Nanochromis parilus

Male Nanochromis parilus in an aquarium

Nanochromis parilus is a rheophilic West African dwarf cichlid that has been known to the hobby for many years. They are found in the Congo River in central West Africa where they reside in the rapids of the Lower Congo River. Their bodies are long in relation to their height and large adult males are about 3 1/2 inches in length. Females are about a half-inch shorter but are usually larger around the belly. They are generally tolerant of water conditions in the aquarium and there are reports of successful breeding of this species in waters with a pH above 7.5.

Nanochromis parilus General Information

Nanochromis parilus is an interesting West African dwarf cichlid and is a great first species if you want to try fish from this genus. They are generally undemanding of water conditions and eagerly feed on most foods. They are generally not too aggressive and a mated pair will usually stay together long-term. Also, they are among the most commonly available Nanochromis species. To learn more about the genus, read Nanochromis – a genus of West African Dwarf Cichlids, which contains a lot of information not included here.

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Nanochromis parilus male looking directly at camera showing bright red spots above it's eyes

Historically, there has been a lot of confusion surrounding the name of this fish and it is often mistaken for Nanochromis nudiceps which is the type species for the genus Nanochromis. The two species are identified by looking at the pattern of the caudal fin (tail). In N. parilus the top half of the caudal is always horizontally striped with alternating black, white, red, or yellow stripes. By contrast, N. nudiceps has a light-colored stripe on the top edge of the fin which is possibly accompanied by a second fainter dark line.      

Nanochromis parilus Varieties

There have not been enough collection and distribution surveys made to establish known varieties of N. parilus. However, there seems to be some variation in the rows of spots that are found in some individuals. In the species description, Roberts and Stewart reported collecting mostly males that had clear lower caudal fins but there were a few males that had rows of spots. They state that more sampling is needed but they lean toward them being color variants and not a separate species

Nanochromis parilus is often confused with Nanochromis nudiceps which is very similar in appearance. However, it’s easy to tell the two species apart by looking at their caudal fins. Both sexes of N. nudiceps have a light-colored line along the top edge of the caudal that may have a faint darker band below. N. Parilus have bright alternating stripes of white, yellow, red, or black that cover nearly all of the top half of the caudal. The lower half is generally clear but some males may show rows of colorful dots.

Nanochromis parilus male
The alternating colored stripes in the tail are the diagnostic feature that differentiates N. parilus from N. nudiceps. This fish is male but females also have the same caudal fin markings.

Nanochromis parilus in the wild

N. parilus is found in the Lower Congo River below the Malebo Pool and Livingston Falls which separate the middle and lower sections of the Congo River. In the paper describing Nanochromis parilus (Roberts and Stewart, 1976) multiple collection locations were described and all were in the rapids of the lower Congo River. Through additional collections, it was determined that they are found only in the rapids and not in the quiet waters in the long calm sections of the river between rapids (Schwarzer, Misof, Ifuta, & Schliewen, 2011). They appear to have adapted to life in fast waters.

Water conditions in these areas are quite moderate. They were collected in soft water with pH values of 6.5 – 7.5 and water temperatures ranging from 75° – 83° F. There is very little aquatic vegetation in the river and the substrate is sand or rock.

Nanochromis parilus in the aquarium

Keeping and breeding Nanochromis parilus is the same as for all members of the genus as I’ve described in Aquarium Care and Breeding of Nanochromis. Rather than repeat that information, here are a few comments specific to N. parilus.

Aquarium set-up and conditions – There is nothing unusual about setting up a tank to house N. parilus. They are a rheophilic species that is used to fast current so don’t be afraid of water movement in the tank. However, this is not required. They are not a black-water species so they don’t need unusually soft and very acidic water. Instead, soft water with neutral pH at 75° – 80° F should be fine.

Behavior – Remember, each fish has its own personality and your experience may be completely different than mine! That said, I’ve found N. parilus to be generally peaceful. I’ve kept them in groups and pairs without any serious problems. However, It’s always been in tanks with lots of dense cover.

Breeding Nanochromis parilus

As with most Nanochromis, N. parilus females exhibit greatly swollen bellies as they approach breeding time. Their entire abdominal region becomes more intently colored and they develop a very prominent ovipositor. A female can get so swollen with eggs that it looks like she will burst but don’t worry she’s just getting ready to lay her eggs.

Nanochromis parilus female
This female N. parilus clearly shows the ovipositor usually she will use to lay her eggs. She is quite swollen and her tube is very obvious but she is still at least a few days away from spawning. Note also the distinctive stripes marking the upper portion of her tail.

N. parilus are typical cave spawners and the female lays row after row of eggs on the ceiling of the cave while the male waits nearby, taking his turns fertilizing the newly laid eggs. After egg laying is complete the female generally takes full responsibility for the spawn until the fry become free swimming which is 8 – 10 days after egg laying. At this point, the male will join in and both parents will participate in the care of the young. The young are pretty robust and grow rather quickly. Given good food and water, the pair will be ready to spawn again before long and it’s possible to raise more than one spawn at a time in a well-maintained tank.

Buying Nanochromis parilus

Nanochromis parilus are one of the most commonly available Nanochromis species. Unfortunately, that doesn’t mean that you can always find them for sale. It’s probably rare to find them in a pet store but the specialty dealers on the Internet will often list them on their stock lists. For specific advice on where to look visit our Guide to Where and How to Buy Dwarf Cichlids


Most of the information I provide on this website comes from books and websites. While I don’t provide specific citations, these are the sources for most of my information.
South American Books:
Mergus Cichlid Atlas Volume 1 & Volume 2 by Dr. Uwe Römer
South American Dwarf Cichlids by Rainer Stawikowski, I. Koslowski and V. Bohnet
Die Buntbarsche Amerikas Band 2 Apistogramma & Co. by Ingo Koslowski, Translation by Mike Wise
South American Dwarf Cichlids by Hans J. Mayland & Dieter Bork
American Cichlids I – Dwarf Cichlids by Horst Linke & Dr. Wolfgang Staeck
West African Books:
The Cichlid Fishes of Western Africa by Anton Lamboj
African Cichlids I – Cichlids From West Africa by Horst Linke & Dr. Wolfgang Staeck
Apisto sites – the home page of Tom C – Global authority for identification and classification of apistogrammas – An excellent international forum with expert members who gladly share their knowledge.
Much more information is available in our complete exploration of dwarf cichlid information resources.