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Author: Hougen Dean (Dean Hougen)
Title: Cichlids of the New World. An Unexpected Acara and Part II - "High-bodied Acaras"

Summary:  Heros, Hypselacara, Hoplarcus, Mesonauta, Pterophyllum, Symphysodon, Uaru, Acaronia, Caquetaia. This part includes such fish as Discus, Angelfish, Parrot Cichlid, Severum, Festivum, Uaru.
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Date first published: May/June 1994
Publication: Aqua News,  Minnesota Aquarium Society
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Dr. Dean F. Hougen,
School of Computer Science,
University of Oklahoma,
200 Felgar Street, Room 144,
OK 73019-6151.
4342 Capilano Road,
North Vancouver.
British Columbia. V7R-4J7

Cichlids of the New World
An Unexpected Acara and Part II -- "High-bodied Acaras"

by Dean Hougen
As published in Aqua News May/June 1994
A Publication of the Minnesota Aquarium Society


An Unexpected Acara

I ended the section on genera in Part I by discussing the little known 'Nannacara' bimaculatum "for the sake of completeness."(1) If I had written Part I a couple of months earlier, then 'N.' bimaculatum would have completed the section on Acaras quite well. However, as it is, my article neglected to include the very recently described 'Nannacara' adoketa. This species was described in an article by Kullander and Prada-Pedreros which was published in December 1993. In this article, the authors assign the fish in question to Nannacara, as the rules of zoological nomenclature (2) require that a newly described species be assigned to a genus, but indicate that assignment of this species to Nannacara should be considered provisional and imply that 'N.'adoketa and 'N.'bimaculatum will be removed to a genus of their own, yet to be erected, when more specimens of the two species become available. Hence, I am referring to them here as 'Nannacara'. The species name, adoketa, means unexpected. It refers to the fact that 'N' adoketa was discovered in the Rio Negro, which is about as far inland as one can get in South America. The species of Nannacara proper are found quite near to the coast and 'N.' bimaculatum is found only slightly inland -- apparently occurring only above the Tumatumari Falls on the Essequibo. Nothing is yet known about the keeping of 'Nannacara' adoketa as an aquarium fish. Hopefully some intrepid dwarf cichlid enthusiast will be able to rectify this situation.

Part II - "High-bodied Acaras"

There is no simple term to refer to the genera I am covering in Part II of this series. This is because they are not considered a monophyletic group. The cichlasomines are divided by Stiassny into two putatively monophyletic groups: "group B" (the Acaras I covered in part one) and "group A" which includes all the other cichlasomines from the Americas.(3) In this part of the series I will cover only those genera from cichlasomine group A which occur in South America east of the Andes. The remaining cichlasomines, which are found along the pacific coast of South America and in North America, will be covered in part three of this series.

The cichlids of the genera described below all have a more or less pronounced lateral compression to their bodies which distinguishes them quite readily from the "egg-shaped" Acaras. In some of the genera below the body is quite circular in profile and in all of these species the height of the body is much greater with respect to its other dimensions than in the Acaras. For this reason, I will use the term 'High-bodied Acaras' to refer to the cichlids covered in this instalment of the series.

Unlike the generalized Acaras covered in part one, these fishes have notable specializations in morphology, diet, and breeding patterns. These specializations serve to set them apart from each other as well as from the Acaras.

The Genera

Heros Heckel 1840

In 1983, Sven Kullander restricted Cichlasoma to a dozen species of Acaras, as mentioned in Part 1. This left a great many species without any proper genus. This was roughly the situation when Paul Loiselle wrote The Cichlid Aquarium in 1985. Because he felt he needed to assign these species to some genus, Loiselle used the genus Heros, erected by Heckel 145 years before, as a catch-all genus (much as Cichlasoma had been used before it) to contain all the loosely related cichlasomines for which no proper generic placement had been made.(4)

Because of Loiselle's book, many aquarists in the last decade have come to regard Heros as the proper generic name for several dozen species of cichlasomines from both North and South America. In fact, however, only one year after The Cichlid Aquarium was published, Dr. Kullander restricted Heros to include only H. severus (widely known in the aquarium hobby as the Green Severum) and its close ally H. appendiculatus (sometimes referred to as the Turquoise Severum). The species of the restricted Heros apparently need further study and it is unclear how many species will be included in this genus when the dust settles. It is clear, however, that Heros sensu Kullander will contain only high-bodied, South American species which greatly resemble the Severum, rather than the wide variety included there by Loiselle.

Hypselacara Kullander 1986

Hypselacara means high-Acua (primarily) and high-head (secondarily), both in reference to the shape of fishes in this genus. The two species of this genus were previously assigned to both Heros and Cichlasoma, and are better known to aquarists as Chocolate Cichlids. This name is used to refer to species of both H. temporalis and H. coryphaenoides. These species can easily be distinguished from one another by the placement of the side spot in relation to the lateral line. In H. temporalis the middle of the spot is clearly below the lateral line, whereas in H. coryphaenoides the spot's center is above the lateral line.

Hoplarchus Kaup 1860

Hoplarchus is a monotypic genus erected to contain a fish described by Heckel in 1840 as Heros psitticus. Hoplarchus psitticus is sometimes referred to as the Falsemouth Cichlid in the aquarium hobby due, apparently, to the markings extending back from the corner of the fish's mouth.(5) The species name means parrot (6), and the other common name of this cichlid is, accordingly, Parrot Cichlid. It has rarely been bred in captivity and is much sought after by many cichlid hobbyists. An early spawning report (Ludlow, 1987) indicated that parental H. psitticus are amazingly peaceful for fish reaching well in excess of a foot in length. Leibel (1993), however, reports that adults may be aggressive to one another.(7)

Mesonauta Gunther 1862

Mesonauta was for many years regarded as a monotypic genus by those who did not simply relegate it to synonym with Cichlasoma or Heros. The single species Mesonauta was said to contain was M. festivus, from which the hobby name Festivum is derived. It turns out this position was wrong on both counts. First, if but a single species of Mesonauta were to be recognised, then that species would properly be M. insignis.(8) Second, according to Kullander and Silfvergrip there are at least seven species of Mesonauta, five of which have been described so far and at least two that remain unnamed.

Like H. psitticus, the species of Mesonauta are primarily greenish in body color and markings. Unlike Hoplarchus and all other known cichlids, species of Mesonauta have a distinctive dark stripe running at an angle up from the mouth, through the eye, and across the body to the soft spines of the dorsal fin. In some species of Mesonauta this stripe continues into the dorsal fin to the filamentous extensions at its back. It is clear from looking at photographs of aquarium Festivums that several species of Mesonauta have been present in the hobby through the decades.(9)

Pterophyllum Heckel 1840

Many beginning aquarists are unaware that Angels are cichlids. While most advanced aquarists are quite aware of this fact, a surprising number remain blissfully unaware that Angels are cichlasomines. If one looks at the species of Pterophyllum next to the species of Mesonauta, however, this kinship should be a bit clearer. In fact, Festivums are more closely related to Angels than they are to perhaps any other genus, and nobody has had a problem including Festivums amongst the cichlasomines.

Looking at it from another perspective, the close relationship of the genus Pterophyllum to Mesonauta and some of the others covered in this article helps to reveal why breaking up the catch-all Cichlasoma was necessary. Very few people familiar with Angels and, say, Nicaraguan Cichlids (C.' (Theraps) nicaraguense) would hesitate to laugh at the idea of including them in the same genus, and yet that idea is hardly less ridiculous than including both Festivums and Nicaraguan Cichlids in Cichlasoma, as had been standard practice for nearly eighty years.

The genus Pterophyllum is in need of further research and possibly revision. In 1986, Kullander recognized three species: Pt. scalare, from which the aquarium stock of Angels is said to originate; Pt. altum, which is occasionally seen imported from the wild; and Pt. leopoldi, which is imported very rarely and then often labeled as Pt. dumerilii. (Kullander writes that Pt. dumerilii may be a junior synonym of Pt. scalare.) Pt. altum has very long dorsal and anal fins stretching vertically away from its body. In Pt. scalare these fins are somewhat shorter and in Pt. leopoldi these fins are shorter still. Kullander writes that "[t]he relatively slender, large-scaled and short-finned Pterophyllum leopoldi bridges the morphological gap between Mesonauta and Pterophyllum. "(10)

Symphysodon Heckel 1840

Another cichlid genus often not recognized as cichlasomine is Symphysodon. To see that Discus are indeed cichlasomine, however, requires only that one be familiar with both them and Severums. The similarities apparent to the casual observer, such as body and head shape and color pattern, between the species of Symphysodon and those of Heros are matched by internal likenesses which demonstrate quite clearly the close relationship of these genera.

The two species of Discus are the True Discus, S. discus (also known as the Heckel Discus after its describer), and S. aequifasciatus (from which most of the aquarium strains are derived). There are a number of supposed subspecies of S. aequifasciatus, but these are highly questionable and I won't bother to consider them here.

Uaru Heckel 1840

Uaru amphiacanthoides is infrequently seen in the hobby, but generally appreciated when it is encountered. Having a base golden-gray-brown color to the body with a darker, roughly triangular blotch covering much of the fish's flank, a couple of similarly dark blotches near the eye and on the caudal peduncle, and perhaps something of a bluish tinge to the checks, U. amphiacanthoides is not a spectacularly colored fish. It is possessed of a subtle beauty, however, which may have as much to do with how it carries itself (slowly, gently, and gracefully), as with its physical appearance. It has been said that U. amphiacanthoides, like Tropheus duboisi, is one of those fish whose juvenile color pattern is more attractive than its adult coloration.(11)

U. amphiacanthoides is often referred to in the hobby simply as "the Uaru," probably due to the unwieldiness of the specific nomen. A decade ago this would have been fine, but today there are at least three known species of Uaru. Very similar to U. amphiacanthoides is an undescribed species, sometimes referred to in this country as the "Big-Blotch Uaru." This name is a bit misleading, however, as the blotch is really no larger on this fish than it is on U. amphiacanthoides, it is simply located up higher on the side so that it touches the lateral line (in U. amphiacanthoides the blotch is clearly below the lateral line) and it is more rectangular in shape. Stawikowskil (2) refers to this fish as the "Orangener Keilfleckbuntbarsch" (Orange Triangle-spot-cichlid, probably in reference to its slightly more orange base coloration) to distinguish it from U. amphiacanthoides which the Germans call the "Keilfleckbuntbarsch."

In 1989, Stawikowski described the second named species in Uaru calling it U. fernandezyepezi after Venezuelan ichthyologist Agustin Fernandez Yepez. Far from having any sort of triangular shaped blotch on its side, U. fernandezyepezi is marked with a dark spot on the caudal peduncle (like the other known Uaru species), a dark, broad, vertical band on the rear third of its body, and lighter, thinner, vertical bands on the front two-thirds of its side. These markings are much more reminiscent of Heros severus, than of U. amphiacanthoides.

Acaronia Myers 1940

This genus and the following one are not believed to be particularly closely related to the preceding ones. In fact, older thought had it that Acaronia was an Acaral (3) and Kullander does not list Acaronia among the cichlasomines at all.(14) However, Stiassny (l5) argues that Acaronia belongs to cichlasomine group A, and I have chosen to follow her lead.

The species of Acaronia do somewhat resemble the fish described above in body shape but even a casual glance at the head of an Acaronia will quickly reveal the distinctness of Acaronia. The large eyes and even larger mouth of Acaronia species mark these fish as low-light predators. Acaronia nassa, the type species of The genus, has long been known as the Basketmouth Cichlid because its mouth is not only large, but highly protrusible allowing it to catch its food by "gape and suck." Loiselle has described this fish as "a Blue Acara trying to be a Leaf Fish." (16) The recently described A. vultuosa is similarly equipped.

Caquetaia Fowler 1945

The species of Caquetaia are often referred to as "False Basketmouths" in the hobby. This term refers, of course, to their similarity in jaw structure to the Acaronia species mentioned above. Caquetaia is not believed to be exceptionally closely related to Acaronia (and no one disputes that they are cichlasomines), so their similar mouths may well be the result of convergent evolution. Regardless of how they came by their mouth structures, however, Caquetaia species are also very efficient gape and suck predators.

The three recognized species of Caquetaia are C. kraussi, C. myersi, and C. spectabilis. All three species have been found in the aquarium hobby, but only C. spectabilis has been available with any regularity.


Water Parameters

Like the Acaras covered in part one, the "High-bodied Acaras" come from all water types. Symphysodon species, for instance, are generally found in black waters, while Pterophyllum scalare is more frequently found in white waters. These fish will adapt to water conditions outside those they encounter in their natural habitats, but natural parameters may be conducive to breeding success.

While some of the Acaras, such as Cichlasoma portelegrense, can be kept and bred in cooler temperatures (65-75 degrees Fahrenheit), the High-bodied Acaras much prefer temperatures in the range of 75-85 degrees F and even higher temperatures are often used to breed them. These species are also quite intolerant of poor tank maintenance, although aquarium strains of such fish as Severums may prove hardier in this regard.

Finally, while Acaras are generally found in calmer waters, the High-bodied Acaras are almost always found in very calm waters. If excessive water circulation is created in the aquarium, some of these fish will be blown around the tank and suffer from exhaustion.

Tank Set-up

The fish discussed in this section are among the small number of cichlids which benefit from the height of many home aquariums. For most cichlids, the bottom is the proper place to stay, while most of the high-bodied cichlasomines prefer the middle to upper reaches of the water. A tall tank (many of the standard tank shapes, like the common 55 gallon design, are tall enough) allow these fishes to occupy the level of the tank they prefer while ignoring the activities taking place in the tank's lower reaches.

High-bodied Acaras are usually found in areas with dense, vertically-oriented cover, such as roots plunging down from above or plants growing up from below. The vertical bars marking many of these fishes (e.g. Heros, Symphysodon, and Pterophyllum species) have evolved to hide them in such cover. Such cover is highly recommended in the home aquarium, along with low lighting, to put these species at ease.

It is reported that, in the wild, species of Mesonauta sometimes flee by jumping into the air (l7) (whereas most cichlids dive for deeper water), so a tightly covered tank is probably a good idea.


The species covered in this part of the series have a number of different specializations with regard to food. Uaru and Heros species are notably herbivorous. Acaronia and Caquetaia species are, in large part, piscivorous. Mesonauta, Symphysodon, and Pterophylium species generally feed near the surface or in mid- water.

All the High-bodied Acaras can be kept on a staple of prepared foods (18), but it is probably wise to keep their natural diets in mind. Heros and Uaru species, then, should be given thoroughly washed Romaine Lettuce or Spinach as dietary supplements, and Acaronia and Caquetaia might benefit from chopped frozen fish. I recommend staying away from commercially available feeder fish (whether they be goldfish, guppies, minnows, or whatever) as these are likely to bring diseases and parasites into the tank in the long run. Unwanted fry from fellow aquarists are a safer bet.

All High-bodied Acaras are likely to benefit from a supplement of frozen blood-worms, though a feeding cone or similar device might be necessary for some of these fishes.

Tank Mates

Most of the High-bodied Acaras are quite peaceful when compared to the other members of cichlasomine group A. The exceptions to this rule are the species of Acaronia and Caquetaia which are reported to be extremely intolerant of conspecifics (19) and which will attempt to eat almost any fish smaller than themselves. The members of the genera Heros, Hoplarchus, and Hypselacara are rougher and grow to a larger size than those in Mesonauta, Pterophyllum, and Symphysodon and one should probably not mix species from these two groups. Uaru amphiacanthoides can probably be successfully mixed with members from either of these groups. I have no experience with the other species of Uaru.

Heros, Hoplarchus, Hypselacara, and Uaru can be mixed with the larger Acaras, very large characins that do not feed on fins or scales, and medium to large catfish of the family Loricariidae. Uara amphiacanthoides may also be housed with many of the larger Geophagines (to be covered in part IV of this series).

Mesonauta, Pterophylium, and Symphysodon can be mixed with the smaller Acaras (e.g. Cleithracara) and true dwarf cichlids, the gentler Geophagines such as Geophagus and Satanoperca, Tetras larger than, say, adult Cardinal Tetras (Paracheirodon areirodi), and catfish of the families Callichthyidae and Loricariidae. Some people have reported problems with sucker-mouthed catfish (Loricariids) attacking the slime-coat on Discus, but this may be either a case of mistaken identity (this behavior would not be surprising for Chinese Algae-eaters, Gyrinocheilus aymonieri) or a result of insufficient food for the catfish.

Species of Acaronia and Caquetaia should not be housed with fish smaller than themselves unless the smaller fish are intended as food for these piscivores. Food fish should, on the other hand, be small enough to be easily swallowed, to avoid the possibility that the consuming fish will choke to death on fish too large to be taken in one gulp. Fish such as Silver Dollars (Melynnis argenteus) or large predatory catfish (e.g. Pimelodids) make good tank mates, as do the larger Acaras.

None of the High-bodied cichlasomines should be housed with highly aggressive cichlids (many of which will be covered in the next instalment of this series). Most of the High-bodied Acaras are easily bullied, and while the species of Acaronia and Caquetaia may put up a good fight, they may well damage their intricate jaws if the fighting becomes too serious.


Like just about everything else about these fish, they show more specializations in their reproduction than do most of the Acaras. All the High-bodied Acaras are substrate spawners, but beyond that differences arise. High-bodied Acaras prefer or will accept vertical surfaces for their eggs, rather than horizontal surfaces. Some (e.g. Pterophylium and Mesonauta) move their newly hatched fry from one vertical surface to another; the fry stay affixed thanks to special glands on their heads.

In Symphysodon species and Uaru amphiacanthoides (and perhaps the other Uaru species), parental slime coat seems to make up the lion's share of food for newly free-swimming fry in the wild. Such feeding has also been observed in other cichlids, including Heros severus. In most species of High-bodied Acaras, newly hatched brine shrimp make an excellent first food, as they do for Discus fry large enough to eat them.

Like the Acaras, the High-bodied Acaras are essentially sexually isomorphic and the parental duties are shared relatively equally with the male perhaps protecting the territory more while the female tends the young more closely.

Several High-bodied Acaras, notably Uaru amphiacanthoides and presumably its congeners, Hoplarchus psitticus, and Hypselacara species have juvenile and/or fright patterns more complex than and quite different from their normal adult coloration.

In Part III, I'll finish covering the cichlasomines, showing that their diversity can be even greater where the inter- and intra-familial competition is lower.

1    Hougen p.6
2    As described in the International Code of Zoological Nomenclature.
3    Stiassny, p.33
4    Loiselle, 1984, had set forth this use of Heros the year before his book was published.
5    Gerritson, P.9.
6    Ibid.
7    p.68.
8    Kullander, 1986, p.206.
9    E.g. Imes, p.448, appears to be M. mirificus; Goldstein, p.209, appears to be M. festivus;     Goldstein pp.216-217, appears to be M. insignis.
10  1986, p.210.
11  Loiselle, 1981, P. 15.
12  1989.
13  E.g, Loiselle, 1980, p.45, Loiselle, 1985, p. 221.
14  1986, p. 48.
15   pp.31-32.
16   1985, pp 221-222.
17   Kullander, 1986, p.204 for M. insignis. Kullander and Silfvergrip, p.428 for M. acora.
18   Leibel reports, however, that wild-caught A. nassa will not take prepared foods from the bottom of the tank. 1987, p. l.
19   Leibel, 1987, p.2 for Acacronia. Loiselle, 198 1, p. 17 for Caquetaia.


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Editor's note: This series of articles were received by Aquarticles having been scanned from printed copies using optical character recognition technology.   Inevitably some errors crept in. We have corrected what we could find, but if anyone notices any more errors (particularly Latin names!), please e-mail Aquarticles.