Photograph by Oliver Lucanus.
By Oliver Lucanus
From the January 2003 issue
Dwarf cichlids of the genus Apistogramma are among the most widespread cichlids in the Amazon basin. The genus is perhaps one of the most quickly expanding of all cichlid genera. Every year new species are scientifically described and further new varieties and new species are found. Apistogramma are now often split around groups, species flocks that have many common features within the group.
The A. nijsseni group is described to have the following species that all resemble the basic color patterns and body shape of A. nijsseni. While these groups are just a loosely arranged set of characters to describe similar species, they are often helpful in setting up the aquarium and water parameters for similar species.
A. nijsseni Kullander 1979
A. panduro Römer 1997
A. payaminonis Staeck 1991
A. atahualpa Römer 1997
A. norberti Staeck 1991
A. sp. “Lyretail I”
A. sp. “Lyretail II”
A. sp. “Mouthbrooder”
With two new species to be added by this article:
A. sp. “red crescent/Inka,” the high fin nijsseni
A. sp. “black triangle,” the high fin panduro
All the species in this group have a round and high body shape. Females have a color pattern of spots or horizontal stripes. All of them live in blackwater habitats that run through the rainforests of Peru. Often the streams that these fish are found in are no wider than one meter and no deeper than 15 centimeters (6 inches). The substrate is often covered by leaf litter and has some terrestrial plants around its margins. Other fish common in all of these habitats are some small tetras, pencilfish (Nannostomus), Corydoras, and Crenuchus spilurus. There are few predators in this shallow water except for some knifefish and the wolf tetra (Hoplias sp.) that are present in nearly every habitat in the Amazon. Often these habitats are deep in the forest and far away from the main streams of the rivers and their flood zones that can extend for kilometers into the forest. Because of their distance from the main rivers and their ever-changing habitats these small streams are isolated and change little over the course of the year, which may well be the reason these fish could develop into such varied forms found in only tiny isolated areas. Of course this also makes the fish difficult to collect. Many of these fish have been discovered by aquarists searching small streams that cross roads and logging paths. In the absence of such access it may take hours of trekking through the jungle to find fish like these. This leads us to conclude that there are dozens more species to be found in the countless habitats of this nature found deep in the forest.
The two new Apistogramma are no exception. Their habitats are found nearly a day’s journey apart, but both fish unmistakably belong in the group of A. nijsseni –like fish. Apistogramma sp. “red crescent” was found by the German biologist Rainer Schulte. He has been living in Peru for many years to study poison arrow frogs and his search for frogs has taken him to many places in the Peruvian jungle. With his help, a Japanese group first managed to catch and export this spectacular fish last year. They named the fish A. sp. “Inka.” My expedition later that year yielded more Apistogramma of this new species as well as another Apistogramma species and a new Corydoras found in the same habitat. The habitat itself is typical for any fish from this group. The stream crosses a small logging road in several places and the fish are caught in water often less than 10 centimeters (4 inches) deep. In places where fallen trees have caused deeper pools to form, Corydoras and other Apistogramma species are found. This apisto is no less attractive and more similar to A. regani.
The water parameters in this habitat are: temperature 26°C (78°F), clarity 990 cm, pH 5.4, Fe (iron) 0.50 mg/l, GH 0, conductivity 15 µS, color blackwater, substrate white sand covered with leaf litter. The new Apistogramma is nothing short of spectacular. It has many features in common with A. nijsseni. The red margin around the tail, bright yellow ventral fins, and blue sides are common features of nijsseni. The most outstanding difference in the male is the spectacular dorsal fin that can be taller than the body of the fish, with all of the hard rays of the dorsal extended. Another very different feature to note is the more metallic blue flanks with several bars, not two spots like the typical form of nijsseni. The difference is even more extreme in the females: here the easily recognizable pattern of two spots (a large one on the flank and a smaller spot on the base of the tail) seen in A. nijsseni females is replaced by several vertical bars and a blue shine on the body.
In the aquarium the new species is much similar to A. nijsseni but requires larger tanks. The males require territories of at least 20 gallons each. Breeding females are fierce mothers that can defend large spaces even against much larger fish.
A day’s journey north another new Apistogramma was found. This species has common features with A. panduro but also features the dorsal fin extensions! The new fish has the same black triangle on the base of the tail and some extended rays on the dorsal fin. The black vertical stripes and blue shine on the flanks are also displayed in the males. Females are more similar to those of the new “red crescent/Inka” fish than those of A. panduro. Yet they feature only short vertical bars and a small round spot on their flanks. This variety is not nearly as aggressive as the other hifin Apistogramma and may be kept and bred in tanks as small as 15 gallons.
The new additions to this popular group of fish will bring them back to the most sought-after Apistogramma among hobbyists. With much attention paid to the slender Apistogramma species of the Rio Negro (A. diplotaenia, elizabethae, and mendezi) there has been little attention paid to new dwarf cichlids from Peru of late. Surely these stunning new fish will make them popular once again.
Posted December 6th, 2012. Add a comment
Altolamprologus compressiceps. Photograph by MP. & C. Piednoir.
By Chad Christensen
Altolamprologus calvus and A. compressiceps hail from Africa’s Lake Tanganyika. The genus Altolamprologus is limited to these two species. They belong to the family Cichlidae, which has an astounding number of described species worldwide, with many still undescribed and countless varieties and subspecies.
A Complicated History
A. compressiceps was originally described as Lamprologus compressiceps in 1898 by Boulenger. Originally thought to be only one species, it was observed by Pierre Brichard on a 1975 collecting trip that there were some variations in collected “compressiceps.” In 1977, after placing two fish of equal length in a collecting bucket, Brichard realized that he was dealing with two distinct body shapes. He provided Poll with a sufficient supply of speciments and further analysis revealed several more differences which supported the creation of a second closely related species, calvus, in 1978 by Poll. The Latin word “calvus,” meaning bald, was a suitable species name, because, when compared to compressiceps, the calvus lacked scales on the upper portions of the head.
The genus Lamprologus was revised by J. Colombe and R. Allgayer, though Poll later rejected two of three genera and created and redefined the Lamprologus genus. At that time he also erected the genus Altolamprologus for calvus and compressiceps. Most other Lamprologus species ended up lumped into the grab-bag genus Neolamprologus. Dr. Paul Loiselle notes that both studies focus on superficial characteristics and he, and many others, see little value in adopting the name conventions proposed in these destabilizing nomenclature studies until modern methods can verify their validity.
Genus break up and reclassification is a constant game and has been the cause of more than one stern discussion. Remember the ongoing Cichlasoma reclassifications? All the hobbyist can do is be aware of the proposed changes, accepting them gracefully, and realize that a particular fish by any other name is still a fish…the same fish.
A. calvus and A. compressiceps share the same basic body shape. They have high bodies and are quite laterally compressed, hence the original species designation of compressiceps. This lateral compression greatly enhances the ability to pick invertebrates and other edibles from the tiniest crevice. Also documented in this genus is the ability to rotate the eyeballs to a nearly 90° angle with the normal plane, allowing these fish to slowly scrutinize the crevices where they might encounter their next meal.
The compressed body shape not only enhances the ability to forage, but permits defensive concealment. Fitting into small crevices is advantageous in avoiding predation. When these fish lodge themselves in these small places, they tense their bodies in such a manner that spiny fins and scales lock them into place and it is nearly impossible for a predator to pull them backwards out of their cover. When confronted by an aggressor, a similar defense is often invoked in open water. The fish turns sideways and curls away from the bite of the aggressor, thus providing a less vital, scale-flared flank as a target. This is apparent in the aquarium when an over enthusiastic male bullies a smaller female.
The two species can usually be distinguished from each other with very little scrutiny. A. compressiceps has a noticeably higher neck/back when compared to A. calvus. A. compressiceps also has a more upturned mouth, giving their head a shorter, meaner, more pug-like appearance. Both calvus and compressiceps come in a variety of flavors. The color variety depends on the geographical location from which they were collected.
A. calvus (pictured) features a shorter neck than A. compressiceps. Photograph by MP. & C. Piednoir.
It should be noted that calvus and compressiceps do inhabit the same areas and, to my knowledge, no naturally occurring hybridization has been reported or theorized, though this will occur in the extremely unnatural environment of the aquarium. Some color varieties and geographical varieties of A. calvus include the blacks from Cape Chipimbi, Zambia, and from Zaire (now Congo). Yellows come from various Zambian locations, including Nangu Island, Nkamba Bay, and Chilange Rocks, and whites come from Cape Chaitika, Zambia. Some varieties of A. compressiceps include oranges/golds from Cape Chaitika, Zambia and Kigoma, Tanzania, red-fin varieties from Tanzania, and four gold head varities from Malasa Island, Tanzania, Kalambo, Muzi, Tanzania, and the rarer Mutondwe Island, Zambia, which is the only described compressiceps variety to exhibit blue in the fins.
Altolamprologus species come in a number of different color varieties. Photograph by Mark Smith.
Both species have a maximum size of a little over 6 inches for males and 4 inches for females. One noteworthy exception is the dwarf Altolamprologus—one from Sumba Bay, Zambia, and another from Mbita Island, Zambia. These fish may reach only about 3 inches in adult males with the females smaller still.
The species of Altolamprologus, like many other Tanganyikan species, are slow to sexually mature, and they are also an extremely slow-growing fish. Fry of a captive spawn may only reach 5/8 inch in three month’s time 2 inches in a year, and it may take as long as two to three years for the fish to sexually mature, depending on conditions. With this said, it should be no surprise that there is a large difference in price between small fry, larger fry, young adults, and breeding adults. A faster growth rate will be noticed with high quality, a varied diet, and plenty of water changes.
Keeping Altolamprologus Species
Aquarium requirements for Altolamprologus spp. are not unlike those of other Tanganyikan fishes. The extremely hard, alkaline waters of Lake Tanganyika should be simulated in the aquarium. Some people will have local tap water that will suffice, while people from other areas may require chemical manipulation with additives to bolster the mineral content and pH values. The pH of an aquarium housing Tanganyikan species should always be above 7.5, but preferred pH values are between 7.8 and 8.6. It should be noted that ammonia is far more lethal the higher the pH, so great care should be given to providing exceptional biological filtration and regular water changes must be performed.
While hardness is a less critical parameter than pH, achieving water with a medium hardness value or harder is a reasonable goal. Being as Lake Tanganyika is actually so hard that it precipitates calcium, fusing the bounders of the rocky shoreline together, the hobbyist would be hard pressed to provide water that is too hard. Also, the extra hardness provides protection from pH drift and crashes. One important thing to remember is these species are extremely sensitive to chlorine and chloramines, so a suitable dechloraminator should be used.
Lake Tanganyikan cichlids come from exceedingly hard water and therefore require at least medium-hard water in the aquarium. Photograph by MP. & C. Piednoir.
Water temperatures between 76° and 80°F are the best, with 78° proving to be safe medium. Temperatures above 84° are often fatal. The higher the temperature, the more important it is that the water be saturated with oxygen. As the temperature approaches the 84° mark, the fish can and will suffocate if the water is not 100 percent saturated with oxygen. Tanganyikans tolerate temperatures that are too low better than they do ones that are too high. Aquariums will lose heat through evaporation, so they tend to remain several degrees cooler than the room temperature if no other means of heat are provided (heaters, submersed pumps, etc.). If the aquarium is situated in a room that will remain higher than about 85° for any amount of time, such as a non-air conditioned room or a garage in the summer, action should be taken. One way to aid evaporation and help prevent the tank from overheating is to provide extra water circulation with airstones or have a fan blowing across the surface of the water. Opening up the aquarium hood will aid evaporation, although it’s risky with species with that are known to jump. A. calvus and A. compressiceps are not known to be jumpers, except in possibly extreme cases of interspecies aggression or, of course, when being chased by a net.
Most all types of flake foods are accepted. A varied diet will help keep the fish healthy and condition them for breeding. Meat should be added to the diet—live or frozen brine shrimp, as well as bloodworms, are greedily accepted. Live or frozen baby brine shrimp and crushed flake foods are suitable for fry.
Substrate choices are the usual fare of gravel or sand. Crushed coral is another option which helps to raise and stabilize the water’s pH. If gravel is used, a natural brown or darker color is preferred to give a more natural environment. Sand also makes a wonderfully natural substrate. No matter what substrate is used, it should not be deeper than about one inch because without water circulation, the substrate will harbor anaerobic bacteria. An effort should be made to mix up the substrate after siphoning detritus off its surface during weekly water changes. While plants are not a natural part of these species’ biotope, both live and imitation plants may be employed at the hobbyists’ discretion.
In small aquariums (20 longs or 29-gallon), these fish are best kept in pairs or trios, although many can be grown to sexual maturity together. Once fish begin to breed, male conspecific aggression escalates to the point that all subdominant males must be removed for their own safety. In a fairly large aquarium (75 to 135 gallons), more than one male can sometimes be kept successfully. With any size aquarium, having a variety of caves of rockwork is the key to success. Males are fairly hard on the fames so, room permitting, more than one female should be kept with the male. A 40-gallon breeder or a 55-gallon tank will house a male and several females, as well as the desirable addition of dither and/or target fish.
The importance of having a variety of caves, rockwork, and shells cannot be stressed enough. These fish are shy and skittish. Having more hiding places available will make them feel secure and you will actually see them out and about more than if you had less hiding places. Knowing a safe haven is close by makes them much bolder.
Having plenty of Caves, rock work, and shells will reduce aggression in the aquarium and make the inhabitants bolder. Photograph by Mark Smith.
Spawning Altolamprologus Species
Providing a variety of caves also gives the females a better chance of avoiding unwanted advancements by the males. Again, this is where having more than one female is a help—it divides the male’s aggression between more fish so no one fish is relentlessly harassed. Shells should be provided for the females to spawn in, though they are not required. Females will also spawn in caves, but shells are often used due to the convenience for the hobbyist.
Using an appropriately sized shell is important: If the shell is too small, the female can’t fit into it but it’s too big the female can fit too far into it. If the female gets too far into the shell, she may become stuck and also, the hobbyist doesn’t know when the shell is occupied since the fish enters far enough into the shell that no part of the fish is visible.
Another problem with having too large of a shell has to do with spawning itself. The male may also try to enter the shell, which may not allow the female the much deserved break from aggression. If the male does not enter, and the shell is large enough to allow the female deep access, the male may be unable to fertilize the eggs, since the males often simply release their milt near the shell entrance and both fish fan it in towards the deposited eggs. Even if the eggs do get properly fertilized, there is still the risk that they will perish. The clutch of eggs needs constant circulation of clean, aerated water, which the female usually supplies by fanning the eggs. If the eggs are deposited too far into the shell, well away from the opening, the female may be unable to provide the required circulation, despite her best efforts.
The best size shell is one that the female’s caudal fin is visible when she is nestled as far in the shell as she chooses to go. This lets the male easily fertilize the eggs while she still is, for the most part, out of reach of his aggression. Unlike in a larger shell, she can block the opening with her body to guard the eggs and fry. The clutch is close enough to the shell opening that the female can fan a respectable amount of fresh water across them, and the hobbyist can rest assured that he or she knows where the fish is located at a glance.
That being said, a properly set up aquarium should provide more cover than only shells. Shells will be used for shelter if nothing else is available, but males and females alike prefer a cave of some type for non-breeding shelter. This also makes it easier for the hobbyist to know when spawning has occurred, since a female will only be in the shell if she is guarding a clutch. At least one cave should be provided for each fish and, in addition to that, one shell per female. Males will spawn with any females that are ready, and if enough suitable spawning sites are provided, there will often be more than one female guarding fry at a time. The last reason that shells can be considered the best spawning site is a selfish one for the hobbyist: Shells are an easy vessel from which to gather fry. After females have been in their shell for eight to twelve days, the fry can be harvested for transport to a small grow out tank.
Raising the Fry
When gathering the fry from the shell, care should be taken not to let the fry be out of the water any more than can be helped. One of the easiest ways to remove the fry is to prepare a container with water from the aquarium from which the fry are being removed. A clear specimen container works well for this and has the added benefit that it can be hung on the aquarium, preferably on the inside. Grasp the shell and hold it at or near the water’s surface over the container. Rotate the shell in the proper direction to flush out the water. More than likely, the female will remain in the shell, but this is a minor inconvenience since the fry will flow past her and out into the container. To decrease a mother’s physical stress, however, one should attempt to capture the shell while the female is away. After each flushing the shell should be immediately dunked into the container, allowing the shell to refill with water. Rotate the shell to let the air out if necessary. Again, the shell should be raised to just above the surface and flushed. This can be repeated until no more fry flow from the shell.
At this age, the fry still have the sticky area on their heads which allows them to stick to the cave or shell walls and one will notice as they are flushed out into the container that many of the fry are also stuck to each other in little masses. This also makes fry removal a bit harder, but it is helpful to shake the shell, with some water in it, between dunks to free the fry from the shell wall. One could wait and let the fry develop another four to six days into free-swimming fry, but then the hobbyist runs the risk that the fry will swim out of the shell or be flushed out during a water change—been there, done that. Once removed from the safety of the shell, the miniscule fry can easily fall prey to other aquarium inhabitants, perhaps even to dad. While the fry-eating propensities of parental Altolamprologus spp. have been greatly exaggerated, it should be realized that every fish is different and some fish may graze on their offspring. As a friend once told me, the fish don’t read the books, so experimentation would be the only way to discover each fish’s parental abilities.
There is no doubt that some spawns will be lost before the parents settle down and become better parents, but this is often true for many other species. Most hobbyists will not be willing to risk losing the fry to overly predacious parents and will want to remove the fry before they are free swimming. While I currently follow this line of thinking, I must say that watching a pair of Altolamprologus with a tank full of offspring can be very interesting.
To this regard, I can give an account of a wild-caught pair of A. calvus that I kept many years ago. Fry were allowed to grow to nearly ¾ inch before the parents were removed and no cannibalism was detected. I observed, however, that the movement of the fry on the substrate would elicit an immediate predatory reaction from the adults until the fry was recognized as a son or daughter rather than a tasty little invertebrate hors d’oeuvre, at which time the fry’s life was spared.
If a pair is kept alone, there is the risk of the pair bond breaking down due to over aggression. Again, this is where it is beneficial to have several females to one male. An alternative is to use some type of target fish. Target fish will also double as dither fish, giving the Altolamprologus an added sense of security and keeping them far more active and visible. Species that prefer the upper portions of the water column are preferred since there will be no direct competition for territory. There are many species that would be suitable, including various danios, rainbowfish, and larger varieties of killifish. For the Tanganyikan purist, Lamprichthys tanganicanus killifish would be a good choice. An equally appropriate choice would be a group of Cyprichromis or Paracyprichromis. No matter what species are selected, ensure that they are large enough or quick enough to avoid becoming a meal.
Get Your Own Altolamprologus Tank
Species of the genus Altolamprologus are a real joy in the aquarium and easy to keep. They make a great species tank, but do equally well in a community situation. The unique body shape and interesting behavior make it well worth the effort to acquire and keep them. The only hard part is deciding which one geographical color variety you like the best. Well, okay maybe just two tanks with different varieties. Do I hear three?
Building a fishroom is a great way to expand your hobby. Photograph by Ted Judy.
By Mike Hellweg
If you need a place to put more fish and more tanks, a fishroom may be the answer you’ve been looking for. Experienced fishroom builder, Mike Hellweg, offers a two-part article on constructing and maintaining a fishroom. He notes that there are some essential questions to ask yourself before beginning any work.
Questions to Ask Yourself
• Do you want a number of smaller tanks or a few larger ones?
• Do you want to keep warm-water fish or cool-water fish, or a mixture of both?
• Do you want to keep larger fish, smaller fish, or a mixture of both?
• Will you be utilizing natural light?
• How will you heat and/or cool the room?
• How will you control humidity?
• Are you going to be breeding fish or just keeping display tanks?
• If you’re planning on breeding fish, will you need both breeding tanks and grow-out tanks?
• Do you want to have planted tanks or reef tanks that will need extra electrical service?
• Will the tanks be plumbed together with a central filtration system, or set up individually?
• Will you need space to condition water before use?
Finally, it’s a good idea to make as few changes as possible to your home if you only plan to be there for a few years. While it may be a benefit to sell the house with a well constructed hobby room in the basement, having a humid, dank, moldy, and unappealing jury-rigged room in the house will definitely not be a selling point. The man cave is not supposed to be an actual cave! It may seem strange to us as hobbyists, but some people actually see a room full of fish tanks as a negative.
By Rhonda Wilson
For the 60th anniversary issue of TFH, I thought it would be fun to do a list of my top aquatic plants. Of course, I had to decide what sort of top list it would be. In the end, after considering various choices, I decided to include all the options. I chose a mix of plants, some because of their ease of growth, some from their popularity among aquarists now and over time, and some of the ones most likely to be found in the shops. I thought I would do a top-10 list but decided that I had 15 plants I wanted to include, and since it’s all kind of an arbitrary list, that’s what I ended up with. For space considerations, I could only list the top 10 in the magazine, but here are my remaining five favorite aquarium plants.
11. Java Fern
Java fern. Photograph by Mark Smith.
An easy plant to grow for most aquarists and a general all-around favorite, Java fern can tolerate a good range of water conditions and lighting levels. I did have some trouble with them in the water in Phoenix, but they did well with additional CO2. I know most people can grow it with ease in most tap water. Since I recently moved, I’ll be trying it again in my new water. There are several different, very attractive varieties of this fern that can often be found in good pet stores along with the original type of fern. Java fern is particularly well suited to be tied to wood in the aquarium.
12. Cryptocoryne wendtii
Cryptocoryne wendtii. Photograph by Rhonda Wilson.
Cryptocoryne wendtii is a wonderful crypt that comes in a variety of colors and is often available as a potted plant in chain and locally owned aquarium stores. The plants are medium in height and can be used as taller plants in very small tanks and midground ones in moderately sized aquariums. Cryptocoryne can be slow growing but over time easily cover and take over an entire aquarium, with little plants spreading under the substrate. It is also easily propagated from cuttings.
13. Rotala rotundifolia
Rotala rotundifolia. Photograph by Bryce Millar.
Rotala rotundifolia is of the few red plants that will grow under less-than-ideal conditions. The color can range from yellow to pink to peach to red depending on the conditions and lighting it’s grown under. Rotala seems to be happy in a range of conditions and will even tolerate moderate lighting. It does much better with higher light levels and generally gets more red in the leaves under better conditions and lighting. Under optimal conditions, it will send branches across the ground to spread the plant.
14. Guppy Grass (Najas spp.)
Guppy grass. Photograph by Rhonda Wilson.
Guppy grass (Najas spp.) is a long-time aquarium favorite, though it’s not usually found in the stores but is traded regularly at most aquarium clubs. It grows quite rapidly in most conditions and makes for a great plant for hiding fry, which is why it became popular among guppy breeders, hence the name “guppy grass.” The major issue with guppy grass in a mixed planted aquarium is that it grows very rapidly and breaks apart quite easily. Each little node is quite happy to start making a new plant, so it’s very easy to end up with these in places in the aquarium where they’re not really wanted.
15. Bacopa monnieri
Bacopa monnieri. Photograph by Rhonda Wilson.
Bacopa monnieri is a stemmed plant that is very interesting in its structure, with a strong, thick stem and leaf. It looks like a type of succulent. Bacopa not only grows well in the aquarium but is happy to grow right out of the tank where it freely blooms with small white to violet flowers. I’ve gotten to the point where I usually just plant these at the back of the tank and let them go ahead and grow out. They can drape down the sides of the aquarium and be quite attractive if allowed to grow that way.
Pick Your Own
This is just a brief review of some of the aquarium plants that have been the most popular and easiest to grow over the history of the hobby. There are many more plants available, along with undiscovered ones that may become favorites in the future. Be sure to comment and let us know which plants are your favorite for the aquarium!
By David E. Boruchowitz
Blue eye (Cryptoheros spilurus). Photograph by Aaron Norman.
Central American lakes like Lake Nicaragua have a unique fascination. Some of our favorite small cichlids live there, as do large predators like the wolf cichlid (Parachromis dovii), not to mention the toothsome crocodilians and full-grown bull sharks on freshwater vacations. You can create a very interesting (if rough-house) biotope community around such a habitat—without the man-eating capabilities.
For this one we’re going to use a 6-foot tank, 18 inches wide, either the 100-gallon or one of the taller versions, like the 125. Substrate is a couple inches of natural gravel, and the bottom is broken up into visual territories with various rock piles, pieces of driftwood, etc. Caves and overhangs are important, since the cichlids we’re going to use are cave-dwelling and territorial. The 9 square feet of bottom area gives us the potential for three territories if all goes well, so make it look like three separate areas divided by rock formations, with the caves separated as wide as possible, preferably with entrances facing in different directions so a fish sitting in the doorway won’t be so tempted to go on border patrol.
Plants are not impossible, but their prognosis is guarded. Tough ones like Java fern, which don’t mind too much if they get shoved out of the way, or hardy Anubias growing on stones or pieces of wood are best. Potted plants might work, but if they cannot uproot them, cichlids often shred plants to make sure they will not harbor ambushing predators. You want powerful filtration, either a canister filter or a couple of large hang-on power filters.
For fish, we’ll choose three pairs of Archocentrus or related cichlids. You can pretty much take your pick from any of them, but if you select a milder species like Cryptoheros spilurus, you probably don’t want to also include bruisers like Rocio octofasciata or exCichlasoma salvini.
A good choice for variety, color, size, and compatibility would be three pairs selected from the following for species: convicts (Cryptoheros nigrofasciatus), blue-eyes (C. spilurus), firemouths (Thorichthys meeki), and flyers (Archocentrus centrarchus). All are readily available, about the same size, and of similar habits. To put some activity in the upper part of the tank, and to give the cichlids a target for their aggression, let’s add eight wild swordtails, three males and five females. If you do not want to go for an accurate wild species like Xiphophorus montezumae, then use green swordtails, which are close to the wild form of X. helleri. A school of a dozen Mexican tetras or their cousins, the blind cave tetras, (Astyanax mexicanus), finishes the stocking.
Swordtails complement this biotope and activity to the upper regions. Photograph by Ted Coletti.
If you can establish a dynamic peace, your cichlids might even spawn. It is doubtful you will raise any young, but with the tenacious parental attentiveness of these fish, it’s possible!