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Mesonauta festivum

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Is that a Festivum?
by Vinny Kutty

An article on the nomenclature, distribution and husbandry of the cichlid genus Mesonauta.

As far back as I can remember, despite my avowed fondness for the members of the genus Crenicichla, I have always kept either Keyhole cichlids or Festivums. Keyholes and Festivums will always remain near the top of my favorite-list. Perhaps their innocuous and pleasant aquarium behavior reminds me that cichlids do not necessarily have to be terrors in aquaria. They are neither flashy nor easy to breed but they are not difficult to keep and get along famously with most fish and plants you could throw in with them. For all my years of keeping these two fishes, I managed to spawn Keyholes only once and still have not had any luck with Festivums. You see Festivums everywhere so perhaps due to their commonness I was not motivated to give them the conditions they deserve to spawn.

Photograph Nature Organism Grass Rectangle

Festivums have been in the hobby for a long time and you see them illustrated in Innes' old books and articles. They became popular aquarium fish in the 50's and 60's before the invasion of the Rift Lake cichlids, and were then known as Flag cichlid, ("Acara bandeira" or Flag Acara in Brazil) a name they still occasionally go by. Most shops have become hip and prefer to call them just Festivum. In the early days of the hobby, a major source of export was Guyana (British) and we were used to buying "Cichlasoma festivum". Then, when Manaus, Brazil and Iquitos, Peru became larger points of export, we started seeing new "color morphs" of this widely distributed species. "Cichlasoma festivum" was believed to have a very large distribution all the way from Guyanas in the north to Peru in the West, Rio Tocantins in the East and Rio Parana in the South.

As it turns out, in 1991, Kullander and Silfvergrip published a paper explaining that our "Festivum" actually was a number of similar, biologically distinct species deserving once again a genus of their own Mesonauta, possibly in reference to their preference for middle strata of the water column and/or to the position of the dorsal fin origin posterior to the pelvic fin origin which was Gunther's primary diagnostic character.

OK... so what is the fish you have in your tank that you thought was a regular Festivum?

Well, the answer depends on where it is from. Mesonauta insignis (the type species of the genus) is found in the Rio ***** and Rio Orinoco. This is what gets exported out of Manaus and Barcelos, Brazil. Distinguishing character: of the 7 faint vertical bars that these fish exhibit when stressed, 2 and 4 are joined and the scales above the diagonal "flag" bar are reticulated.

M. egregius is found in Rio Meta, Colombia. It is occasionally seen on price lists of fish from Colombia as Festivum. Distinguishing character: bar 3 divided into two.

It is quite certainly M mirificus if it was collected anywhere near Iquitos, or Pebas, Peru. Distinguishing character: divided bar 3 and there are think horizontal lines above the diagonal flag bar.

Southern Peru (Rio Madre de Dios), Bolivia and in Paraguay has the true M. festivus. Unfortunately, this is not a hotbed of aquarium fish export and so, it is unlikely that most of us ever had the real "Festivum" - kinda like the story with Geophagus surinamensis. Distinguishing character: bars 5 and 6 are joined.

Organism Water Fish Adaptation Fin

Rio Xingu and Tocantins have M. acora. Despite increased collection in these two rivers, attention is mainly focused on colorful Loricariids and Pike cichlids. Thus, M. acora is unlikely to be found in your tank. Distinguishing character: divided bar 4

The latest (and most likely not the last) addition to the genus is the fish that was exported into the hobby so often in the 50's and 60's from Guyana, Mesonauta guyanae (Schindler, 1998) described from the Essequibo River in Guyana. There is limited export from Georgetown and so, you are certainly likely to have M. guyanae. I have yet to read any commentary on the authenticity of the status of this new species from other ichthyologists (read: Kullander)

How nice and complicated! Some don't care what species they have and others do. When comfortable, the said bars are not very visible on these fish. You can always put them in a plastic bag and shake them up a bit and wait for the fright patterns to emerge - you can tell pretty easily then. Cruel? Uh-huh. Effective? Certainly. You decide.

So, there are six described species, and Kullander and Silfvergrip believe there are a couple of other undescribed forms out there.

Now that the whatiszit questions are out of the way, how do you raise and breed these species? Heck, don't ask me. I've never bred them. Here's a secret - I've never bred Angels either, of course, I'm talking about wild ones. I can make pike cichlids do the Mambo but no-can-do with Festivums and Angels.

Feeding Mesonauta is very easy - they eat anything that falls in the tank but prefer to eat near or off the surface. All live foods are appreciated and juveniles LOVE fruitflies.

Nature Reptile Organism Terrestrial plant Fish

Members of Mesonauta are found just about everywhere in the Amazon and they are very commonly encountered. They are found near the surface or just below it, always in still waters. Unlike most other cichlid species, Mesonauta, when threatened, do not dive down for cover but swim away while staying near the surface. A characteristic of surface levels of most still bodies of waters in the Amazon is high temperature. I have seen M. insignis in riverside lakes and pools in stagnant water at 90°F and pH 5.4. I had no oxygen meter but would guess that dissolved oxygen was low. The only other cichlid species found with them in that location (Rio Uatuma, Brazil) was juvenile Satanoperca and Acaronia nassa. Fluviphylax pygmaeus, a tiny livebearing fish that mimics surface air bubbles with their eyes were the only non-cichlid fish found in the immediate vicinity.

A few SACSG members (Lee, Wayne, Jim Herman, John Niemans, Nathan Okawa, Wanda Jacobson, Stan Sung and yours truly) went to Peru in 1998. We caught M. mirificus in Rio Momon, near Rio Nanay and in Cocha Vieja, an oxbow lake near the confluence of the two rivers. The water here was very soft (10uS conductivity) and the pH was 7.0. The temperature was a mild 80°F. Here they were found with Apistogramma bitaeniata, Crenicichla lucius, Satanoperca jurupari, Heros appendiculatus, Cichla sp, Aequidens tetramerus, Hypselecara temporalis, and Angels.

Nathan, Wayne and Jim also went to Puerto Ayacucho, Venezuela on the Orinoco couple of years ago and observed M. insignis and many other species while snorkeling. Nathan described their behavior in the wild thusly - they actually school! They hang out in small groups of 6 to 8 adults and when one moves, the rest follow. My observations of the same species in shallow blackwater areas in Brazil are that they form loose congregations with comfortable elbowroom of about a foot between individuals. This behavior is not unlike that displayed by Pterophyllum species. Given this congeniality in the wild, it is unusual to encounter a rogue "Festivum" in aquaria but I recently spoke to Al Knowles and he described just such a scenario. Still, when Mesonauta fight, most aggression is limited to ritual displays of rushing and nudging. Rarely do unpaired harass a conspecific to death or even shred each other's fins.

Most females attain 4-5 inches when full grown but large males sometimes grow to 6 inches. I must mention that I have never seen a 6-inch specimen in the wild.
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  1. Gunther, 1862. "Mesonauta." Catal. Fish. Br. Mus. 4, p. 300
  2. Kullander, S.O. & A.M.C. Silfvergrip. 1991. "Review of the South American cichlid genus Mesonauta Gunther with descriptions of two new species." Revue Suisse Zool.
    98: 407-448.
  3. Schindler, I. 1998. "Mesonauta guyanae spec. nov., a new cichlid fish from the Guyana Shield, South America (Teleostei: Cichlidae)." Zeitschrift Fischkunde, 5: 3-12.
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