• Source: Neale Monks

    Species: Mesonauta festivus

  • Source: jjphoto.dk

    Species: Mesonauta sp. "amazonas"

  • Source: jjphoto.dk

    Species: Mesonauta mirificus

Festivum Cichlids: South American Cichlids for Community Tanks

03 September 2011

The fish we call Festivums, Mesonauta spp., have enjoyed modest popularity for decades. In most ways they are typical medium-sized South American ciclids, but they have never been as popular as Angels, Discus, or even Severums. Nonetheless the can make excellent aquarium fish, and with care are good additions to spacious community tanks.

Festivums can be a little hard to find but the Fish Search tool at the top left of our front page makes it easy to find out which stores have Mesonauta species in stock. You can also use our Tropical Fish 2 Your Door page to order your fish online!


Festivums are medium-sized cichlids that typically reach adult lengths between 10-12 cm (4-5 inches) though smaller and larger specimens have been reported. In terms of shape they are oval in shape, strongly compressed from side to side, and with a distinctive Roman-nose profile. Like Angelfish they have unusually long pectoral fins.

Body colouration varies with mood from silvery-gold to metallic green, and dark vertical bands may be present. All species exhibit a characteristic oblique stripe that runs from the mouth diagonally upwards through the eye, over the shoulder, and onto the trailing edge of the dorsal fin. A black eyespot is usually visible on the caudal peduncle as well.

There are no reliable difference in colouration between males and females, and sexing Festivums is notoriously difficult. However, as with many other cichlids the males may have longer extensions to their dorsal and anal fins, and males tend to get larger and more Roman-nosed than the females. The best way to sex mature fish is by examining their genital papillae. As with most other cichlids, the male has a longer, more pointed genital papilla compared to the shorter, blunter papilla seen on the female.


Mesonauta species are distributed across a wide part of tropical South America, including the Orinoco and Amazon River basins and the coastal rivers of the Guyanas. Some species are particular to blackwater habitats, but others are more adaptable and may be found in other types of environments as well. They are rarely found far from vegetation though, and typically inhabit quiet, densely planted environments with minimal water current.


Until recently all the Festivums were assumed to be a single species, often simply called Cichlasoma festivum in older books, or Mesonauta festivus in more recent ones. They are most closely related to the Angelfish (Pterophyllum spp.) and Discus (Symphysodon spp.). All of these cichlids have laterally compressed bodies, long pelvic fins, vertical banding, and minimal sexual dimorphism. They are also rather similar in terms of social and breeding behaviour.

While aquarists tend to treat all Festivums as just the one species, six species are currently recognised. While they differ only very slightly in appearance, and the name Mesonauta festivus continues to be used indiscriminately, the six species do have dissimilar distributions, and to a large degree the actual species sold in aquarium shops will depend upon where the specimens were collected.

General Care

Festivums are not difficult cichlids to keep. Given their size they will need a reasonably large aquarium, 180 litres upwards. Depth is rather more important than length, and they should not be kept in tanks with less than 30 cm water depth. They are not especially active fish and do not appreciate strong water currents.

Water chemistry should tend towards the soft and acidic, but this is less of an issue with the generalist Mesonauta species than it is with the blackwater species. For the generalist species, anything between 2-20 degrees dH, pH 6-8 will suit them well, while the blackwater ones should be kept in softer, more acidic conditions between 2-10 degrees dH, pH 5.5-7.0. All the Festivums appreciate temperatures towards the warmer end of the range, from 24-28 degrees Celsius suiting them best. Nonetheless, wild-caught Festivums are quite a bit less sensitive than wild-caught Angels or Discus, and farmed Festivums are very adaptable indeed.

A shady, planted tank suits them well, but being somewhat omnivorous soft aquarium plants may be nibbled if hungry. Sturdy species like Amazon swords, Anubias, Vallisneria and Java ferns are your best options if you want to avoid replacing damaged plants. Bogwood can be used to create a dark, tangled 'flooded forest' look that these cichlids will appreciate.


In the wild Festivums are omnivores with a preference for small invertebrate prey such as mosquito larvae and crustaceans as well occasional small fish. Aquarium specimens are adaptable and readily take flake and pellets, as well as the usual small live and wet-frozen foods.

Social Behaviour & Tankmates

Festivums are gregarious when young but pair off when sexually mature. Like Angelfish and Discus, paired Festivums hold territories extending 30-40 cm from their chosen nesting site. Outside of breeding the adults are very tolerant, and groups of six or more specimens can work very well in large tanks.

As community fish Festivums rate about the same as Angelfish. They are completely peaceful towards fish they do not view as a threat, and work well alongside small tetras, barbs, rasboras etc. The main things are to choose tankmates that are neither nippy (Festivums being too slow moving to avoid trouble) nor so small they might be swallowed whole (Festivums being opportunistic, if clumsy, predators). X-ray Tetras, Cardinal Tetras, Penguin Tetras, Silver Hatchetfish, Harlequin Rasboras and Five-Banded Barbs are examples of fish that would make excellent companions for Festivums. Gouramis also work well alongside them, sharing similar the same need for warm, soft, sluggish water conditions. Corydoras tend to prefer cooler water than Festivums, though Corydoras sterbai and Brochis splendens would both work well.

Because they're rather shy and placid, it's best not to combine Festivums with other cichlids, though South American dwarf cichlids like Apistogramma cacatuoides would work well. Angelfish and Festivums tolerate one another well, but Festivums are perhaps a bit too pushy to make good companions for Discus.


In theory at least, breeding Festivums is very similar to breeding Angelfish, though Festivums tend to be much better parents than the average pair of farmed Angelfish. Pairs deposit several hundred eggs on a flat, vertical surface that they clean thoroughly beforehand. The eggs hatch within 3 days, and the fry become free-swimming 3-4 days later. Newly hatched brine shrimp make the best first food for the fry, and if properly cared for the fry grow rapidly, reaching a length of 2-3 cm within a month and sexual maturity within a year.

Mesonauta acora

This species is apparently restricted to the Tocantins and Xingu River basins in central Brazil. Not much is known about its ecology in the wild, though specimens were collected from shallow, thickly vegetated creeks with sandy substrates where the water was very soft water and had a pH of 5.5. The biggest specimens collected in the wild were only 7 cm long.

Mesonauta acora is not normally traded and little is known about its specific requirements in captivity. However, given its ecology in the wild, a blackwater aquarium with soft, acidic water conditions may well be useful.

Mesonauta egregius

Mesonauta egregius is another rarely-seen species, this time native to the Meta and Vichada River basins in the northeastern corner of South America. Shape and colouration are similar to those of other Mesonauta but this species tends to have irregular vertical bands rather than the clear stripes seen on other species. Wild specimens have been reported up to 8 cm in length.

As is the case with Mesonauta acora, Mesonauta egregius is normally found in shallow water habitats among the plants. Water chemistry is generally very soft and acidic.

Mesonauta festivus

This species has a wide distribution that covers much of the Amazon region of Brazil, Bolivia, Paraguay and Peru. Unlike some of the other Mesonauta species it is found in a variety of shallow water habitats, not just blackwater ones. This likely explains its hardiness and adaptability in captivity. It is a variable species, but often greenish-yellow in colour with only very faint vertical bands. Maximum length is at least 10 cm for females, and over 15 cm for males.

Although Mesonauta festivus is the name normally given to Festivums in the UK trade, it's debatable whether this species is the one that actually appears in dealers' tanks! Some maintain that it is in fact Mesonauta insignis that is more often traded. The two species look extremely similar and identification depends on features such as scale counts and fin ray counts, so telling them apart is nigh-on impossible for aquarists dealing with live specimens.

Mesonauta guyanae

Mesonauta guyanae is another rarely-traded species, this time confined to the Rio Negro in Brazil and the Essequibo River in Guyana. Maximum length is reported to be 10 cm. Little is known about its requirements in captivity.

Mesonauta insignis

As noted above, Mesonauta insignis may well be the species more often traded in the UK than any other Festivum, but because it's so difficult to tell them all apart, it's hard to be sure about this. In any case, Mesonauta insignis is another adaptable species known to occur in a variety of habitats in the Amazon and Orinoco River basins of Brazil, Colombia and Venezuela. Wild specimens are said to reach a maximum length of 20 cm, but that is uncommon in captivity, with adult males usually no more than 15 cm long, and females a bit less.

Mesonauta mirificus

Mesonauta mirificus is a species limited to parts of the Amazon River basin in Peru and Colombia, including tributaries of the Ucayali and Amazon.
Again, this species is rarely traded. From what is know about wild fish, this seems to be one of the more adaptable species, but Mesonauta mirificus is hardly ever traded so little is known about its long-term requirements.