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 Inokashira Park Zoo
Creatures at Inokashira Park Zoo
Stonewort
Nitella mirabilis var. inokasiraensis
Stonewort
Nitella mirabilis var. inokasiraensis
This aquatic plant, a type of algae called sclerotium, is endemic to Japan and was discovered as a new species in 1957 in Inokashira Pond, adjacent to Inokashira Park Zoo. There are male and female plants, each of which produces beautiful orange or yellow reproductive organs (seed-like structures) during the spring breeding season. Due to factors such as deteriorating water quality and the reclamation of wetlands, it is now only known to grow wild in three locations in Japan.
| classification | Kingdom Plantae, Order Caryophyllales, Family Caryophyllales |
|---|---|
| English name | Inokashira Stonewort |
| distribution | Japan (3 locations in Japan, including Inokashira Pond in Mitaka City) |
| Residence | Bodies of Water in Tamsui |
| Size |
Stock length: 20-30cm
|
| food | - |
| Red List |
IUCN: Not rated
Japan: CR+EN (endangered species) Tokyo: CR+EN (endangered species) |
The revived Stonewort
After its discovery, the species disappeared from Inokashira Pond and was thought to be extinct. However, from 2014 to 2018, the pond was drained and the bottom exposed to sunlight, causing spores in the soil to awaken and germinate for the first time in 59 years. However, due to rising water temperatures in the summer and being eaten by invasive species, the species' growth conditions remain unstable, so Inokashira Park Zoo Aquatic Life House is continuing to investigate the water temperature, light, and other growth conditions.