Chasmistes cujus
The cui-ui is a large sucker fish endemic to Pyramid Lake and, prior to its desiccation in the 20th century, Winnemucca Lake in northwestern Nevada. It feeds primarily on zooplankton and possibly on nanoplankton. The maximum size of male cui-ui is approximately 53 cm (21 in) and 1.6 kg (3.5 lb), while females reach approximately 64 cm (25 in) and 2.7 kg (6.0 lb). A cui-ui typically lives for 40 years but does not reach sexual maturity until at least age eight. The cui-ui is an endangered species, and one of the few surviving members of its genus.

Uncredited · Public Domain · via Wikidata/Commons. May be a photograph of a specimen, or an artist’s reconstruction — an interpretation of a skeleton, since colour and soft tissue are almost never preserved.
On record
Recorded, not inferred- Sits inside
- ChasmistesPBDB
- Diet
- omnivorePBDB, for Cypriniformes
- Life habit
- nektonicPBDB, for Cypriniformes
- Motility
- actively mobilePBDB, for Cypriniformes
- Environment
- freshwaterPBDB, for Cypriniformes
Time the record covers
At most 2.8 million years on record.
The one occurrence read is dated to somewhere between 5.333 Mya and 2.58 Mya, which is a dating window rather than a span.
1 occurrence of Chasmistes cujus on record, most of them in the Pliocene. Bar height is expected occurrences, not a count: each fossil is spread across the span it is dated to, so a tall narrow bar means tight dating and a low wide one means loose.
When
1 occurrences- Pliocene100%
These are dates about fossils, not the animal: the record can only begin after it arose and end before it died out, so either end may reach further. Shares are expected occurrences: a fossil dated to a span is counted partly in each period it straddles. More on what this infers.
Found in
1 formation
Loading coastlines…
The named rock units Chasmistes cujus has been recovered from, largest first. Drawn where the rock is now, not where it formed.
Chasmistes cujus and its relatives
PlioceneWhere Chasmistes cujus and its relatives were recorded in the Pliocene.
Found in the same rock
11 taxa- Anodonta1 site
- Fontelicella (Natricola) melina1 site
- Gila1 site
- Gyraulus1 site
- Helisoma1 site
- Pisidium1 site
- Planorbella1 site
- Valvata1 site
- Valvata humeralis1 site
- Vorticifex1 site
- Vorticifex lasseni1 site
The Paleobiology Database records 1 site for Chasmistes cujus, and this reads all of them. The number is how many of those sites it was catalogued from too.
This is not a list of everything alive at the time. It is only what has come out of the same ground as this animal and been written down.
Entered from
1 referenceEach of the 1 occurrence read was entered from one of these publications, ordered by how many each accounts for. This is not a search for papers mentioning the name. Each entry links to the Paleobiology Database's own record for the work.
Media and terms
Media content1

Picture of Chasmistes cujus
- Source
- Wikidata/Commons
- Credit
- nobody named on the record
- Licence
- Public Domain
- Commercial use
- the licence allows it
No 3D scan was found. Smithsonian Open Access, MorphoSource and Sketchfab were all searched.
The description on this site
- Source
- Wikipedia, “Cui-ui”
- Licence
- CC BY-SA 4.0
This is what the site found, which is not the same as what exists.
Keep going
What may have been alongside itChasmistes through timeFormations of the PlioceneThe world it lived on
Occurrence data from the Paleobiology Database, CC BY 4.0. Cope 1883