Cichlids of the New World
Introduction and Part One - Acaras.
by Dean Hougen
As published in Aqua News March/April 1994
A Publication of the Minnesota Aquarium Society
Aquarticles
Introduction
In this five part series of articles, I intend to cover, by way of introduction, the
cichlids which have evolved in what European explorers 500 years ago termed the "New
World." This includes not only the cichlids of South America, but also those which
have spread northwards to colonize Central America, Mexico, extreme southern Texas and the
Antilles.
In order to cover the New World cichlids in an orderly fashion, I will deal with
closely related genera together. Part one will cover the Cichlasomine group
informally known as the Acaras, Part Two the other Cichlasomines of South America
east of the Andes, Part Three the Cichlasomines of North America and the Pacific
coast of South America, Part Four the Geophagines and finally Part Five will
cover the remaining cichlids including the Crenicichlines, the Cheatobrancines
and the genus Cichia.
Part One - The Acaras
In 1648 the first description and figure of a New World cichlid was published. Written
in Latin by Georg Marcgrave and published posthumously, "Rerum naturalium historiae.
Liber quartos, qsii agit de pivcibus Brasiliae" was the first monograph on south
American fishes. In it, Marcgravius (as he is referred to following the natural sciences
tradition of that time to latinize the scientist's name) describes Acara Brasilienibus
-- the Brazilian Acara.
The use of the name Acara for many of the South American cichlids predates even
Marcgravius, however. The term is Guarani (the language of the Guarani, a native South
American people). It is used to denote many of the generalized cichlids which have what
Leibel (1) describes as an "egg- shaped" body.
I am using it here to cover all of the cichlids in what scientists (e.g. Stiassny,
1991) refer to as 'Cichlasomine group B'. This includes the genera Aequidens,
Bujurquina, Cichlasoma, Cleithracara, Krobia, Laetacara, Nannacara, Tahuantinsuyoa
and a few orphaned species whose genera have been restricted to exclude them, but for
which no new genera have yet been erected.
The Genera
Cichlasoma - Swainson, 1839
Cichlasoma is thought by most aquarists to include fish found from southern
Texas all through Central America and down to Argentina -- fish as diverse as Festivums,
Jack Dempseys, Firemouths, and Severums. Until 1983, this was the case, although
ichthyologists knew that such a collection was incorrect and had to change. Finally, in
1983, Sven Kullander published A Revision of the South American Cichlid Genus Cichlasoma,
in which he restricted the genus to roughly a dozen very similar species including the
type species, many newly described in that work, and a few previously placed in other
genera.
The Cichlasoma species best known to aquarists is Cichlasoma portelegrense
(Formerly Aequidens portelegrensis). All the other members of the restricted
genus are so similar in appearance that they are quite likely to be mistaken for C.
portelegrense by most aquarists. In fact, most "Port Cichlids" sold in the
trade and referred to in aquarium literature are really these other members of Cichlasoma.
More than one hundred species which formerly were included in Cichlasoma have
already been moved to a new or resurrected genera (most of the South American species) or
are still waiting for further revisions to satisfactorily place them (most of the North
American species). These former Cichlasoma species will be covered in the second
and third parts of this series as they fall into what scientists call 'Cichlasomine group
A' - - a group more distantly related to the members of the restricted Cichlasoma
than are species of Aequidens or even Nannacara.
Aequidens - Eigenmann & Bray, 1894
Aequidens too, has been restricted recently by Kullander (1983). Most of the
newly excluded species have been reassigned to other genera, although a few remain in
limbo. Aequidens species greatly resemble Cichlasoma species; the
members of both genera are generalized omnivores, range from four to six inches or so
standard length (excluding the tail fin), and have a similar body shape. They are
scientifically distinguished from Cichlasoma mainly in details of scales and
vertebrae. Aequidens species are also generally more brightly colored and
intricately patterned, often with vermiculations on their cheeks. Like Cichlasoma,
the genus contains roughly a dozen species.
The type species of Aequidens is Ae. Tetramerus. It is extremely
widespread, ranging from the Guianas throughout the length of the Amazon into Peru and
Ecuador. Its basic color is brown, but its chest and throat can be white, yellow, pinkish,
or even red.(2)
Bujurquina - Kullander, 1986
Formerly included in Aequidens, the mouth-brooding Acaras Bujurquina
vittata and B. mariae have been moved to the recently erected genus of which
the type species is the recently described B. moriorum Kullander, 1986. B.
moriorum is also believed to be a mouthbrooder, as wild adults have been caught with
fry in their mouths. Other species of Bujurquina are also known to be
mouthbrooders and it is suspected that all might be. They, and a very few other Acaras,
are believed to be delayed mouthbrooders (see "Breeding" below) which means they
orally brood only the fry, not the eggs.
Bujurquina species are mid-sized Acaras which are conspicuously marked.
Most Bujurquina species are very rare or entirely unknown in the aquarium hobby.
A possible exception to the rule that Acaras are generalists, the recently described B.
oenolaemus Kullander, 1987 may be a specialized molluscivore.
Tahuantinsuyoa Kullander, 1986
Another recently created genus, Tahuantinsuyoa contains two species which
resemble Bujurquina species in color pattern. T. macantzatza, the type
species, is known to be a mouth brooder and T. chipi, recently added by Kullander
(1991), is believed to be. They are relatively small sized (less than four inches standard
length) and their broods are reportedly fairly small (30-60 eggs for T. macantzatza)
as well.
Krobia - Kullander and Nijssen, 1989
Also resembling Bujurquina in some respects (notably the slant to the line
running down the side of the body), Krobia species are found in eastern Amazonia
and the Guianas whereas Tahuantinsuyoa are found in western Amazonia. Krobia
species are also larger, growing up to seven inches or more in standard length.
K. guiansis and K. itanyi were considered Aequidens species
until Krobia was erected. K. guianensis is the "Aequidens
itanyi" of the aquarium hobby, and K. itanyi may never have been found
in the hobby. These two species can easily be distinguished by looking at the line on the
side of the body. In K. itanyi the line stops midway down the side, whereas in K.
guianensis the line continues to the back insertion of the dorsal fin. There are also
at least two undescribed species in this genus.
Ladacara - Kullander, 1986
The dwarf species of Aequidens sensu lato (that is, in the broad sense) have
been moved to the recently erected genus Laetacara. These include such well known
aquarium fish as L. dorsiger and L. curviceps. The type species is L.
flavilabrus, a mostly brownish Acara with purplish "highlights." A very
similar looking species, L. thayeri, is the largest member of the genus, growing
to six inches standard length. L. flavilabrus gets no more than four inches and
the other species are even smaller. Also included in Laetacara are undescribed
species L. sp. "Bucketkopf' (Bumphead), L. sp.
"Orangeflossen" (orange-fin) and probably others.
Laetacara means happy Acara and refers to the "smile" -- snout
markings curving up from the mouth to the eye -- characteristic of the genus.
Cleithracara - Kullander and Nissen, 1989
Another species removed from the Aequidens is the Keyhole cichlid, one of the
hobby's best known Acaras. It has been given a genus of its own, Cleithracara,
that roughly means Keyhole cichlid. ("Lock Acara" would be a closer
translation.) While it grows too large to really be considered a dwarf cichlid (it gets to
five inches standard length), it is quite peaceful and can be housed with dwarf species.
'Aequidens'
Left temporarily without a genus in these revisions are the Blue Acara, 'Aequidens'
pulcher, and its close allies. These include 'Ae' coeruleopunctatus, 'Ae.'
sapayensis and 'Ae.' latiftons, all from northern South America and Panama.
Also orphaned are the Green Terror, 'Ae.' rivulatus, and two or more species,
possibly undescribed, from the Pacific coast drainages of South America -- the only Acaras
found west of the Andes mountains.
Blue Acaras and Green Terrors are staples of today's aquarium hobby. Blue Acaras, along
with 'Ae.' coeruleopunctatus, 'Ae.' latifrons and 'Ae.' sapayensis are
moderate sized Acaras and are not terribly aggressive, whereas Green Terrors get large (at
least eight inches standard length) and are the most aggressive of all Acaras.
Nannacara - Reagan, 1905
Switching gears we come to the other Acara genus which contains dwarf species. It is
Nannacara, which means "small Acara." The type species is N. anomala, a
well known aquarium fish. Recently (1983), Allgayer described the second species of the
genus, N. aureocephalus, but did a rather poor job of it. His description was
based on "overgrown, diseased and poorly preserved aquarium specimens"(3)
and his characters for distinguishing them are doubtful. According to Kullander and Nissen
however, adult males can be distinguished from M. anomala by the spots in
unpaired fins of N. aureocephalus. The species needs to be redescribed,
nonetheless.
True dwarf species, Nannacara males stay under three inches standard length
and females only get half that size. Finally, and for the sake of completeness, is 'Nannacara'
bimaculatum. This fish is little known to the hobby or to science, but I mention it
here to suggest the possibility that there is another genus of dwarf Acaras. It was
described by Eigenmann in 1912 and is in need of further study.
Keeping
Water Conditions
Many of the pools and streams in South America contain "blackwater" -- a
soft, acidic water stained by humic and tannic acids leached from rotting vegetation. If
an aquarist knows anything about South American water, he or she has probably heard of
blackwater. Unfortunately, too many aquarists apparently believe that all bodies of water
in South America contain blackwater; this is certainly not the case. In fact, the mighty
Amazon itself is a "whitewater" river.
The three major water types in South America are "blackwater,"
"whitewater," and "clearwater." Blackwater generally has an extremely
low pH -- in the range of 4 to 5, is lacking in dissolved minerals, and looks black when
viewed from the shore. It is actually quite transparent, looking like tea when held in a
clear container and allowing for good visibility underwater. The Rio Negro ("Black
River") is the prototypical blackwater river. Blackwater is devoid of most microbial,
plant, and insect life, due to its acidic nature and lack of nutrients. Blackwater is
typically found above white, acid sands.
The Amazon River, as mentioned above, is a whitewater river. In sharp contrast to
blackwater, whitewater offers very low visibility as it gets its whitish coloration from
clay silt suspended in the water. This clay silt -- continually eroded from and deposited
on the clay river banks -- makes whitewater rich in nutrients, but there are few submerged
plants as light cannot penetrate the cloudy waters effectively. In still places whitewater
does support an abundant growth of floating plants, however. Whitewater typically has
about a neutral pH.
Clearwater, as its name implies, is the most transparent of water types although it may
have a slight greenish tint due to suspended algae. Its pH may range from 4.5 to nearly 8,
by far the widest range of any South American water type. Like blackwater, clearwater is
generally quite nutrient poor and often is found over a sandy bottom. The Rio Tocantins
and Rio Xingu are clearwater rivers.
There are, of course, bodies of water which readily fit none of the three types
mentioned above. These include coastal rivers and lagoons which are harder and salty and
mud-bottomed swamps.
Acaras are found in all water types and most are able to adapt to a wide range of water
parameters in captivity. Some species, particularly the dwarf species, may be somewhat
sensitive to water parameters, however, and it is probably advisable to keep most species
in conditions resembling those in which they are found in nature, so far as this is
practical. If you are unsure of the native water type(s) for a particular species, a good
rule of thumb to follow is to assume that brightly colored and/or intricately marked
species are blackwater or clearwater species and more drab species are from whitewaters.
This rule works because in whitewater there is little evolutionary pressure towards these
markings as the low visibility prevents them from being used for species recognition or
mate selection. Regardless of the water conditions, Acaras are most often found in calm
waters.
Food
Most Acaras are generalized omnivores. For the aquarist, this means that they do not
need specialized diet for successful keeping. A staple diet of pelleted food or floating
food sticks works just fine for most Acaras. Some of the dwarf species may be too retiring
to come to the surface for floating foods so sinking pellets or flake food may be a better
choice for them. In addition to this dry staple, which most Acaras will take greedily,
quality frozen and live foods are recommended, especially to get the fish into breeding
condition. I recommend frozen bloodworm, chopped earth worms and glass worms for the
larger species and frozen or live brine shrimp and glassworms for the dwarf species. Peas,
whole for the large species and crushed for the smaller ones, are a cheap and easy way to
round out a good Acara diet.
Tank Mates
Acaras, with notable exception of Green Terrors, tend to be relatively peaceful for
cichlids. Their moderate temperament, however, does not extend to any fish small enough to
be considered food. Most Acaras can be successfully mixed with other cichlids of similar
size and temperament, with loracariids (sucker-mouthed catfish), peaceful characins (such
as Tetras or Silver Dollars) too large to be eaten and naked, predatory catfish (such as
Pimelodids) too small to eat the cichlids. If you mix both predatory catfish and characins
together with your Acaras, be sure the catfish cannot eat the characins! Although Loiselle
(4) reports that Nannacara anomala can kill catfish
of the genus Corydoras, my experience has shown that Corys can be successfully
mixed with dwarf Acaras of the genus Laetacara.
As for Green Terrors, follow the suggestions given for the more belligerent
cichlasomines as listed in Part III of this series.
It is not necessary to keep other fish along with your Acaras, but there are a couple
of reasons you might want to: "Target fish," such as comparably sized cichlids
or quick-swimming characins, can help to direct aggression outside of a cichlid pair,
thereby preventing injury to the smaller member of the pair -- generally the female.
"Dither fish," such as a peaceful school of tetras or shoal of Corydoras,
can help shy dwarf species to feel less threatened. This will make them more active in
search of food and more likely to breed.
Breeding
Most Acaras are easily induced to spawn in aquaria. This, and the fact that they are
generally excellent parents, makes them a good choice for first time cichlid breeders.
Most Acaras are biparental substratum spawners with all parental duties shared although
males often spend more time defending the territory and females spend more time caring for
the eggs and fry. They select a somewhat sheltered, smooth, horizontal surface, often a
flat rock, and clean it then deposit a plaque of 100 to several hundred eggs. After two
days or so (depending on temperature and species) the eggs will hatch and the fry will be
cared for attentively by the parents. The fry are generally deposited in pits dug by the
parents in the substrate and moved from one pit to another as the parents see fit. When
the fry become free-swimmng, they are kept in a group by the parents and shooed to the
substrate when danger threatens.
When the fry become free-swimming they should be fed on newly hatched brine shrimp.
Finely crushed flake food can be substituted if no shrimp are available. The parents are
generally exemplary parents and fry can usually be left with the parents until they are
ready to spawn again (which can be as soon as two weeks).
One variant on this breeding strategy, explained most often in the hobby press by Wayne
Leibel, (5) is "movable platform spawning." This
strategy differs from the strategy described above in that the egg-bearing surface is a
leaf or similar object which the parental fish can drag around. Apparently, this allows
wild fish to take eggs to shallow water when danger threatens from below or to deeper
water when the danger is above. The movable platform allows the parents to accommodate
unexpected changes in water levels or flow. It has been demonstrated that many fish once
described as only breeding on rocks will breed on movable platforms if given the chance.(6)
A few Acaras also differ from the outline given above by practicing delayed
mouthbrooding. Under this strategy (also called primitive or larvophilous mouthbrooding),
the parental fish take the eggs into their mouths for protection when the eggs hatch,
rather than keeping the wrigglers in pits in the substrate. This strategy gives a higher
survival rate for newly hatched fry at the cost of lowering the original number of eggs
laid, as all the fry from several hundred eggs could not be accommodated in the Acara
mouth. Acaras which practice delayed mouthbrooding include Ae. diadema and
species of Tahuantinsuyoa and Bujurquina. Many Bujurquina
species are also known to utilize movable platforms.
There are no known immediate mouthbrooders (fish which carry eggs as well as the fry in
their mouths) among Acaras. There are immediate mouthbrooders in the New World Cichlidae
however, but to read about those you will have to wait until Part IV of this series. Part
II, next issue, will cover (most of) the other cichlasomines from South America. These
include some species that many aquarists know of but fail to realize are cichlasoniines.
References
Hougen, Dean F. 1993 ""Aequidens tetromerus 'Red Breast'."
Acara, 1(2): 16-21
Kullander, Sven O. 1983 A Revision of the South American Cichlid Genus Cichlasoma
(Teleostei, Cichlidae). Swedish Museum of Natural History, Stockholm.
Kullander, Sven O. 1984. "Cichlid Fishes from the La Plata Basin. Pait V.
Description of Aequidens plagiozonatus sp. n. (Teleodei, Cichlidae) from the
Paraguay River System." Zoologica Scripta, 13 (2): 155-159
Kullander, Sven O. 1986. Cichlid Fishes of the Amazon River Drainage of Peru.
Swedish Museum of Natural History, Stockholm.
Kullander, Sven O. 1987. "Cichlid Fishes of the La Plata Basin. Part VI.
Description of a New Bujurquina Species from Bolivia. Cybium, 11 (2): 195-205.
Kullander, Sven O. 1991. "Tahuantinsuyoa chipi, a New Species of Cichlid
Fish from the Rio Pachitea Drainage in Peru." Cybium 15 (1): 3- 13.
Kullander, Sven O. and Efrem J. G. Feffeira. 1990. "A New Aequidens Species from
the Rio Trombetm, Brasil, and Redescription of Aequidens pollidus (Telcoaei,
Cichlidae)." Zoologica Scripta, 19 (4): 425-433.
Kullander, Sven O. and Han Nijssen. 1989. The Cichlids of Surinam E. J. Brill,
Leidem The Netherlands.
Leibel, Wayne S. 1985. "Movable Platform Spawning in an Increasing Number of
Neotropical Cichlids." Buntbarsche Bulletin, 107: 2-11.
Leibel, Wayne S. 1992a. "Cichlids of the Americas - Part 3: The 'Port'
Acaras." Aquarium Fish Magazine, 4 (6): 40-48. Leibel, Wayne S. 1992b. "Cichlids
of the Americas - Part 4: The 'True' and 'Blue' Acaras." Aquarium Fish Magazine, 4
(9): 34-46.
Leibel, Wayne S. 1992c. "Cichlids of the Americas - Part 5: The 'Smiling' and
'Mouthbrooding' Acaras." Aquarium Fish Magazine, 4 (10): 44-53.
Leibel, Wayne S. 1992d. "Cichlids of the Americas - Part 6; Oddballs, Misfits, and
Cousins." Aquarium Fish Magazine, 4 (11): 50- 57.
Leibel, Wayne S. 1993. A Fishkeeper's Guide to South American Cichlids. Tetra
Press, Blackburg, VA.
Linke, Horst and Wolfgang Staeck, 1984. Amerikanische Cichliden 1: Kleine
Buntharsche. Tetra Press, Melle, West Germany. American Cichlids I: Dwarf Cichlids
translated by Maureen Pinder. 1989. American Cichlid Association and Tetra Press.
Loiselle, Paul V. 1985. The Cichlid Aquarium. Tetra Press, Melle, West Germany.
Stiassny, Melanie. L. J. 1991. "Phylogenetic Intrarelationships of the Family
Cichlidae: An Overview." In Cichlid Fishes: Behavior, Ecology, and Evolution.
Miles H. A. Keenleyside (ed.). 1-35.
1 Leibel, 1993, p.35
2 Hougen
3 Kullander and Nijssen, p.205
4 Loiselle, p.80
5 E.g. Leibel 1992a, p.46, Leibel 1985
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