Kribensis
Pelvicachromis pulcher
Also known as: Krib, Rainbow krib, Rainbow kribensis, Purple cichlid, Rainbow cichlid
Kribensis are one of those dwarf cichlids that pack a ton of personality into a small fish-especially once they pick a cave and start acting like proud homeowners. The female's purple/red belly when she's in breeding mode is the real show-stealer, and the pair will do seriously impressive parent-care if they spawn.
Kribensis are small cichlids featuring vibrant yellow bodies, blue-green markings, and a distinctive dark stripe along their lateral line.
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Quick Facts
Size
11 cm
Temperament
Semi-aggressive
Difficulty
Beginner
Min Tank Size
20 gallons
Lifespan
5-8 years
Origin
West Africa
Diet
Omnivore - quality pellets/flakes plus frozen/live foods (worms, crustaceans, insects); will also graze some plant/algae/detritus
Water Parameters
24-25°C
5-8
5-19 dGH
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Calculate heater sizeCare Notes
- Give kribs a 20-gallon (or bigger) tank with lots of hiding spots-caves are non‑negotiable (coconut hut, flowerpot on its side, rock cave). They chill way more when they can claim a "home."
- They're pretty forgiving on water, but keep it stable: ~75-79°F, pH around 6.5-7.5, and don't let nitrates creep up. Sudden swings stress them out more than slightly "off" numbers.
- Decorate with plants, wood, and broken sightlines; an open bare tank makes them act jumpy and more aggressive. Sand or fine gravel is nice because they love to dig and rearrange.
- Feed a mix: good pellets/flakes as the staple, then frozen foods (brine shrimp, bloodworms, daphnia) a few times a week to bring out color and breeding behavior. Go easy-kribs will beg and then bloat if you overdo it.
- Tankmates: peaceful community fish that stay out of their cave zone work best (tetras, rasboras, Corydoras, peaceful barbs). Avoid fin-nippers and other cave/territory cichlids unless the tank is big with lots of structure.
- If you keep a pair, expect "tiny bulldog" energy when they spawn-everything near the cave gets chased. In a community tank, give them extra caves and space or be ready to move the pair to their own tank.
- Breeding is easy: they'll pick a cave, the female turns super purple, and they'll march fry around like little sheepdogs. If you want babies to survive, feed crushed flakes or baby brine shrimp and keep other fish away from the fry zone.
- Watch for bullying: one fish getting pinned in a corner or hiding nonstop usually means the pair didn't bond or the tank's too open. Also keep an eye out for bloat/constipation-skip feeding for a day and cut back on rich foods if they look swollen.
Compatibility
Good Tankmates
- Fast mid-water schoolers like Congo tetras, black skirt tetras, or larger barbs (stuff that can scoot away when the kribs get spicy during breeding)
- Rainbows (dwarf neon rainbows, boesemani, etc.) - active, confident fish that don't hang around the kribs' cave
- Upper-level fish like hatchetfish - they stay out of the kribs' way and avoid the whole 'cave zone' drama
- Sturdy catfish like Corydoras (in a group) - usually fine in a bigger tank with lots of hiding spots; just expect some chasing if the kribs are guarding eggs
- Bristlenose pleco (Ancistrus) - tough, mostly ignores the kribs, and doesn't freak out if it gets a little 'back off' from the pair
- Chill surface livebearers like platies (not guppy-fancy types) - they're quick and generally stay out of the kribs' territory
Avoid
- Other cave-spawning/territorial cichlids (especially other kribs) - you'll get nonstop turf wars unless the tank is big and broken up a ton
- Slow fish with fancy fins (guppies, bettas, longfin anything) - kribs can be fin-nippy and they'll absolutely bully 'pretty but slow' fish
- Super peaceful bottom fish that can't take a hint (small loaches or timid catfish that keep blundering into the cave area)
- Tiny shrimp and most small fry - kribs treat them like snacks, especially once they're settled in
Where kribs come from (and why it matters)
Kribensis (Pelvicachromis pulcher) come from West Africa—slow-ish rivers and streams with roots, leaf litter, and lots of little hiding spots. That’s the whole vibe you want to copy in the tank: cover, caves, and broken lines of sight.
You’ll see them sold as “kribs,” “purple cichlids,” or just Pelvicachromis. Same fish, same attitude—small, tough, and very into caves.
Setting up their tank
Kribs are beginner-friendly because they’re not fragile, but they do have opinions about their space. Give them structure and they settle in fast. A 20-gallon long works great for a pair; bigger is easier if you want tankmates.
- Tank size: 20 long for a pair; 30+ if you want a calmer community setup
- Filtration: anything steady; they don’t love a washing-machine current
- Substrate: sand is my favorite (they sift and dig), but fine gravel works too
- Decor: at least 2–3 caves (coconut huts, rock caves, clay pots) plus wood/plants to break up sightlines
- Plants: hardy stuff like Java fern, Anubias, Crypts—expect a bit of digging around the base
- Lighting: moderate; floating plants help if they’re acting shy
If you’re only going to do one thing: add multiple caves. Kribs chill out way more when they can “own” a spot.
For water, they’re flexible. Mine have done well in neutral community water. If your tap is rock-hard, they’ll still live fine, but breeding is easier in softer, slightly acidic water.
- Temperature: 24–27°C / 75–81°F
- pH: ~6.5–7.5 is a safe target for most setups
- Hardness: soft to moderately hard; they adapt better than many cichlids
What to feed them
Kribs eat like little pigs and color up nicely on a mixed diet. You don’t need anything fancy—just variety. Feed small portions and watch them during meals, because they can get a little bossy.
- Staple: quality pellets (cichlid or community) and/or good flakes
- Frozen: bloodworms, brine shrimp, daphnia (great for conditioning)
- Live (optional): baby brine shrimp, grindal worms—awesome if you’re trying to breed them
- Veg extras: spirulina flakes, blanched zucchini/peas now and then
If they’re breeding, feed a little more often but keep up with water changes. More food = more waste, and kribs don’t forgive nasty water for long.
Behavior and tankmates (the real story)
Most of the time kribs are calm, curious fish. Then they decide it’s family season and suddenly they’re tiny bouncers guarding a nightclub. The key is planning around that switch.
In a community tank they can work really well, but only if you give them space and hiding spots. Bottom-dwellers that want the same real estate can get pushed around—especially during spawning.
- Good tankmates: mid/upper swimmers like tetras (bigger ones), rainbowfish, danios, Congo tetras, barbs that aren’t fin-nippy
- Usually okay with: peaceful gouramis, larger rasboras, livebearers (watch the fry situation)
- I’d avoid: other cave-spawning cichlids in small tanks, super shy fish, long-finned fish they might harass, and most bottom dwellers in tight setups (cories can get stressed if the kribs are nesting)
If you see a krib pair “patrolling” one corner and chasing anything that enters—assume eggs or fry. Rearrange decor or add a visual barrier if the whole tank is getting bullied.
Breeding tips (they’ll probably do it anyway)
Kribs are one of those fish that make you feel like a breeding genius. Give them a cave and good food and they often handle the rest. The female’s belly gets bright and she’ll start showing off in front of the cave—classic krib flirting.
- Give choices: multiple caves with different entrances (they pick what they like)
- Conditioning: frozen foods for a week or two + frequent small water changes
- If you want more fry: slightly softer water often helps (not mandatory, just helpful)
- Expect parenting: both parents usually guard, and they’ll herd the fry around like sheepdogs
First foods for fry: baby brine shrimp is the cheat code. Crushed flakes and microworms work too, but BBS gets faster growth and better survival in my experience.
If you’re breeding in a community tank, don’t be surprised if the parents raise a smaller batch. The cool part is watching the behavior; the annoying part is the parents trying to evict everyone else from the neighborhood.
Common problems to watch for
Most krib issues aren’t mysterious diseases—they’re usually “tank politics” or stress from the setup. If they’re hiding nonstop or staying washed-out, check for aggressive tankmates, too-bright lighting, or a lack of cover.
- Aggression spikes during breeding: chasing, nipping, cornering tankmates
- Digging and plant uprooting: especially around cave entrances
- Bloat/constipation: often from overfeeding rich foods (easy on bloodworms every day)
- Ich after a temperature swing or new fish: they’re hardy, but stress still gets them
- “Mouthy” injuries: scraped faces from digging under rocks or squeezing into sharp decor
Stability beats perfection. Kribs handle a wide range, but they hate sudden changes—big swings in temp, skipped maintenance, or adding a new bully fish can flip them from confident to stressed fast.
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