Photo: Godman, Frederick Du Cane, 1834-1919 (Public domain) — via Wikimedia Commons
Blackthroat Cichlid (Astatheros macracanthus)
A striking Central American cichlid with a jet-black throat, bold stress bars and the big personality only large cichlids deliver.
Will it live with a Blackthroat Cichlid?
We compare each fish against your blackthroat cichlid on temperament, size, water parameters and swimming zone. Set your tank size and filter the results.
- Banjo Catfish✅ CompatiblePeaceful · 15 cm · Medium care · 20–26 °C (68–79 °F)
- Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 26–26 °C — no size, zone or temperament conflicts.
- Bristlenose Pleco✅ CompatiblePeaceful · 12 cm · Easy care · 23–30 °C (73–86 °F)
- Compatible on the things that matter: shared water near 26–30 °C, workable temperaments, and no predator-and-prey size gap.
- Clown Loach✅ CompatiblePeaceful · 30 cm · Medium care · 25–30 °C (77–86 °F)
- Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 26–30 °C — no size, zone or temperament conflicts.
- Elephant-nose Knifefish✅ CompatiblePeaceful · 35 cm · Hard care · 24–29 °C (75–84 °F)
- Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 26–29 °C — no size, zone or temperament conflicts.
- Marbled Hoplo✅ CompatiblePeaceful · 14 cm · Easy care · 22–28 °C (72–82 °F)
- Aggressive + Peaceful, but with no direct clash here, and their water overlaps around 26–28 °C — no size, zone or temperament conflicts.
- Medusa Pleco✅ CompatiblePeaceful · 12 cm · Medium care · 26–30 °C (79–86 °F)
- Aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Rubber Lip Pleco✅ CompatiblePeaceful · 12 cm · Easy care · 20–26 °C (68–79 °F)
- Aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Sailfin Pleco✅ CompatiblePeaceful · 50 cm · Medium care · 22–28 °C (72–82 °F)
- Aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Snowball Pleco✅ CompatiblePeaceful · 16 cm · Medium care · 24–30 °C (75–86 °F)
- Compatible on the things that matter: shared water near 26–30 °C, workable temperaments, and no predator-and-prey size gap.
- Spotted Rubbernose Pleco✅ CompatiblePeaceful · 12 cm · Medium care · 20–26 °C (68–79 °F)
- Compatible on the things that matter: shared water near 26–26 °C, workable temperaments, and no predator-and-prey size gap.
- Spotted Talking Catfish✅ CompatiblePeaceful · 15 cm · Easy care · 22–26 °C (72–79 °F)
- Compatible on the things that matter: shared water near 26–26 °C, workable temperaments, and no predator-and-prey size gap.
- Yellow-spotted Pleco✅ CompatiblePeaceful · 35 cm · Medium care · 24–27 °C (75–81 °F)
- Aggressive + Peaceful, but with no direct clash here; temperature, pH and hardness ranges all overlap and neither outsizes the other enough to be a threat.
- Black Doras Catfish⚠️ With cautionPeaceful · 60 cm · Hard care · 22–28 °C (72–82 °F)
- Blackthroat Cichlid is small enough to tempt Black Doras Catfish; only risk it in a densely planted setup with hiding spots.
- Your 400 L tank is below the ~500 L this pairing really wants — crowding raises aggression.
- Boesemani Rainbowfish⚠️ With cautionPeaceful · 11 cm · Medium care · 24–28 °C (75–82 °F)
- Expect Blackthroat Cichlid to harass Boesemani Rainbowfish at times; give dense cover and watch them at feeding.
- Boesemani Rainbowfish is small enough to tempt Blackthroat Cichlid; only risk it in a densely planted setup with hiding spots.
- Keep Boesemani Rainbowfish in a shoal of 6+ or it gets stressed and nippy.
- Clown Rasbora⚠️ With cautionPeaceful · 10 cm · Medium care · 23–28 °C (73–82 °F)
- Blackthroat Cichlid is aggressive and may chase or nip the smaller Clown Rasbora — plant heavily and break up sight lines.
- Clown Rasbora is small enough to tempt Blackthroat Cichlid; only risk it in a densely planted setup with hiding spots.
- Keep Clown Rasbora in a shoal of 6+ or it gets stressed and nippy.
- Common Pleco⚠️ With cautionPeaceful · 45 cm · Medium care · 22–28 °C (72–82 °F)
- Watch for Common Pleco picking off any blackthroat cichlid small enough to fit in its mouth.
- Discus⚠️ With cautionPeaceful · 20 cm · Hard care · 28–31 °C (82–88 °F)
- Expect Blackthroat Cichlid to harass Discus at times; give dense cover and watch them at feeding.
- Keep Discus in a shoal of 6+ or it gets stressed and nippy.
- Giant Betta⚠️ With cautionPeaceful · 12 cm · Medium care · 24–28 °C (75–82 °F)
- Blackthroat Cichlid is aggressive and may chase or nip the smaller Giant Betta — plant heavily and break up sight lines.
- Giant Betta is small enough to tempt Blackthroat Cichlid; only risk it in a densely planted setup with hiding spots.
- Giant Danio⚠️ With cautionPeaceful · 10 cm · Easy care · 20–27 °C (68–81 °F)
- Blackthroat Cichlid clearly outsizes Giant Danio and is aggressive; risky unless the tank is big and well-planted.
- Watch for Blackthroat Cichlid picking off any giant danio small enough to fit in its mouth.
- Keep Giant Danio in a shoal of 6+ or it gets stressed and nippy.
- Giant Glass Catfish⚠️ With cautionPeaceful · 15 cm · Medium care · 22–27 °C (72–81 °F)
- Blackthroat Cichlid is aggressive and may chase or nip the smaller Giant Glass Catfish — plant heavily and break up sight lines.
- Giant Kuhli Loach⚠️ With cautionPeaceful · 12 cm · Easy care · 24–30 °C (75–86 °F)
- Giant Kuhli Loach is small enough to tempt Blackthroat Cichlid; only risk it in a densely planted setup with hiding spots.
- Keyhole Cichlid⚠️ With cautionPeaceful · 10 cm · Easy care · 22–28 °C (72–82 °F)
- Expect Blackthroat Cichlid to harass Keyhole Cichlid at times; give dense cover and watch them at feeding.
- Keyhole Cichlid is small enough to tempt Blackthroat Cichlid; only risk it in a densely planted setup with hiding spots.
- Kuhli Loach⚠️ With cautionPeaceful · 10 cm · Easy care · 24–30 °C (75–86 °F)
- Kuhli Loach is small enough to tempt Blackthroat Cichlid; only risk it in a densely planted setup with hiding spots.
- Molly⚠️ With cautionPeaceful · 10 cm · Easy care · 23–28 °C (73–82 °F)
- Blackthroat Cichlid clearly outsizes Molly and is aggressive; risky unless the tank is big and well-planted.
- Blackthroat Cichlid may hunt Molly, fry or shrimplets — safest in a heavily planted tank.
- Moonlight Gourami⚠️ With cautionPeaceful · 15 cm · Easy care · 25–30 °C (77–86 °F)
- Blackthroat Cichlid clearly outsizes Moonlight Gourami and is aggressive; risky unless the tank is big and well-planted.
- Murray River Rainbowfish⚠️ With cautionPeaceful · 11 cm · Easy care · 15–26 °C (59–79 °F)
- Blackthroat Cichlid clearly outsizes Murray River Rainbowfish and is aggressive; risky unless the tank is big and well-planted.
- Watch for Blackthroat Cichlid picking off any murray river rainbowfish small enough to fit in its mouth.
- Keep Murray River Rainbowfish in a shoal of 6+ or it gets stressed and nippy.
- Pearl Gourami⚠️ With cautionPeaceful · 12 cm · Medium care · 24–28 °C (75–82 °F)
- Blackthroat Cichlid is aggressive and may chase or nip the smaller Pearl Gourami — plant heavily and break up sight lines.
- Pearl Gourami is small enough to tempt Blackthroat Cichlid; only risk it in a densely planted setup with hiding spots.
- Striped Eel Loach⚠️ With cautionPeaceful · 12 cm · Medium care · 24–28 °C (75–82 °F)
- Watch for Blackthroat Cichlid picking off any striped eel loach small enough to fit in its mouth.
- Alligator Gar⛔ Not recommendedAggressive · 250 cm · Hard care · 24–28 °C (75–82 °F)
- Blackthroat Cichlid and Alligator Gar are both territorial and at least one is outright aggressive — expect serious fighting.
- Size gap is too large (250 vs 25 cm): Alligator Gar will treat Blackthroat Cichlid as food.
- Your 400 L tank is below the ~3785 L this pairing really wants — crowding raises aggression.
- Clown Knifefish⛔ Not recommendedAggressive · 90 cm · Hard care · 24–28 °C (75–82 °F)
- Two assertive fish, one genuinely aggressive: Blackthroat Cichlid and Clown Knifefish will hold territory and clash.
- Size gap is too large (90 vs 25 cm): Clown Knifefish will treat Blackthroat Cichlid as food.
- Your 400 L tank is below the ~750 L this pairing really wants — crowding raises aggression.
- Fire Eel⛔ Not recommendedSemi-aggressive · 100 cm · Medium care · 24–28 °C (75–82 °F)
- Two assertive fish, one genuinely aggressive: Blackthroat Cichlid and Fire Eel will hold territory and clash.
- Size gap is too large (100 vs 25 cm): Fire Eel will treat Blackthroat Cichlid as food.
- Koi⛔ Not recommendedPeaceful · 90 cm · Medium care · 4–28 °C (39–82 °F)
- Size gap is too large (90 vs 25 cm): Koi will treat Blackthroat Cichlid as food.
- Your 400 L tank is below the ~3800 L this pairing really wants — crowding raises aggression.
- Mekong Giant Catfish⛔ Not recommendedSemi-aggressive · 300 cm · Hard care · 20–28 °C (68–82 °F)
- Blackthroat Cichlid and Mekong Giant Catfish are both territorial and at least one is outright aggressive — expect serious fighting.
- Your 400 L tank is below the ~100000 L this pairing really wants — crowding raises aggression.
- Redtail Catfish⛔ Not recommendedAggressive · 120 cm · Hard care · 24–27 °C (75–81 °F)
- Blackthroat Cichlid and Redtail Catfish are both territorial and at least one is outright aggressive — expect serious fighting.
- Redtail Catfish (120 cm) is big enough to swallow the 25 cm Blackthroat Cichlid whole.
- Your 400 L tank is below the ~5700 L this pairing really wants — crowding raises aggression.
- Spotted Gar⛔ Not recommendedAggressive · 90 cm · Hard care · 18–26 °C (64–79 °F)
- Blackthroat Cichlid and Spotted Gar are both territorial and at least one is outright aggressive — expect serious fighting.
- Spotted Gar (90 cm) is big enough to swallow the 25 cm Blackthroat Cichlid whole.
- Your 400 L tank is below the ~600 L this pairing really wants — crowding raises aggression.
- Wels Catfish⛔ Not recommendedAggressive · 300 cm · Hard care · 15–25 °C (59–77 °F)
- Temperature needs don't overlap (Blackthroat Cichlid 26–30 °C vs Wels Catfish 15–25 °C).
- Blackthroat Cichlid and Wels Catfish are both territorial and at least one is outright aggressive — expect serious fighting.
- Size gap is too large (300 vs 25 cm): Wels Catfish will treat Blackthroat Cichlid as food.
- Your 400 L tank is below the ~20000 L this pairing really wants — crowding raises aggression.
Compatibility is computed from each species' care data — a strong starting point, not a guarantee. Individual temperament varies, so always introduce new fish slowly and watch them.
Blackthroat Cichlid care specs
- Care level
- Hard
- Breeding
- Hard
- Max size
- 25 cm (9.8 in)
- Min tank size
- 400 L (105.7 gal)
- Temperature
- 26–30 °C (79–86 °F)
- pH
- 7–8
- Hardness
- 5–15 dGH
- Lifespan
- 8–12 years
- Diet
- Omnivore
- Swim level
- Middle
- Group size
- Best alone or in a pair
- Family
- Cichlidae
- Origin
- Southern Mexico and northern Central America (Guatemala, Honduras, Belize)
What is a Blackthroat Cichlid?
The Blackthroat Cichlid (Astatheros macracanthus) is the sole member of its genus — a robust, intelligent Central American cichlid that earns its place in the specialist trade through sheer presence rather than beginner-friendly keeping. Adults reach 25 cm (10 in), and the fish’s most striking feature, the jet-black throat patch that deepens dramatically during territorial displays and spawning, gives it both its common name and an unmistakable identity in any large cichlid collection.
Formerly shuffled between Cichlasoma and Amphilophus, the species was placed in its own genus Astatheros in 2008 following phylogenetic revision. It occupies its own niche — too large and too aggressive for community setups, yet rewarding enough for dedicated large-cichlid enthusiasts. Specialist dealers in Europe and North America occasionally import specimens, making it an uncommon but genuine aquarium resident.
Where does the Blackthroat Cichlid come from?
Wild Blackthroat Cichlids are distributed across southern Mexico down through Guatemala, Belize and Honduras, in warm lowland river systems. The natural habitat is turbid and warm, with sandy or muddy substrate, submerged root systems and woody debris that provide territory boundaries for breeding adults.
Water chemistry trends neutral to alkaline (pH 7.0–8.0), consistent with the calcareous geology of much of their range, at moderate hardness (5–15 dGH) and elevated temperatures (26–30 °C / 79–86 °F). This is not a fish that tolerates cool or swinging temperatures; replicating those warm, structured lowland conditions is the foundation of good captive care.
What tank size and setup does a Blackthroat Cichlid need?
The minimum is 400 litres (approximately 105 gallons), and that figure is genuine, not conservative padding. A fully grown 25 cm (10 in) specimen holds a large territory, especially during spawning. Choose a tank that is long and wide rather than tall for horizontal swimming space.
For decor, replicate the natural habitat:
- Substrate: Fine or coarse sand, at least 5–7 cm deep. Blackthroat Cichlids dig pit-nests and rearrange the bottom regularly.
- Structure: Large smooth rocks, flat slate and chunky driftwood to create visual barriers and spawning sites. Sight-breaks are not optional — without them a dominant fish amplifies aggression across the whole tank.
- Planting: Robust rooted plants (Vallisneria, Sagittaria) weighted down, or floating plants (hornwort, water sprite) which are more dig-proof and reduce surface aggression.
- Filtration: Powerful external canister filtration, at least twice the tank volume per hour. Large cichlids are heavy feeders; nitrate buildup is chronic in under-filtered setups.
What water parameters does a Blackthroat Cichlid need?
| Parameter | Range |
|---|---|
| Temperature | 26–30 °C (79–86 °F) |
| pH | 7.0–8.0 |
| Hardness | 5–15 dGH |
| Ammonia / Nitrite | 0 ppm |
| Nitrate | Under 20 ppm with regular water changes |
Stability is more important than hitting a narrow target within those ranges. Weekly water changes of 25–30 % are recommended; the large volume of a 400 L tank buffers swings well, but consistent maintenance is non-negotiable. A reliable heater with a thermostat guard is strongly advised — temperature drops below 24 °C stress the fish and suppress immunity. Elevated hardness within the recommended range is better tolerated than soft, acidic conditions, which sit outside the species’ natural chemistry.
What do Blackthroat Cichlids eat?
Astatheros macracanthus is an omnivore whose wild diet likely includes invertebrates, small fish, plant matter and organic detritus. In captivity:
- Pellet staple: Quality large cichlid pellets as the daily base.
- Protein supplements: Earthworms, frozen krill, mussel and occasional silversides for conditioning.
- Vegetable matter: Blanched courgette, cucumber or spirulina wafers two or three times a week — plant material reduces the risk of Hole-in-the-Head disease linked to nutritionally narrow diets.
Feed once or twice daily in amounts consumed within two to three minutes and remove uneaten food promptly. Avoid feeder fish as a regular diet item; they introduce disease and offer less nutritional value than prepared and frozen foods.
How aggressive is the Blackthroat Cichlid, and what fish can live with it?
The temperament classification is Aggressive — take it literally. Males fight seriously with one another, and conspecific aggression can escalate to fatal injury in enclosed spaces. Even a male-female pair requires a 400 L+ tank with multiple visual barriers and close observation, particularly during spawning when aggression intensifies.
Compatible tank-mates, if attempted, must be robust enough to withstand chasing and large enough not to be eaten. In a suitably oversized tank (600 L+), some keepers have success with large plecos (Pterygoplichthys species) or armoured catfish that occupy the bottom zone. Avoid small fish, small cichlids and peaceful community species. For a full assessment of potential pairings, see Blackthroat Cichlid tank mates.
How do you tell male from female Blackthroat Cichlids apart?
Sexual dimorphism is meaningful but does not always become fully apparent until fish approach maturity at 15–18 cm. Key differences:
- Nuchal hump: Mature males develop a pronounced fatty hump on the forehead. In females this is absent or very modest.
- Size: Males reach the full 25 cm (10 in) maximum; females are typically smaller, often topping out around 18–20 cm (7–8 in).
- Body profile: Ripe females develop a noticeably fuller mid-body and a more rounded ventral profile as they come into breeding condition. The abdomen takes on a slightly pinkish flush near the vent.
- Throat patch: Both sexes show the black throat marking, but it is typically more intense and extensive in dominant males.
Sexing juveniles is unreliable; purchasing a group of six or more and allowing natural pairing is the standard approach for establishing a compatible pair.
How do Blackthroat Cichlids breed?
Breeding difficulty is rated Hard — not because the behaviour is obscure, but because managing aggression safely around a spawning pair is genuinely challenging. When a compatible pair bonds, spawning follows the substrate-spawning pattern of larger Central American cichlids: the pair cleans a flat rock or section of substrate, the female deposits adhesive eggs in rows, and the male fertilises them in passes. Both parents guard the clutch aggressively; a species-only breeding setup is strongly preferable. Eggs hatch in approximately 2–3 days at 28 °C (82 °F), with fry free-swimming after five to seven days. Start fry on baby brine shrimp and finely crushed cichlid flake.
The main challenge is protecting the female from male aggression before and after spawning — have a tank divider ready. Clutch sizes run to several hundred eggs, so plan grow-out space in advance.
What diseases are common in Blackthroat Cichlids?
Large cichlids in inadequately maintained setups are susceptible to several conditions:
- Hole-in-the-Head disease (HITH / Hexamita): Pitting and erosions on the head and lateral line, linked to high nitrates and nutritional deficiencies. Prevention: clean water, regular changes and a varied diet including vegetable matter.
- Ich (white spot): White pinhead spots and flashing, almost always triggered by temperature stress — keep water in the 26–30 °C range and avoid sudden drops.
- Bacterial infections: Secondary infections through fight wounds. Prevent by minimising aggression situations and quarantining any injured fish promptly.
- Bloat / internal parasites: Swollen abdomen, stringy white faeces, loss of appetite — particularly a risk with imported wild-caught specimens.
Health note: this profile covers prevention and recognition only — medication dosing and specific treatment protocols are beyond its scope. For a sick fish, confirm symptoms against a reputable veterinary or fish-health reference before medicating, and use a quarantine tank whenever possible.
How long do Blackthroat Cichlids live?
A well-kept specimen can live 8–12 years — a serious long-term commitment in tank space and consistent husbandry. That lifespan underscores the importance of getting the setup right from the start; retrofitting a larger tank years in is more expensive than starting with adequate space. Keepers who provide stable warm water, a varied diet and a low-stress environment routinely see fish reach or exceed the upper end of the range.
Frequently asked questions
Can I keep two Blackthroat Cichlids together?
Two males in the same tank is strongly inadvisable — they fight relentlessly. A compatible male-female pair is possible in a large tank (400 L+) with sight-breaks, but expect territorial aggression. Most keepers house a single specimen or one proven pair.
What do the stress bars mean on a Blackthroat Cichlid?
Bold dark vertical bars that appear across the body are a stress response — common when the fish is moved, startled, or kept in suboptimal water. Stable water parameters, subdued lighting and hiding spots help the fish settle and the bars fade.
What you need to keep a blackthroat cichlid
The baseline is a heated, filtered 400 L+ tank: a reliable heater to hold 26–30 °C (79–86 °F), a gentle filter that won't batter a blackthroat cichlid in the current, and a tight-fitting lid. Cycle the tank fully before adding any fish.
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