Home / Fishes / Tetras, piranhas and pacus / Black morpho tetra
No federal permit to keepBlack morpho tetra
Poecilocharax weitzmani
Fishes › Tetras, piranhas and pacus (Characiformes) › Crenuchidae (Darter tetras)
Poecilocharax weitzmani, the black morpho tetra or black darter tetra, is a species of characid found in South America.
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 1.6 in / 4 cm).
- Water: Freshwater.
- Temperature: 75–82°F (range recorded for this species).
- pH: 5.2–6.5.
- Hardness: 0–5 dGH.
- 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 18 × 12 in (roughly 11 US gallons); space needed is rated “modest tank”.
- Water: soft, acidic water, 70–82 °F, pH 3–6.5, 0–5 dGH.
- 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: “Use a soft, sandy substrate since this species mostly feeds from the bottom.”
- Diet: “A micropredator thought to feed on aquatic insect larvae, crustaceans and worms in nature with perhaps some fish fry taken as well.”
- Tankmates: “Not an efficient competitor despite its predatory nature and should therefore be the focal species of any community.”
- Breeding: “Not often bred in captivity but certainly possible.”
From the Seriously Fish profile for this species, which has the full habitat, maintenance, diet, behaviour and breeding write-up 167
Darter tetras
Applies to most species in this group. Habitat: These South American freshwater fishes include shaded leaf-litter rainforest-stream Poecilocharax and darters from Brazilian and Amazon–Orinoco drainages. [fg180-morpho, fg180-char, fg180-ammo]. Individual species can differ, so compare with the species numbers above and the linked sources.
Housing & setup
- Poecilocharax weitzmani pair or single-male harem: at least a 45 × 30 cm footprint.
- Additional males: at least 30 × 30 cm territory each, with refuges.
- Poecilocharax: soft sand, leaf litter, roots and spawning caves.
- Poecilocharax: dim lighting, gentle filtration and a mature aquarium.
- Poecilocharax: pH 3.0–6.5 and 0–5 dGH; not a family-wide prescription.
Climate & lighting
| Water | 69.8–82.4°F |
Diet
- Poecilocharax: live Daphnia and Artemia.
- Poecilocharax: grindal worms or microworms.
- Poecilocharax: chopped bloodworms; dried foods are often refused.
Social life
- Poecilocharax do not school; males defend territories. Keep more females than males and avoid competing bottom fish.
Health watch
- Wasting after import and food refusal.
- Fin damage from territorial males.
- Water-quality-associated gill or skin disease; a general aquarium-fish risk rather than documented family-specific prevalence.
Understanding the animal
About this animal
About this animal
The fish was first discovered in 1965.
Quoted from the Wikipedia article “Poecilocharax weitzmani” (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. Uses both the bottom and open water. |
| Water it lives in | Freshwater, 75–82 °F (24–28 °C), pH 5.2–6.5, hardness 5 dH. |
| Climate | Tropical climate. |
What this means for care
- Keep water within its wild range, 75–82 °F.
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 70°F (down to 68°F in the coldest sampled areas) |
| Average temperature | 78–82°F across sampled records |
| Relative humidity | 77–85% on average (driest month about 79%) |
| Rainfall | about 2642 mm a year, spread fairly evenly |
Measured at 66 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 | Poecilocharax weitzmani, the black morpho tetra or black darter tetra, is a species of characid found in South America. The fish was first discovered in 1965. — 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 black morpho tetra is a small finned fish. Typical total length is 40 mm per FishBase, or 40–50 mm per SeriouslyFish. The black morpho tetra demonstrates significant sexual dimorphism, with males growing longer and more colorful dorsal and anal fins. — Wikipedia (community-edited) |
| Reproduction | Male takes care of young. — 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.
Water hardness
Minimum tank footprint
Seriously Fish recommends a tank base of at least 18 × 12 in (about 11 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: Poecilocharax weitzmani Experienced keeper or breederAdded in the 2026 source-checked care-guide review.
- FishBase: Characidium fasciatum Peer-reviewed researchAdded in the 2026 source-checked care-guide review.
- FishBase: Ammocryptocharax elegans Peer-reviewed researchAdded 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.
- 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.
