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Kribensis (Pelvicachromis pulcher) also called rainbow kribs, is a popular freshwater aquarium fish of the cichlid family native to rivers in Central and West Africa including Nigeria and Cameroon.
This dwarf cichlid species is famous for its color and ease of maintenance. Interestingly, its scientific name is a clear depiction of the fish’s beauty and loosely translates to beautiful belly color.
Most fish that fall in the rainbow kribs family are peaceful bottom-dwelling species that will fit in a 20-gallon tank. The fish prefers tropical conditions with the water temperature between 75°F and 77°F and a ph of 6.5.
Kribensis will live singly and even in a community tank better than most larger cichlid species. However, they may nip fins on slow-moving fish such as angels.
Good kribensis tank mates include any fish of a similar size, especially if they live on different water layers in a fish tank. Also, you can keep them with fast dither fish and a few fast algae eaters.
A few companions I would recommend you try with your kribensis are platies, dwarf gourami, kuhli loach, rummy nose tetras, killifish and swordtails.
Even so, rainbow kribs can be quite erratic and unpredictable meaning they can be the most peaceful fish in your fish tank or outrightly belligerent.
For this reason, keeps your kribensis with companions that pose placid temperament.
Kribs are mostly sold in the aquarium market as kribensis, but they also go by a couple of other names which include common kribs, red kribs, super-red kribs, rainbow cichlid, purple cichlid and rainbow kribs.
As I mentioned above, they are endemic to Africa, precisely Southern Nigeria and coastal areas of Cameroon, where they occur in warm, acidic to neutral, soft water.
Small populations of p.pulsher are also known to occur outside their natural range as far as Hawaii, USA but mostly as a by-product of ornamental fish trade.
In the wild, they inhabit both slow and fast-moving water and mostly found in patches with dense vegetation.
Size and Appearance—How Big Do Kribensis get?
In the wild, kribs can grow to a maximum length of about 4.9 inches with an overall weight of 9.5 grams, but in captivity, they may grow to a slightly smaller size.
Also, females are smaller than males with deeper bodies and growing to a maximum length of 3.2 inches.
Most kribensis breeds have a dark stripe that runs from the caudal fin to the mouth and a pink-red abdomen.
Even so, the intensity of the belly color changes during courtship more in females where it turns cherry-red.
Kribensis have an average lifespan of 6 years when raised in a proper fish tank set up and fed a proper diet from quality food.
What Do You Feed Kribensis?
There is an on-going debate as to whether kribs are omnivores or herbivores, but whichever side they fall, they generally feed on most aquarium fish foods whether frozen, live or flake.
In the wild, the fish depends on a host of sources, from worms, crustaceans, and insects to diatoms, green algae, pieces of higher plants and even blue-green algae.
However, recent research has shown that kribs prefer plant-based sources to meaty foods.
Therefore, to maintain your fish in healthy condition, replicate their wild diet, especially not forgetting to feed them with more algae and plant-rich foods.
Ideally, serve them daily portions of high-quality plants and algae heavy diet supplemented with occasional flake, live or frozen food.
Rememeber the food you use should be sinking pellets type because the fish are bottom-dwelling and rarely come up to the surface to feed. Hikari sinking pellets are a good choice.
When you feed your kribs the occasional live food portions, consider bloodworms, daphnia, and blackworms. Moreover, it is imperative to supplement their diet with treats of shrimp pellets.
In case you choose to feed them frozen food, it is always important to warm the food before placing it in the water.
The best way to do this is by using warm water to defrost the food inside a container. Simply warm the outside of your holder for about 15 minutes.
Moreover, you can switch the normal herbivorous diet most kribs prefer with vegetables such as zucchini and shelled peas every now and then.
That said, note that aquarium kribensis can get quite fussy at times, therefore try out different diets to establish what food type the ones in your tank like.
Besides, this is a somewhat grey area where an omnivorous diet was largely accepted in the past, but the recent trends in favor of a herbivorous diet.
Are Kribensis Aggressive in a Community Tank?
Kribensis are acceptably peaceful fish, though they get quite aggressive when breeding, and are somewhat unpredictable, with some individuals more belligerent than others.
They also like to have their space to themselves hence tend to be more feisty in small aquariums where contact with other fish is frequent.
Therefore, be sure not to keep your kribs in an overstocked or too-small fish tank.
Another useful hack is to place them with species you would find in the same habitat as the kribs or companion them with top and middle dwelling fish and only large, docile bottom fish.
That said, mated kribs are infamous bug eyes homicidal maniacs, so you will want to keep them out of a community tank.
Though not safe either, the only fish that can technically companion a mated pair is a fast swimming, slim bodied dither fish that will easily get away in case the kribs attack.
It is also common for aquarists to maintain kribs with a couple of tetra and danio species in a community tank, but you need to exert caution because small fish occasionally get snacked on.
Here is a complete list of freshwater aquarium fish you may have reasonable success when maintained with kribensis.
- Dwarf cichlids
- Cory cat fish
- Harlequin rasboras
- Tiger barbs
- Kuhli loaches
- Rummy nose tetras
- African butterfly fish
- African red eye tetras
- Yellow tail congo tetras
- Black neon tetras
Breeding kribs is fairly easy compared to some larger cichlids and popular aquarium fish like betta, but they are harder to breed than livebearers.
Kribs are uniquely secretive spawners, which means you will need to find a suitable spot for your fish to lay their eggs.
Good choice of items include coconut shells or buy little cichlid stone caves, thought the fish will still spawn in ideal decorations inside the tank in case you don’t provide them with the shells.
Normally, kribensis lay their eggs in rows on the upper surface of the cave and produce a clutch that ranges in size, usually from 40 to 100 eggs.
Both parents usually guard the eggs for a period of between 21 and 28 days.However, female kribs mostly do a lot of the guarding, herding and feeding.
Also, though kribensis are widely regarded soft water fish, they easily adapt to moderately hard water that is acidic, but also alkaline.
Even so, the ph of the water in your breeding tank has a direct link to the sex of your fry. In that, if you want an even number of male and female fish, you will need to the ph neutral.
A water ph below 7 (acidic) will result in more female fry, whereas a ph above 7 (alkaline) yields more male kribs.
Sexing—What is The Difference Between Male and Female Kribensis?
Usually, male kribs are larger and lack a gold sheen on the dorsal fin, but they have more slimline bodies as opposed to the rounder shape on females.
Female kribensis are mostly brightly colored on the belly with the intensity increasing on spawning fish. They have more rounded fins and bodies as well.
Compare to females, the fin configuration of male kribs include considerably more pointed pelvic, dorsal and anal fins and an elongated, spade-shaped caudal fin.
That said, male and female kribs are believed to form monogamous pairs, although polygyny is not uncommon.
A good size tank for breeding kribs is one that is between 30 and 40 gallons, but a temporary aquarium can be as small as 20 gallons.
The tank should have a good filtration system preferably with a sponge filter to keep newborns from getting sucked up as is the case with more powerful systems.
Plus a sponge filter is easily removable and clean with minimum disturbance for the fish.
Kribensis naturally enjoy tropical tanks with the temperature anywhere from 77°F to 80°F. So, in case you don’t have one already, you may want to buy a heater for your tank to maintain the temperature within the acceptable range.
As mentioned earlier, the aquarium water ph determines the sex ratio of your fry, therefore set it according to your preference.
Then remember to provide spawning caves for your kribs to lay eggs in and a substrate in the form of dark pea gravel or sand.
Conditioning Your Kribs
Typically, the conditioning process should last about 1 to 2 weeks.
The most effective way to condition your kribs is feeding them live food such as daphnia, bloodworms, blackworms, white worms and brine shrimp.
After conditioning the fish for a couple of weeks, the female kribensis should find a secluded place to lay her eggs and then coax the male over by dancing around him while quivering.
The male will then fertilize the eggs, and the mother krib will keep guard while fanning the eggs to keep them clean until they’re hatched.
All the best and enjoy keeping Kribensis