Endangered
Japanese white crucian carp
Carassius cuvieri
Japanese white crucian carp is a minnow in the family Cyprinidae (order Cypriniformes) — Carassius cuvieri, recorded as Endangered.
Appearance
This is a medium-sized fish, growing up to 50 cm, with a broad head and a blunt snout. The scales are large and cycloid in shape, with a complete lateral line. Serration is present on the last ray of the dorsal and anal fins, and the caudal fin is forked.
Range and habitat
Historically, the Japanese white crucian carp was endemic to Lake Biwa, as well as the connected Yodo River system, in Japan. It is a freshwater fish, preferring still or slow moving waters, and occurs at depths up to 20 meters. Typical habitats include lakes, canals, and backwaters.
Pins are Wikidata “endemic to” fields. Orange dots, when present, are GBIF occurrence tiles — survey bias included.
Diet and breeding
An omnivorous species, Japanese white crucian carp feed on a variety foods, among them algae, phytoplankton, macrophytes, and invertebrates, such as insects and crustaceans. Upon reaching 1.8 cm the young fish form schools and move offshore to feed on phytoplankton.
This is reflected in the unique structure of their pharyngeal teeth, that are specialized to feed on phytoplankton. Spawning occurs from April to June, and takes place in areas of aquatic vegetation, among them reed beds. Some individuals will migrate into connected satellite water bodies in order to spawn.
In crisis
It is found in Japan and, as an introduced species, in several other countries in Asia. The wild species in Lake Biwa is listed as an endangered species in the Japanese Red Data Book. Factors in its decline include water pollution, invasive species, and overfishing.
Japanese white crucian carp is Endangered on this catalog because that is the IUCN category stored on Wikidata. Confirm the official criteria and any later count on iucnredlist.org.
Sources
Written for this catalog from the English Wikipedia article on Japanese white crucian carp, Wikidata item Q1090973. Family and order context is original field-guide writing about the group, not a copied assessment of this one species. Wikipedia text is CC BY-SA. Not an IUCN assessment. Counts, when quoted, can change — confirm them on the recovery programme and on iucnredlist.org.



