Zoo Stock Species and the Red List
Zoo Stock Species and the Red List
Zoo Stock
This indicates that the species is included in the Second Zoo Stock Plan, which was formulated by the Tokyo Metropolitan Government in 2018. The plan sets goals for the next 10 years in three areas: "species conservation," "contribution to wildlife conservation," and "environmental education and conservation awareness." 124 animal species are included.
What is the Red List?
Based on scientific research, this is a list of wildlife classified by rank (category) indicating the degree of risk of extinction.
Livng Things Encyclopedia shows the categories (mainland and islands) assessed by the IUCN (International Union for Conservation of Nature) at the global level, the Ministry of the Environment for Japan, and the Tokyo Metropolitan Government for Tokyo.
The higher the category in each table, the higher the risk of extinction, and CR, EN, and VU are the three categories known as "endangered species." In Tokyo, species that are not at the NT (near threatened) level but are relatively rare are considered "species of concern."
|
IUCN categories |
|
|---|---|
|
EX |
extinction |
|
EW |
Extinction in the wild |
|
CR+EN |
— |
|
CR |
Serious crisis |
|
EN |
crisis |
|
VU |
emergency |
|
NT |
Near Threatened |
|
LC・○ |
Low Concern |
|
DD |
Data shortage |
|
LP |
— |
|
Japan (Ministry of the Environment) Category |
|
|---|---|
|
EX |
extinction |
|
EW |
Extinction in the wild |
|
CR+EN |
Endangered species |
|
CR |
Critically Endangered |
|
EN |
Endangered species |
|
VU |
Endangered species |
|
NT |
Near Threatened |
|
LC・○ |
— |
|
DD |
Lack of information |
|
LP |
Endangered |
|
Tokyo Category |
|
|---|---|
|
EX |
extinction |
|
EW |
Extinction in the wild |
|
CR+EN |
Endangered species |
|
CR |
Critically Endangered |
|
EN |
Endangered species |
|
VU |
Endangered species |
|
NT |
Near Threatened |
|
LC・○ |
Unranked |
|
DD |
Lack of information |
|
LP |
Endangered |
Creatures at Ueno Zoo
Creatures at Ueno Zoo
Land Snail
Mandarina hirasei
Land Snail
Mandarina hirasei
This species is endemic to the Ogasawara Islands, located about 1,000 km south of central Tokyo. There are about 100 species of snails living on the Ogasawara Islands, of which over 90% are endemic. Among them, Land Snail snail is characterized by its relatively large size and hard shell. The precious snail species of the Ogasawara Islands are declining in number, mainly due to invasive species.
| classification | Gastropoda, Eurasian Moorhen Family Hemicidae |
|---|---|
| English name | Land Snail |
| distribution | Japan (Southern Chichijima Island in the Ogasawara Islands (almost extinct), Tatsumi Island) |
| Residence | From the treetops to the ground in a forest where Pandanus and Boninus trees grow |
| Size |
Shell length: 13.0mm
Shell diameter: 21.0mm |
| food | plant |
| Red List |
IUCN: DD (Data Deficient)
Japan: CR+EN (endangered species) Tokyo: CR+EN (endangered species) |
Semi-arboreal lifestyle
Snails have evolved to adapt to various island environments, such as on the ground, in the soil, and in trees, and have increased their species. Land Snail lives a semi-arboreal lifestyle. In the exhibit case, you can observe some crawling on the ground, and others climbing on tree branches and the walls of the case.
Relationship with World Natural Heritage Sites
The Ogasawara Islands were registered as a World Heritage Site in June 2011. One of the reasons for the selection is the evolutionary diversity of the approximately 100 species of snails, including Land Snail. Having somehow reached the oceanic islands of the Ogasawara Islands, where natural enemies and competitors are limited, snails evolved to adapt to the various environments and rapidly increased their numbers. The Ogasawara Islands are truly a snail paradise.
Threat of extinction
The snails of the Ogasawara Islands are currently at risk of extinction. The main reason for this is predation by invasive species such as the New Guinea flatworm and the brown rat, which are not native to the Ogasawara Islands. It is not clear how these invasive species arrived on the islands, but it is highly likely that they have migrated along with human activity.
Protecting the Ogasawara Islands' Mai-nai
The four Tokyo Metropolitan Zoos and Aquariums are working to conserve four species of Land Snail genus, which are on the verge of extinction. They are breeding them in captivity while maintaining genetic diversity, and are also conducting research that can only be done in captivity, gathering scientific knowledge that will be useful in conservation efforts. They are also working to raise awareness of the critical situation of these snails through exhibits and outreach activities.