Kribensis

Water parameters

Tolerated range for this species. Aim for the middle of each band rather than the extremes.

Tank and habitat

Substrate: any.

Behavior

Plant interaction: plant safe.

Feeding

Omnivore that eats flake food, pellets, frozen bloodworm, frozen brine shrimp, frozen daphnia, and live food. Not picky. Feeds at the bottom and in the midwater column. During breeding, both parents forage heavily to fuel egg production and fry guarding. A varied diet with frozen food 2-3 times weekly keeps coloring vibrant, especially the female's characteristic cherry-red belly. Feed twice daily.

Compatibility

• One of the more manageable dwarf cichlids for community tanks, but still a cichlid. A breeding pair defends a territory roughly 30 cm in radius around their cave and will chase anything that enters it, regardless of species or size.
• Outside of breeding, relatively peaceful. Pairs coexist with mid-water community fish (tetras, rasboras, barbs) without conflict, provided the community fish don't stray near the cave.
• Bottom-dwelling tankmates (corydoras, loaches) get the worst of it during breeding because they wander into the defended territory while foraging. This rarely causes injury but the constant chasing stresses them.
• A pair is the standard way to keep kribs. Single specimens are peaceful but lack the interesting behavior. Two pairs in the same tank need 200 L and two distinct cave sites on opposite ends.

Origin and habitat

Pelvicachromis pulcher, the kribensis or krib, is a small West African cichlid endemic to southern Nigeria and coastal Cameroon, living in shallow, heavily vegetated still and slow waters, with some populations in brackish water near river mouths. Boulenger described it in 1901 as Pelmatochromis pulcher, and the everyday name krib comes from an old synonym, Pelmatochromis kribensis. The genus name refers to the belly and the species name means beautiful, both pointing to the cherry-red to purple belly a breeding female flushes. It is one of the easiest cichlids to spawn and is often the first cichlid a hobbyist breeds. Males grow to around 10 cm, occasionally larger in the wild, while females are smaller and deeper-bodied with the stronger breeding colour. An unusual quirk of the species is that the sex ratio of the fry depends on water pH: around neutral the brood is fairly even, more alkaline water skews it toward males, and more acidic water toward females. The fish form monogamous pairs, and it works far better to let a pair form from a group than to force a male and female together, since a rejected partner can be killed.

Breeding

A cave spawner that breeds easily once a pair has settled. Given a cave, a coconut shell half, an upturned pot, or a wood hollow, the female courts the male by dancing and flashing her red belly near the entrance, then lays adhesive eggs on the cave ceiling for him to fertilise. Reported clutches range widely, from a few dozen up to a few hundred. The female does most of the close tending inside the cave while the male patrols outside, and after the eggs hatch in several days both parents herd the free-swimming fry around the tank as a tight cloud, driving off anything that comes near. The fry take baby brine shrimp and crushed flake at once. Parental care runs a few weeks, and a healthy pair will spawn again on a regular cycle, so kribs are quite prolific.

Common problems

The surprise for community keepers is the switch that flips at spawning: a pair that ignored everyone for months suddenly defends a territory hard once eggs are down, so the tank needs enough open space for other fish to keep their distance. The pH-linked sex ratio trips up people trying to raise balanced groups, since very soft or very hard water produces lopsided broods; nudging pH toward neutral evens things out. Females can occasionally become egg-bound, looking swollen and listless, and a cooler water change sometimes helps them release. Beyond breeding, kribs are hardy and undemanding in stable water, though like other cichlids on a poor diet they can develop hole-in-the-head erosion, which clean water and varied feeding prevent.

Bioload

Further reading

• Biotope aquariums: matching fish to their natural habitat
• Setting up a breeding tank