Home / Fishes / Killifish and livebearers / Checkered pupfish
No federal permit to keepCheckered pupfish
Cualac tessellatus
Fishes › Killifish and livebearers (Cyprinodontiformes) › Cyprinodontidae (Pupfish)
The checkered pupfish (Cualac tessellatus) is a species of pupfish endemic to San Luis Potosí in Mexico where it is restricted to the Río Verde and associated waters, including the Media Luna lake (all part of the Pánuco River basin).
Care at a glance
Species-specific aquarium care
- Tank: At least 24 in long and 12 in front to back for one adult (adults commonly reach about 3.1 in / 8 cm).
- Water: Freshwater.
- Temperature: 82–86°F (range recorded for this species).
- Layout: Lives on or near the bottom: floor space and hiding places matter more than height.
Calculated from this species' own FishBase record: tank size from its typical adult length and swimming zone, water values from its recorded ranges. The group guide below fills in general care.
Care guide
Species care notes
- Tank: a base of at least 24 × 12 in (roughly 14 US gallons); space needed is rated “modest tank”.
- Water: hard, alkaline water, 68–86 °F, pH 7.5–8.5, 45–53 dGH.
- Behaviour: temperament peaceful; a shoaling fish best kept in a group of six or more; not a community fish.
- Difficulty: Moderate (Seriously Fish rating).
Short excerpts from the species profile:
- Setup: “Need not be too complicated so long as there are plenty of broken lines-of-sight.”
- Diet: “Chiefly a micropredator feeding on small aquatic crustaceans, worms, insect larvae and other zooplankton although algae and other plant material is taken as well.”
- Tankmates: “This species is rarely available in the aquarium hobby and all efforts at captive breeding are to be encouraged so ideally it should be maintained alone.”
- Breeding: “Captive reproduction is not difficult if the tank or container is properly arranged and maintained.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
Pupfish
Applies to most species in this group. Habitat: These fish occupy shallow vegetated fresh or saline waters, ranging from Florida marshes to coastal lagoons and the isolated Devils Hole pool. [fg179-flag, fg179-sheep, fg179-fws]. Individual species can differ, so compare with the species numbers above and the linked sources.
Housing & setup
- For a flagfish pair, use at least a 60 × 30 cm footprint; groups need more room.
- Break sightlines with plants or spawning mops to provide cover between territorial males.
- Use sponge filtration when eggs or fry are present.
- Encourage filamentous algae for flagfish grazing.
- Flagfish: pH 6.5–8.5 and 2–20 dGH; establish species and population requirements before choosing fresh or saline conditions.
Climate & lighting
| Water | 64.4–86°F |
Diet
- Algae or an algae-containing prepared food for flagfish.
- Small live or frozen Artemia and Daphnia.
- Small bloodworms and other appropriately sized invertebrate foods.
Social life
- Flagfish males form territories; keep groups only with sufficient cover and space. Species-only maintenance is preferable for breeding.
Health watch
- Aggression injuries under overcrowded conditions; a general aquarium-fish risk.
- Ammonia-associated gill damage in inadequately cycled systems.
- Skin parasites or secondary bacterial infections introduced with new fish.
Understanding the animal
About this animal
About this animal
This species grows to a total length of 8 cm (3.1 in). It is the only known member of its genus.
Quoted from the Wikipedia article “Checkered pupfish” (CC BY-SA 4.0) 174
In the wild
In the wild
From this species’ own FishBase record (habitat, bottom type, water and breeding data), not its family. Good care copies these conditions.1
| Where it lives | Lives in freshwater. Stays near the bottom. An egg laying omnivorous fish which prefers rocky-gravelly substratum with vegetation. Aquarium conditions: pH=7.2, H=12, 28°C water temperature. |
| Water it lives in | Freshwater, 82–86 °F (28–30 °C), pH 7.9, hardness 53 dH. |
| Climate | Tropical climate. |
What this means for care
- Keep water within its wild range, 82–86 °F.
From the sources
From the sources
Quoted from the matching sections of reputable sources for this exact species. Specialist databases are used first; Wikipedia (community-edited, CC BY-SA 4.0) only fills gaps. Other sources are short credited quotes.
| Overview | The checkered pupfish (Cualac tessellatus) is a species of pupfish endemic to San Luis Potosí in Mexico where it is restricted to the Río Verde and associated waters, including the Media Luna lake (all part of the Pánuco River basin). This species grows to a total length of 8 cm. It is the only known member of its genus. — Wikipedia (community-edited) |
| Where it lives | Home ranges Population dynamics Growth parameters Max. ages / sizes Length-weight rel. Length-frequencies Mass conversion Recruitment Abundance Life cycle Reproduction Maturity Maturity/Gills rel. — FishBase |
| Biology | An egg laying omnivorous fish which prefers rocky-gravelly substratum with vegetation. Aquarium conditions: pH=7.2, H=12, 28°C water temperature. Not a seasonal killifish. — FishBase |
Data and studies
The numbers
The numbers
Each bar is what one source reports. Where several sources weigh in, the dashed gold band marks their average.
Adult length
Maximum recorded length. Measured as total length. Fish in home aquariums often stay smaller than wild records.
Water temperature
Range the species tolerates in nature; aim for the middle.
pH
Water hardness
Minimum tank footprint
Seriously Fish recommends a tank base of at least 24 × 12 in (about 14 US gallons).
Sources for this sheet
- FishBase (Froese & Pauly, eds.), version 24.07 Peer-reviewed researchThe global scientific database on fishes, maintained by a consortium of research institutions; every value is referenced.
- Seriously Fish species profiles Experienced keeper or breederLong-running aquarium reference written and peer-checked by experienced fishkeepers and ichthyologists; each profile covers habitat, tank size, water, diet, behaviour and breeding.
- Seriously Fish: Jordanella floridae Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- FishBase: Cyprinodon variegatus Peer-reviewed researchAdded in the 2026 source-checked care-guide review.
- US Fish and Wildlife Service: Inside Devils Hole Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- Merck Veterinary Manual: Disorders and Diseases of Fish Zoo, university or veterinaryAdded in the 2026 source-checked care-guide review.
- Wikipedia (species article) Community referenceFree encyclopedia; useful overviews with their own citations. Intro text is quoted under CC BY-SA 4.0.
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