Should I buy it?
Marbled Hatchetfish
Carnegiella strigata
Also known as: marbled hatchet
Peaceful top-dwelling tetras with the best gliding-jump behaviour in the hobby. Soft tannin water plus a fully sealed lid is the working setup.
Marbled Hatchetfish tank mates · 60L tank size hub
peaceful · intermediate care
Sources & confidencemedium · partially verified · beginner: caution
Typical care sources — real tanks still vary. Numbers here are a careful starting point. Your tap water, tank size, and habits decide the rest. How we evaluate.
Best for: Soft-water planted community tanks 60L or more with a fully sealed lid and peaceful mid-to-bottom residents below the surface zone.
Avoid if: Your tank lid has any gaps, or you keep surface-active fish that compete for the top zone.
Common mistakeLeaving any gap at the surface edge is how keepers empty a hatchet school overnight. They jump several body lengths through a 2 cm gap, especially after a sudden light change. A tight lid is not optional décor — it is the husbandry.
Top things that go wrong
- Group welfare — not a solo display fish. Plan at least **6** together for normal behaviour; smaller groups often mean stress, colour loss, or nipping depending on species.
- Shrimp & snails. Cherry shrimp and other dwarfs can coexist with peaceful small fish; baby shrimp are food for almost anything that finds them.
What most shops don't tell you
- 1.Myth: hatchetfish are hardy surface community fish for open-top aquascapes and planted shows. Reality: they are confirmed jumpers that need a sealed lid and a real school of six or more — a loose cover loses the group in the first week.
- 2.Confirmed jumper. An open tank or even a loose lid loses the school in the first week.
- 3.Open-top tank or a lid with feeding-hole gaps. Hatchets fly out within days.
- 4.Solo or trio purchase. Hatchets shoal tight in groups of six or more; smaller groups never settle and refuse food.
- 5.Confirmed jumper, peaceful otherwise. A group of six or more in a 60L with a flush lid and surface plants works. Hatchets occupy the top of the water column and ignore mid-water tetras and bottom corys entirely.
About this species
Marbled hatchets are surface-dwelling tetras with a flattened keel-shaped belly and pectoral fins that let them jump several body lengths out of the water. The pattern is brown marbling on a silver flank. South American blackwater origin, soft acidic water, and a tight lid are non-negotiable.
- American Flagfish60L min · same group, comparable tank size
- Golden Wonder Killifish80L min · same fish family
- Pea Puffer40L min · same group, similar adult size
- Clown Killifish20L min · same group, similar adult size
- African freshwater butterflyfish150L min · same fish family
- Ropefish / reed fish200L min · same fish family
- Senegal bichir300L min · same fish family
- Black ghost knifefish500L min · same fish family
- Adolfoi coryalso intermediate peaceful, similar tank size
- Bamboo Shrimpalso intermediate peaceful, similar tank size
- Black ruby barbalso intermediate peaceful, similar tank size
- Brown / hockey-stick pencilfishalso intermediate peaceful, similar tank size
- Cardinal Tetraalso intermediate peaceful, similar tank size
- Celebes Rainbowfishalso intermediate peaceful, similar tank size
No reverse lookups listed yet.
Plan grid
Key limits are above. Here: pH band, swim level, bioload, and activity.
Swim zones
Care snapshot
Quick compare before you buy. Not a score of how “good” the fish is.
- Beginner ease38
- Peacefulness90
- Community fit76
- Small-tank fit100
- Hardiness54
- Energy24
Numbers are deterministic planning indices from Fishori fields — not a scientific score of your individual fish.
Example setups
Starting points only. Run the pair checker for every fish you add.
Rough 90L+ layout: one calm centrepiece, 8–12 small tetras/rasboras, 6–8 corydoras-type bottom fish — verify every name in the pair checker before buying.
Safer directions include: Cardinal Tetra, Rummy Nose Tetra.
Prioritise 6+ of Marbled Hatchetfish in 60L+ with filtration sized for messy feeding — add only mates that already pass pair checks with this species.
Compatibility
Tank mates for Marbled Hatchetfish
Usually safer (engine GOOD): Cardinal Tetra, Rummy Nose Tetra. Conditional (CAUTION — read the pair page before buying): Common Pleco, Otocinclus, Tiger Barb. Avoid (RISKY): Oscar. Every name links to a live pair check — the lists are a shortlist, not a stocking plan.
Usually safer
Open a pair page with this fish as the starting point.
Needs planning
Read the blocking rule on each pair page before experimenting.
Usually avoid
Do-not-stock combinations on conservative hobby rules.
Compare with
Run a real pair check: Marbled Hatchetfish + Cardinal Tetra
Behaviour and temperament
Marbled hatchetfish are peaceful surface schoolers that focus on the film and each other. They stay calmer in soft water with six or more fish. Stress shows as jumping and hiding when the lid is loose or the tank is bright, bare, and noisy below.
What sets them off
- Sudden crowding
- Poor water quality
Fin nipping: Not a habitual fin-nipper; stressed or crowded individuals can still test fins.
Predation: Not a predator toward similarly sized community fish; fry and dwarf shrimp are still fair game for most species.
Territory: Not strongly territorial, but still needs room so its working space does not overlap the next fish.
Planted tanks: excellent — easy plant ideas
In the glass: typical and warning signs
- A school of six or more holds the surface under plants and a tight lid.
- Jumping after a fright is normal — the lid is part of husbandry.
- Repeated lid escapes mean cover failed, not a mystery urge to explore the room.
- A thin group that never feeds at the film usually needs more of its own kind.
- Low listed risk toward similar-sized peaceful fish.
- They lose contests to boisterous midwater traffic rather than starting fin wars.
- Fix the lid before you add more fish to ‘calm’ a jumping school.
- Pull them from tanks dominated by surface-slamming barbs or giant danios.
Fish behaviour can vary between individuals and tank setups. Always observe new fish closely after introduction.
Water, food, and grouping
Hardness
soft
Diet
omnivore
Marbled hatchetfish take fine floating foods and tiny frozen prey at the surface film. Food that sinks past them too fast leaves the school underfed. Offer micro-foods where they hold under a sealed lid, and keep six or more so the group feeds with confidence in softish planted water.
Shrimp & snails
Cherry shrimp and other dwarfs can coexist with peaceful small fish; baby shrimp are food for almost anything that finds them.
Six or more. A tight school is the species' resting behaviour; below six they refuse food and stress.
- A truly sealed lid. Coverslips for every feeding hole and air gap.
- Surface plants (salvinia, frogbit, dwarf water lettuce) to break the surface and reduce panic jumps.
- Soft acidic water (pH 5.5 to 7.0) with tannins from peat or botanicals for true colour.
- A group of six or more from a single source.
- Tank volume meets or exceeds 60L published minimum for adults.
- You can stock at least 6 individuals (group welfare).
- Heater can hold 24–28°C without cooking cooler-water tank mates.
Explore and stocking hubs
Tank-mates hub, matching guides, category peers, and litre stocking lists around this species’ minimum tank.
Plan with tools
Check mates as pairs first, then add this fish in the tank builder for the full stocking.
Filtration & heating
A 60L minimum tank needs a filter rated for at least 240L/hr turnover and a heater to hold 24–28°C reliably.
Plant suggestions
Marbled Hatchetfish does well in planted tanks. Plants compatible with 24–28°C and pH 5.5–7:
Research: partially verified · Confidence: medium · 2 linked source(s). We do not invent citations.
How Fishori evaluates compatibility (same logic as pair and tank tools).
- Seriously Fish. Carnegiella strigata
Primary: species page on Amazon/Rio Negro blackwater origin, jumping behaviour, schooling needs, and feeding (surface foods only).
- Practical Fishkeeping. Marbled Hatchetfish Profile
Secondary: editor coverage of tank setup, surface plant requirement, and the pectoral-fin gliding behaviour.
Evidence notes
- Hatchets feed almost entirely at the surface. Sinking food, flake that drops past the upper third of the tank, and pellet feeds reach mid-water fish before the hatchets see them. Floating micropellets or wet-frozen surface feed are the working diet.
- Wild blackwater origin means tank-bred specimens still want tannin-stained water. A clear tank works for survival, but colour and breeding need peat or alder cones.
Featured compatibility checks
Curated pair pages for Marbled Hatchetfish. Each opens a full verdict — not just a list label.
Common questions about Marbled Hatchetfish
- How big do Marbled Hatchetfish get?
- Marbled Hatchetfish adults reach about 3.5 cm. Shop fish look smaller; stock for the adult length.
- What size tank does Marbled Hatchetfish need?
- 60L is the planning floor for adult swimming space and bioload. A 80L+ tank is the more comfortable long-term footprint. Length and depth matter as much as raw litres for active or territorial fish.
- Are Marbled Hatchetfish aggressive?
- Marbled hatchetfish are peaceful surface schoolers that focus on the film and each other. They stay calmer in soft water with six or more fish. Stress shows as jumping and hiding when the lid is loose or the tank is bright, bare, and noisy below.
- Do Marbled Hatchetfish need to be kept in a group?
- Six or more. A tight school is the species' resting behaviour; below six they refuse food and stress.
- What is the most common mistake with Marbled Hatchetfish?
- Leaving any gap at the surface edge is how keepers empty a hatchet school overnight. They jump several body lengths through a 2 cm gap, especially after a sudden light change. A tight lid is not optional décor — it is the husbandry.
- What fish can live with Marbled Hatchetfish?
- The Marbled Hatchetfish profile lists Cardinal Tetra, Rummy Nose Tetra among its safer pairings (engine-checked GOOD). Common Pleco, Otocinclus, Tiger Barb are conditional (CAUTION): workable only with the specific conditions on each pair page. Avoid Oscar (RISKY). Run the pair checker for your exact water and tank size before stocking.