies. Last sighting of 50-60 animals in 1951 on the Liancourt Rocks

Animal Exhibition
japanesesealion