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 local population

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 local population

Creatures at Inokashira Park Zoo

Bitterling
Acheilognathus typus

Of all the bitterlings that live only in Japan, this one is said to have the smallest and finest scales. It was named "Bitterling" (peaceful bitterling) because its shiny silver scales resemble coins (zeni). It once lived all over Japan, but was eaten by invasive species such as largemouth bass brought in by humans, causing its numbers to decline. As a result, conservation efforts are being carried out in various regions.

classification	Actinopterygii, Cypriniformes, Cyprinidae
English name	Small Scale Bitterling
distribution	Japan
Residence	Lakes, swamps, waterways, and other areas with slow currents
Size	Total length: 4-12cm
food	Algae on the bottom of the water
Red List	IUCN: VU (Very) Japan: CR (Critically Endangered) Tokyo: EX (Extinct)

Inokashira Park Zoo Exhibition Area

Inokashira Park Zoo and Aquatic Life House

Using shellfish to lay eggs

During the breeding season, Bitterling bitterlings will be seen searching for and observing bivalves. Once they have selected a bivalve, they will extend a thin tube called an ovipositor into it and lay their eggs. This is a common spawning method among bitterling species. Eggs laid inside shellfish are less likely to be eaten by fish, and more offspring can survive.