Home / Fishes / Killifish and livebearers / Sheepshead minnow
No federal permit to keepSheepshead minnow
Cyprinodon variegatus
Fishes › Killifish and livebearers (Cyprinodontiformes) › Cyprinodontidae (Pupfish)
The sheepshead minnow (Cyprinodon variegatus), also known as sheepshead pupfish, is a species of ray-finned fish in the family Cyprinodontidae, the pupfishes.
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 1.2 in / 3 cm; the largest recorded was 3.5 in).
- Water: Freshwater (tolerates brackish).
- Layout: Uses both the bottom and open water: give open swimming space plus cover near the substrate.
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”.
- Behaviour: 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.”
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
It is found in salt marsh and estuary environments and is native to the eastern coasts of North and Central America.
Quoted from the Wikipedia article “Sheepshead minnow” (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 and brackish water and the sea. Uses both the bottom and open water. Occurs usually near vegetation in salt, brackish and fresh water. |
| Water it lives in | Freshwater / brackish water / marine. |
| Climate | Subtropical climate. |
| Behavior to plan for | Breeding: open water/substratum egg scatterers. |
What this means for care
- It tolerates or needs brackish water; check salinity needs before setup.
Native climate (measured)
Native climate (measured)
| Warm-season highs | about 91°F (up to 96°F in the hottest sampled areas) |
| Cool-season lows | about 43°F (down to 26°F in the coldest sampled areas) |
| Average temperature | 55–77°F across sampled records |
| Relative humidity | 70–75% on average (driest month about 68%) |
| Rainfall | about 1192 mm a year, spread fairly evenly |
Measured at 414 wild occurrence records sampled against WorldClim 2.1 climate data (1970–2000 averages). Air conditions in the range are ecological context, not enclosure settings: microhabitats such as burrows, leaf litter or basking rocks can be cooler, warmer or more humid.
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 sheepshead minnow (Cyprinodon variegatus), also known as sheepshead pupfish, is a species of ray-finned fish in the family Cyprinodontidae, the pupfishes. It is found in salt marsh and estuary environments and is native to the eastern coasts of North and Central America. — 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 |
| Behavior | The sheepshead minnow is an omnivore, eating both animal and vegetable matter. Its diet mainly consists of detritus, microalgae, crustacean larvae and other small invertebrates. Males are aggressive and will attack fish larger than itself, slashing its prey with its sharp teeth and devouring it when it is subdued. — Wikipedia (community-edited) |
| Appearance and size | The sheepshead minnow is a deep-bodied fish; its body, exclusive of its tail, is nearly half as deep as it is long. The length of the fish averages 30 mm; it ranges to a maximum of 75 mm. It is laterally compressed with flat sides, an arched back and a small head with a flattened top. — Wikipedia (community-edited) |
| Biology | Adults occur usually near vegetation in salt, brackish and fresh water. They inhabit hypersaline lagoons and connecting channels. Found on muddy bottoms in turbid waters. — 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
Common length to maximum recorded length. Measured as total length. Fish in home aquariums often stay smaller than wild records.
Minimum tank footprint
Seriously Fish recommends a tank base of at least 24 × 12 in (about 14 US gallons).
Veterinary & husbandry research
Veterinary & husbandry research
- Resolving mechanisms of toxicity while pursuing ecotoxicological relevance? Hinton DE et al., Marine pollution bulletin 2005
- Assessing contaminant sensitivity of endangered and threatened aquatic species: part I. Acute toxicity of five chemicals Dwyer FJ et al., Archives of environmental contamination and toxicology 2005
- Rapid genetic and morphologic divergence between captive and wild populations of the endangered Leon Springs pupfish, Cyprinodon bovinus Black AN et al., Molecular ecology 2017
- Limited impact of weathered residues from the Deepwater Horizon oil spill on the gut-microbiome and foraging behavior of sheepshead minnows (Cyprinodon variegatus) Wigren MA et al., Journal of toxicology and environmental health. Part A 2024
Peer-reviewed papers that mention this species alongside captivity, zoos, veterinary care or aquaculture. Some cover several species or mention it only in passing, so check the abstract. See all 7 on PubMed → 170
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.
- PubMed (U.S. National Library of Medicine) Peer-reviewed researchIndex of peer-reviewed veterinary, zoo and husbandry research.
- iNaturalist (captive observations) Community referenceCommunity observation platform run by the California Academy of Sciences and National Geographic; observations marked captive show animals living in homes, zoos and aquariums.
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