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The Quick Guide to the Best Community Tetras

Diamond tetra. Photograph by Andrzej Zabawski.

By Lea Maddocks

In the January 2012 issue, I wrote about some of the best tetras available for beginners in the hobby.  The wide variety of shapes, colors, and behaviors of tetra species now available will leave most aquarists spoiled for choice when perusing their local fish store for new stock, and choosing can be a tough (but fun) ordeal. Tetras are also one of the first groups of fish new hobbyists begin with, as they are commonly available, small, colorful, and (generally) peaceful. Often, both new and long-term hobbyists will choose a tetra species or two to add activity and color to a community aquarium.

If you’re looking to purchase an one of the easier tetras, here is my quick guide to their basic needs and behaviors. For more information on any of these species, please check out my article.

Diamond Tetra

Size: 6 cm (2.4 inches)

pH: 5.5 to 7.0 for the best color, though tank bred specimens are very adaptable and can also tolerate more alkaline water, up to a pH of 7.5

Hardness: 5 to 12 dGH

Temperature: 24° to 28°C (75° to 82°F)

Tank Size: 75 liters (20 gallons) minimum, and at least 2 feet long. Ideally a 130-liter (35-gallon) or bigger tank is for better schooling behaviors and keeping a larger shoal. A 3 to 4 foot tank would be ideal

Tank Schooling Region: Middle to bottom, but generally all over

Notes: Prefers planted tanks with plenty of natural cover, this will bring out the best behaviours and coloration. Very peaceful. More in the school the better for effect and natural behaviours, minimum 6 per shoal, though 10+ is preferred.

Black Skirt Tetra

Size: 6 cm (2.4 inches)

pH: 6.0 to 7.0, though tank-bred specimens are very adaptable and will likely tolerate a range of pH from 6.0 to 8.0

Hardness: 5 to 20 dGH

Temperature: 20° to 28°C  (68° to 82°F)

Tank Size: 75 liters (20 gallons) minimum, and at least 2 feet long. Ideally a 130-liter (35-gallon) or bigger tank is for better schooling behaviors and keeping a larger shoal

Tank Schooling Region: Middle to bottom, but generally all over

Notes: Very forgiving of most water conditions and tank setups providing water is clean and the tank is cycled. Will be peaceful and co-habit well with most general community fish. The more that are in the school the better for effect and seeing their natural behaviours, with a minimum of six per shoal.

Buenos Aires Tetra 

Buenos Aires tetra. Photograph by Andrzej Zabawski.

Size: 7cm (3 inches)

pH: 6.0 to 8.0, the common tank bred specimens are very adaptable, they are reported to be happy between 5.5 to 8.5, one of the biggest ranges for a tetra

Hardness: 2 to 20 dGH

Temperature: 18° to 28°C (64° to 82°F)

Tank Size: 130 liter (35 gallon) minimum, at least 90 cm (3 feet) long to provide adequate territories and swimming space for this active fish. The bigger and longer the tank, the better. Would be a great choice for a standard 4 foot long, 200 liter (55-gallon) tank

Tank Schooling Region: Middle to bottom

Notes: A very hardy fish, likely to adapt to most tropical fresh water chemistries and temperatures. It is an active species which requires a good deal of open swimming space along with some cover to retreat into. Peaceful despite its active nature, though best kept with tankmates of a similar size and disposition, and bottom dwellers. Makes a great dither fish. Keep in shoals above eight to ten or more individuals to keep any pecking order activity among themselves.

X-Ray Tetra

Size: 4.5cm (1.8 inches)

pH: 6.0 to 8.0

Hardness: 2 to 30 dGH

Temperature: 24° to 28°C (76° to 82°F)

Tank Size: 40 liter (10 gallon) minimum. Ideally a 55-liter (15-gallon) tank or bigger will be better for schooling behaviors and keeping larger shoal

Tank Schooling Region: Middle to bottom

Notes: Given the annual flood cycles of its native waters, it is a very adaptable species that will fare well in just about any municipal water chemistry provided it’s kept clean and at the appropriate temperature. A very peaceful fish, it is best kept with other small and non-aggressive species. More in the school the better for effect and natural behaviors, minimum six per shoal with ten or more preferred as they will be confident in larger numbers.

Bloodfin Tetra

Bloodfin tetra. Photograph by Andrzej Zabawski.

Size: 5.5cm (2 inches)

pH: 6.0 to 8.0

Hardness: 5 to 20 dGH

Temperature: 18° to 28°C (64° to 82°F)

Tank Size: 75 liters (20 gallons) minimum, and at least 2 feet long. Ideally a 130-liter (35-gallon) or bigger tank is for this active swimmer

Tank Schooling Region: Top to middle

Notes: Very forgiving of most water conditions, providing water is clean and the tank is cycled. Will be peaceful and co-habit well with most general community fish. Excellent planted tank choice. More in the school the better for effect and natural behaviors, minimum six per shoal though eight to ten are better to prevent skittishness and reduce any minor intra-specific nipping.

Hockey Stick Tetra

Size: 6 cm (2.4 inches)

pH: 6.0 to 8.0, though tank bred specimens are very adaptable and will likely tolerate a range of pH from 5.5 to 7.5

Hardness: 5 to 20 dGH

Temperature: 22° to 28°C (72° to 82°F)

Tank size: 70 liters (20 gallons) minimum, at least 2 feet long. Ideally a 3foot long, or 130-liter (35-gallon) or bigger for keeping larger shoal and territorial behaviors in check

Tank schooling region: Top to middle.

Silvertip Tetra

Size: 5 cm (2 inches)

pH: 5.5 to 8.0

Hardness: 5 to 20 dGH

Temperature: 23° to 28°C (74° to 82°F)

Tank Size: 70 liters (20 gallons) minimum, at least 2 feet long. Ideally a 3 foot long, or 130-liter (35-gallon) or bigger for better schooling behaviors and keeping larger shoal

Tank Schooling Region: Top to middle, but generally all over

Flame Tetra

Size: 4 cm (1.6in)

pH: 5.5 to 7.8

Hardness: 2 to 20 dGH

Temperature: 22° to 28°C (72° to 82°F)

Tank size: 55-liter (15-gallon) minimum. Ideally 75 liters (20 gallons) or bigger for better schooling behaviors and keeping larger shoal

Tank Schooling Region: Middle, but generally all over

Lemon Tetra

Size: 4 cm (1.6in)

pH: 6.0 to 7.5

Hardness: 5 tp 20 dGH

Temperature: 22° to 28°C (72° to 82°F)

Tank size: 55-liter (15-gallon) minimum, or 2 feet long at least. Ideally 75 liters (20 gallons) or bigger for better schooling behaviors and keeping larger shoal

Tank schooling region: Top to middle

Posted December 21st, 2012.

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TFH Classic: New Discoveries in Peru


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.

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TFH Classic: Salt and Other Sailfin Secrets

Sailfin molly. Photograph by Mark Smith.

By Robert Bock

From TFH December 2002

There are many controversies surrounding mollies. In this article, the past president of the North American Native Fishes Association reports his investigations and findings.


Want to start an argument among molly enthusiasts? Just bring up the subject of salt. One camp will say that you don’t need salt in the water to raise big, beautiful, sailfin mollies. Salt just allows lazy aquarists to compensate for dirty water, they say. It simply kills off the opportunistic bacteria and other parasites that victimize fish whose immune systems are stressed by the high nitrogen levels found in poorly maintained tanks. Keep fish densities low, do regular water changes, and you’ll have no problems raising big, beautiful sailfins that will be the envy of your fish club.

Not so, says the salt camp. Everyone knows that the biggest, most beautiful sailfin mollies come from saltwater habitats. Raising sailfins in fresh water produces, at best, small, stunted offspring that bear only faint resemblance to their wild forebears.

Who’s right? After keeping these beautiful fish for a few years, and conducting a little at-home research, I’ve come to the conclusion that they both are. For starters, sailfin mollies consist of three species, two of which are the most important for aquarists. Poecilia latipinna is found from South Carolina through Florida, along the Gulf Coast, and into Mexico. In the more southerly part of its range, P. latipinna is replaced by P. velifera, found along the coastal waters of the Yucatan Peninsula in Mexico.

These species resemble each other greatly, the major difference being that P. velifera usually has a larger body size, and the males have a larger dorsal fin than do males of P. latipinna. Male P. velifera have from 16 to 19 dorsal rays; male P. latipinna have only 12 to 14 rays. Both species inhabit brackish and freshwater habitats along the coast.

Commercially raised sailfin mollies come in an assortment of colors: black, white, mottled, yellow, and orange. In recent years, my favorite variation, the wild type “blue” sailfin molly, has started showing up in aquarium stores. The genetic pedigrees of these store-bought mollies vary greatly. They may be descended from P. latipinna or P. velifera, or hybrids of the two species, or from a hybrid of one or both species and some other related poeciliid species. Because of their mixed parentage, some of these mollies may not produce offspring capable of surviving on their own.

The Quest

I began my quest to raise the biggest, best sailfin mollies I could about four years ago. My friend, B. G. Granier, sent me a batch of wild-caught sailfin mollies, P. latipinna, from near New Orleans, Louisiana.  They were among the most beautiful creatures ever to grace my fishroom. There were about 10 males in the group, all of them shimmering azure and silver, each trimmed with orange on the face, dorsal, and tail fins.

Some people believe salt is needed to raise big, beautiful sailfin mollies, while others do not. Photograph from TFH Archives.

One by one, I watched them slip away. It began with a slight wobble. Their condition grew worse, until they could barely hold steady in the water. Eventually, they developed a downward curving spine.

At first I thought it was a contagious disease, brought in from the wild. I treated them with a variety of medicinal products. Nothing worked. One after another, they began to die. I wondered if it would be best to swear off this beautiful species for good before I killed any more. B. B. had warned me that they might need a little salt in their water to do well. But what I’d read said that salt was unnecessary, so I hadn’t added any.

The remaining male lingered in a quarantine tank. I pondered his curved spine and how much he reminded me of an older woman with osteoporosis. Perhaps he didn’t have a contagious disease. I remembered how some women develop osteoporosis later in life when they lack calcium in their diets during their reproductive years. Maybe this fish had a nutritional deficiency resulting from a lack of calcium.


I didn’t have anything left to lose. If I didn’t try something soon, the fish would probably be dead in a few days. So I dumped a tablespoon of garden limestone into the water. Limestone, I reasoned, is largely calcium carbonate and might provide a nutritional boost to help the fish hang on.

Soon after, the wobbling stopped. Although his spine never straightened out, this male lived on for many more months. Limestone, I soon learned, forms clumps and really doesn’t dissolve very well in water. Eventually, I began using another source of calcium carbonate—the Rift Lake salt favored by cichlid keepers. Within a couple of years I had four sailfin breeding tanks and an Everglades biotope tank crowded with sailfin mollies. Wild sailfin females are a drab gray, resembling large female guppies. To add a little color to the tank, I began keeping orange and mottled sailfins I bought at the aquarium store.

According to the books and articles I’d read, sailfin mollies inhabit salt water, brackish water, and fresh water. In an aquarium they would do well under any of these conditions. But what I’d read hadn’t explained why the fish seemed to need a calcium-rich environment.

Salt or Calcium?

A short time later, I happened upon the work of Joel Trexler, an ecologist at Florida International University in Miami. Dr. Trexler studies the effects of environmental influences on evolution. One of his major research interests is on how environment influences the development of sailfin mollies. I told Dr. Trexler about how adding garden limestone to the tank saved my sailfins from certain doom. He explained that sailfins are more suited to life in salt water than in fresh. Specifically the gill structures of sailfin mollies have osmoregulatory systems more like those of marine species. Osmoregulation refers to a fish’s ability to maintain the balance between the sodium and other minerals inside its body and the sodium and mineral concentration of the water it lives in.

Many fishes, including sailfin mollies, can use calcium in place of sodium for maintaining their osmotic balance, he said. For sailfins, water with high carbonate hardness also explains the distribution of sailfin mollies, at least throughout the East Coast. At the top of their range, in South Carolina, P. latipinna are confined to the salt and brackish waters along the coast. In southern Florida, their range extends across the peninsula. Much of south Florida sits atop ancient coral beds, and so its water have fairly high carbonate hardness. Similarly, P. velifera are either found in saltwater habitats or in limestone springs, and the geology of the Yucatan has much in common with southern Florida.

Calcium carbonate works the same way as salt when added to the molly aquarium. Photograph by Mark Smith.

One caveat is worth inserting here. A few populations of sailfin mollies might be genetically adapted to survive without salt or calcium carbonate. Virtually all the mollies I’ve kept die if they aren’t kept in very hard water, with a pH of at least 7.8. However, Bill Allen, of the American Livebearer Association, has told me of a drainage ditch full of sailfin mollies in Shreveport, Louisiana, about 200 miles from the Gulf Coast. The mollies there are apparently thriving in a pH of about 7.0, with total dissolved solids of less than 100 parts per million.

To complicate the great salt debate even further, many aquarium strains of sailfin mollies may have resulted from crosses with other freshwater species. In an email, Trexler told me that long-time commercial fish breeder Ross Socolof had told him that the aquarium black molly strains were developed from crosses between P. velifera and the  freshwater species, P. sphenops. For this reason, P. sphenops genes may have provided some strains of commercially available sailfins with a greater tolerance to fresh water than their wild-caught cousins have. However, with one or two exceptions, the store-bought sailfins that I’ve kept have done better in sea water than they have in fresh.

Salt and Calcium?

Although sailfins need calcium carbonate to maintain their osmoregulatory system, I have a theory that—because of the hunched backs that my fish developed—they may also have a higher nutritional need for calcium than other fish do. The males’ large dorsal fins contain numerous elongated rays, which may require extra calcium to develop. Dietary calcium may be available to them in algae and microscopic crustaceans they eat, having been absorbed by the latter from the water they live in.

I should point out, though, that Trexler questions the need for extra calcium in the sailfins’ diet. Armored catfish, he said, come from a soft water environment with little calcium and don’t seem to need any extra calcium to develop their armored plating. Since no scientific studies have been done on sailfins and dietary calcium, however, there isn’t any evidence to prove either of us right or wrong.

The Data

The varied conditions that wild sailfin mollies live under provide a natural laboratory that Trexler’s group employs to study the effects of environment on an organism.

One of his group’s experiments, in particular, is relevant to aquarists. He and his coworkers collected sailfins from four different locations throughout Florida. They raised the offspring of these fish under a combination of different conditions to see how those conditions might affect the fish’s development.

The scientists raised the mollies individually in 5-gallon aquaria in water with three different concentrations marine salt, 2 ppt (parts per thousand), 12 ppt, or 20 ppt. The fish were kept at a temperature of either 74° or 84.2°F and were fed either the maximum amount of food the fastest-growing individuals could eat in one day, or half that amount. The scientists reared groups of fish in each of the 48 different combinations possible.

Before beginning the study, Trexler and his colleagues did some informal tests to determine if the fish actually needed salt. The researches learned that the mollies grew more slowly and were more likely to die from fungal infections in water that had no salt. In water with 2 ppt salt, virtually no fish died.

Surprisingly, the amount of food the fish were given—a good quality flake—didn’t vary enough to have an effect on their final size. The greatest size at maturity, however, was reached by fish kept at 84.2° in water with a salinity of 2 ppt. Although their gill structure suggests that sailfin mollies do benefit from some salt in the water, that amount doesn’t seem to be that high. It’s worth noting here, also, that Trexler’s study tested only three salt concentrations, so it’s impossible to generalize from them which salinity level mollies favor most. It does seem reasonable to conclude, however, that the ideal salt concentration for most sailfin mollies lies somewhere between 2 ppt and 12 ppt.

The lack of an influence for high salinity on body size, however, is puzzling, particularly in light of other, seemingly contradictory findings. In field studies, scientists have observed that the largest sailfins were found at higher salinities in their wild habitats. Similarly, in another experiment, Trexler and his colleagues found that, in outdoor cages, mollies grew larger in sea water than they did in fresh water. The researchers theorized that some unknown condition in the wild might favor the development of larger size at higher salinities. I’ve observed much the same thing in my own tanks. The sailfin mollies I raise in artificial sea water also seem to be larger than those I raise in fresh water.


I suspect that the unknown condition may be diet. According to Trexler, sailfin mollies are largely herbivores. Like mammalian herbivores, they have long, winding digestive tracts suitable for digesting plant matter. He and his coworkers have analyzed the stomach contents of wild sailfins and found them to contain mostly algae. So, too, mollies kept in aquariums spend nearly all their waking moments grazing on algae.

My hunch is that the faster growth I’ve seen in my saltwater aquariums and that Trexler and his group saw in their saltwater cages could be from marine microalgae. Marine microalgae may be more nutritious for sailfins than freshwater microalgae is. Alternatively, marine microalgae may simply be more palatable than freshwater microalgae. Mollies that I’ve kept in saltwater tubs in summer and in brightly lit saltwater aquariums in house always look well fed, even when I hadn’t fed them for a couple of weeks. In contrast, freshwater mollies I’ve kept under the same conditions in freshwater always look underfed. The freshwater microalgae seems to be harder than the saltwater microalgae, and so I think the fish simply can’t consume enough of it to meet their needs.

My hunch is that if you can feed mollies a sufficient amount of food in either hard fresh water or in 2 ppt sea water, they will grow as large as mollies kept in brightly lit seawater environments.

To test this, I’ve divided baby molly siblings from the same wild-caught mother into two groups. I’m rearing one in sea water and another in hard fresh water. Except for the salinity, I’m keeping both groups under nearly identical conditions. To make sure they get enough to eat, I allow both groups to graze nearly all day on cubes of high density food I make myself.

I feed homemade cubes because I don’t think it’s possible to raise large mollies on a diet of dry flake food, unless, perhaps, you can find the time to feed them a dozen or so times a day. Dry foods are less dense than pellets and frozen cubes, so feeding flakes two or three times a day, as most aquarists are able to do, simply won’t supply them with the comparable amount of nutrition they could get by grazing on marine microalgae all day.

To make my pellets, I begin by soaking high quality cichlid pellets until they’re water logged. As most aquarists know, fish can die if they eat too much dry food; the food takes on water inside the fish’s digestive tract, and the fish’s digestive organs burst. In contrast, fish can eat as much water-logged food as they like. I mix the pellets with an equal amount of unflavored gelatin other ingredients and turn on the blender until I have a dense slurry. I pour the slurry into empty plastic frozen fish food containers to form individual portion sizes, then freeze portions until I’m ready to use them.

Currently I’m still experimenting with the food mixture, and I’ll often add frozen brine shrimp, cooked peas, soaked flake, and marine macroalgae.

It’s been about a month since I’ve started keeping two groups of fish under these conditions. So far, the freshwater sailfins seem to be keeping pace with their saltwater siblings.

One promising idea that I hope to get around to eventually is to provide mollies kept in fresh water with algae grown in sea water. One way to do this would be by rotating algae-covered rocks from a seawater tank through the freshwater tank.

Growth Dimorphism

Another important lesson to learn from Trexler’s study of environmental conditions is how female body size is influenced more by environment that is male body size.

Although their environment clearly influenced the size of both sexes, female mollies reach their greatest size largely because of environmental conditions favorable to growth, whereas males reached their largest size because of the genes they had inherited. This finding confirms earlier studies, which suggest that male body size depends largely on a number of different genes. Male sailfins mature at various stages of development. When they reach sexual maturity, they stop growing.

The implication for hobbyists, though, is clear: If you want to raise a strain of large, colorful sailfins with big sails, it’s best to start with large male breeders. Keeping small males in the hopes that they will reach a large size, then, is fruitless. Instead, small males should be ruthlessly culled from the breeding tank, as their sons will also be small.

Personally, I select for female size and color. Although I prefer the coloration of wild-caught males to that of their store-bought cousins, female wild-type sailfins are rather drab. Right now, I’m trying to introduce some color into the females, both with store-bought orange varieties and with wild-type females having some faint orange coloration. If I come across an outstanding wild-type male, I’ll add him to my breeding stock, both to add new male genes and to prevent inbreeding. I don’t pay attention to whether my breeders are P. latipinna or P. velifera. Since both species interbreed freely, I’m not interested in maintaining a pure strain, just in producing an outstanding strain of blue males for the aquarium.


So, what about the Great Salt Debate? Mollies probably have the best chance for thriving if they are kept in water that is at least 2 ppt salt or has a pH of 7.8 or higher and is hard and alkaline. Although mollies will greedily take meaty foods such as insect larvae and brine shrimp, they are herbivores. No matter what  you feed them, it’s probably best to keep them with an abundance of algae to graze on.

Because they graze continually, sailfins produce large amounts of ammonia-containing wastes. For this reason, tank densities should be kept low. Low tank densities not only keep down levels of ammonia and other wastes, but also prevent stressful competition between males. The high pH that sailfins favor increases the ammonia’s toxicity, so would-be sailfin keepers need to take extra pains to keep ammonia levels down through frequent water changes, good filtration, and perhaps with the assistance of ammonia-absorbing, fast-growing plants.

For freshwater sailfin tanks, I grow Italian vals (Vallisneria spiralis), in salt water, the marine macroalgae Caulerpa taxifolia. Bright lighting will not only stimulate plant growth, but also that of macroalgae the mollies need to graze on. Although they’ve been in the hobby for many years, sailfin mollies are not a beginner’s fish. They do require some extra work, and some extra thought. But the beautiful colors of both store-bought and wild-caught fish, plus the magnificent sail stretching display of courting males, merit the attention of serious aquarists.


I’d like to thank Dr. Joel Trexler for his careful review of this manuscript. Articles on wild sailfin mollies are available on the website of the North American Native Fishes Association In addition, the American Livebearer Association has an excellent compilation of past articles on mollies


Posted November 21st, 2012.

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Best Plants for Beginners

By Lea Maddocks

As Lea Maddocks explains in the second part of her article in the December 2012 issue,  Setting Up a Successful Low-Tech Planted Tank Like a Pro, Part 2: Aquascaping and Maintaining Your Planted Tank, choosing aquatic plants that fit your skill level and fit the look that you want can be challenging. However, some plants have a reliable track record of doing well in low-tech setups.

Let’s start with the best epiphytic plants. These should not be planted in the substrate, instead they can be tied to rocks or stones and allowed to grow with their roots exposed.

Java fern and Java moss are both very hardy plants. Photograph by Gary Lange.

Java fern varieties (Microsprum pteropus) including regular, crested (aka ‘windelov’), and narrow leaf

Anubias species

Congo fern – Bolbitus heudelotii

Mosses, including Java moss

Next come floating plants. Similar to epiphytic plants, these should not be buried in the substrate. Instead they should be left floating freely in the aquarium. They are great for providing shade to skittish fish.

Duckweed is an easily grown floating plant, but be warned that it can easily reach plague proportions. Photograph by Albert Connelly, Jr.

Hornwort (Ceratophyllum demersum)

Lacefern/watersprite (Ceratopteris thalictroides)

Duckweed (Lemna minor)

Mosquito fern (Azolla caroliniana)

Brazillian pennywort (Hydrocotyle leucocephala)

Water lettuce

Some stem plants are appropriate for beginners. These must be planted in the substrate.

Green hygro (Hygrophila polysperma) is a relatively easy-to-grow stem plant. Photograph by MP. & C. Piednoir.

Some ludwigia, including the red Ludwigia repens

Elodea/Egeria – Egeria densa

Green hygro (Hygrophila polysperma)

Water wisteria (Hygrophila difformis)

Lacefern/watersprite (Ceratopteris thalictroides, note this can be planted as a stem plant or left floating)

Brazillian penny wort (Hydrocotyle leucocephala)

Bacopa – Bacopa australis, B. monnieri, Bacopa caroliniana


Myriophyllum mattogrossense

Amazon swords, the ozelot variety has red flecks and can be great for color

Rotala rotundifolia

Cryptocoryne species, especially browns like C. Wendtii, C. Lutens

Pearlweed (Hemiantus glomeraturs), which was formerly confused with H. micranthemoides

Saggitaria and dwarf sgaggitarita

Pygmy chain sword (Helanthium tenellus)

Posted November 16th, 2012.

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Planting in Non-Ideal Conditions

Lea Maddocks

In the November 2012 issue of TFH, professional aquascaper Lea Maddocks writes about how a beginner can easily set up a planted tank in her article Setting Up a Successful Low-Tech Planted Tank like a Pro, Part 1: The Basics. While setting up a tank from scratch is perhaps the easiest way to create an aquascape, sometimes you have to work with what you have. Here Lea offers her advice for how to create a lush aquascape even if your existing tank has less-than-ideal conditions.

Difficult Livestock Choices

The hardness for African cichlids or brackish fish like mollies is often too high for many plants, though some species such as Vallisneria, Anubias, Bacopa, Elodea, hornwort, water sprite, some crypts, Sagittaria, and Java fern, among others, may still do well.

Many plants also will not tolerate colder water used for goldfish, danios, white clouds, or other more temperate fish, though Elodea, Vallisneria, swords, Anubias, Java moss, and hornwort will thrive. Research your desired plant species online and through plant specialists to know for sure what you can and cannot plant due to water chemistry and temperature limitations.

Less-Than-Ideal Grain Size

If your grain size is outside the ideal range of 2 to 5 mm do not be concerned, for here is a useful tip: You can use epiphytic plants, floating plants, plants already planted in floss, and potted plants. A well planted tank can be devoid of substrate if this tactic is used.

Epiphytic plants are those which do not need, or even like, to be planted, and instead need to be attached to driftwood, rocks or other ornaments with cotton thread where they will eventually secure themselves with roots used purely as hold-fasts. Such plants also require no nutrients from their roots, and absorb all they need via their leaves. Many also have the advantage of being adaptable to low or poor quality lighting, and are very hardy.

Floating plants are also an excellent option here, and many will thrive in almost any healthy tank as they have several advantages over submerged plants. The first is that they are very close to the light. Even with a weak lighting system, these plants will often get all the light intensity they need as they are usually less than inches away from the light source, and the light generally does not even have to penetrate the water to get to them. Do note that even with good intensity some plants can suffer if the spectrum is not correct, so check out my article for lighting advice. The second benefit of floaters is that in many cases the leaves actually sit on the surface exposed to the air, which is far richer in CO2 than the water. When this is the case, the limitation of dissolved CO2 is removed, and plants often grow well with nutrients obtained from fish and food waste.

If you are wish to plant non-epiphytic plants in a non-ideal sized substrate, planting in floss or potted plants may be the answer. Both of these approaches are simple. Wrap the roots of your chosen plants in a generous amount of filter floss, add root tab or fertiliser ball, and add another floss layer. These tabs/balls slowly release fertilisers and micro-nutrients to supplement larger root systems. Bury the lot gently within your substrate, and make sure to add a layer of your substrate over the top or some pebbles around the base to hide the floss and keep it weighted down. The roots will grow well in the floss, as they can penetrate it easily, though it is dense enough to provide a good structure for the root system. It is also porous enough to allow a great flow of oxygenated water and dissolved nutrients around the roots, and a large area for nitrifying bacteria.

It works in a way akin to plants in a hydroponic system. Once the plant is established, I find that there is usually no need to replace fertiliser tabs/balls the level of accumulated mulm will do the work for you. However, if your plants start to yellow or show other signs of deficiency, by all means add another tab—it certainly won’t hurt.

Alternatively, the same strategy can be used with pots for an interesting feature. Many kinds of pots, cups or containers can be used including terracotta, small bonsai pots, sake cups, or any ceramic pot which is dishwasher safe (dishwasher safe indicates that the glaze is safe and will not leech toxins into the aquarium water). Indeed, a well decorated tea-pot or cup could make a novel feature in your tank!

Photograph by Lea Maddocks

Posted October 18th, 2012.

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Keeping Altolamprologus Species

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.

Altolamprologus Basics

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?

Posted August 24th, 2012.


Spawning Pygmy Cories

By Jennifer Wilkinson


Pygmy cories appreciate a well planted tank with plenty of cover. Photograph by Mark Smith.

The pygmy cory (Corydoras pygmaeus) is found in South America, but was originally discovered in the Rio Madeira system. They seem to be readily available to aquarium hobbyists at certain times of the year.

This dwarf cory can reach about an inch in length. It is a grayish brown color on the top and a lighter gray on the bottom. The two colors are divided by a dark line that runs the length of the body to the caudal peduncle. The line ends with an almost round dot on the caudal peduncle, which is surrounded in a lighter color. The rest of the caudal peduncle and fins are a clear color. The females are slightly larger than the males and especially when ready to spawn. C. pygmaeus are part of the elegans group, along with C. elegans, C. hastatus, C. undulatus, C. latus, C. guapore, C. nanus, and C. gracilis.

Cory Behavior

Pygmy cories can be found on the bottom of the aquarium, like most other cory species. However they also like to swim in midwater, about 4 inches from the bottom. They also have the capability to hover in one spot. I have kept many species of Corydoras and have found that not too many do this. If the aquarium is set up properly so that the dwarf corys are comfortable, they will be seen dashing about all day long.

If there is any motion around their aquarium or if they feel threatened they will dash off into a hiding spot. If they can’t find a hiding spot, they will come to a standstill on the bottom of the aquarium and only begin to move again when they feel the danger has passed. All the Corydoras I have kept seem to be more comfortable in an aquarium that has lots of caves, rocks, flower pots, and live and plastic plants. They seem to be more comfortable if they are under something, so providing some kind of cover is necessary. They will also dash up to the top of the aquarium to get a gulp of air.

In the aquarium they prefer to be in large groups of the same species or with other species of Corydoras of about the same size, as they are very social little fish. I usually recommend that all Corydoras be purchased in groups of three or more because of this social behavior. If at all possible, I recommend at least six, and more is definitely better with these little fish, especially in a community aquarium. In the wild these fish are found in very large groups, hundreds or thousands are not unheard of.

Bringing Them Home

I had to special order my fish from one of the pet shops I was dealing with at the time. I ordered 20 C. hastatus. When I went to pick my order up, I questioned the owner about the fish he got in. When I examined the lot, I was sure that they were not C. hastatus but C. pygmaeus. It didn’t really matter to me which one they were, as I didn’t have either one. However, the store assured me they were C. hastatus.

They were very young, approximately seven weeks old, so it was very difficult to tell just what they were. The store owner threw in two extras just in case he counted wrong. So, on the way home from the store, I wondered just what kind of fish I had and just how many I had.

When I got home I placed my tiny cories in a 20-gallon aquarium by themselves. The parameters of this aquarium were a temperature of 78°F, the pH was 7.0, and the water was soft. This aquarium was filtered with an appropriately sized external power filter with a sponge on the intake tube so these little fish wouldn’t get pulled in. Water changes were done twice a week, with about 30 percent being changed each time.

The fish were raised and conditioned on sinking wafers, several different kinds of flakes, and baby brine shrimp. After four months a few eggs were found and I was surprised to find that there was also one half-grown baby. The eggs and the one baby were moved to a 5-gallon aquarium. Two days later, all of the eggs had fungused, so I decided to move the one tiny fry back in with the adults. Unfortunately two days later he was found belly up on the bottom—he probably couldn’t handle the stress of being moved so often.

Real Breeding Attempt

Shortly after, more eggs were found. This time, after doing lots of research, I was ready to try some different techniques. What works for one hobbyist may not work for the next, so I was prepared to have many flops before actually getting a viable spawn. This time I tried suspending a net in the main tank, with a gentle flow of air bubbles under it. Then I collected the eggs with my fingers and put them gently in the net. All the eggs fungused by the next morning.

The next batch of eggs were moved into a shallow glass pan with no air stone or filter. This time they hatched, but all was lost again three days later. I believe polluted water was the cause this time. These fry are really tiny, and certainly not near big enough to eat baby brine shrimp, so a liquid fry formula was fed. Obviously way too much of this, as the water became very cloudy and a water change wasn’t done fast enough. After this I gave up for a while, or I guess you could say I took a break.

I have used this shallow glass pan method several times now with other cories and Aspidoras spp. with great success. The difference being, as soon as the fry hatch and fall to the bottom, they are transferred to larger quarters (an aquarium) to be fed. More water means less pollution. Liquid fry foods are no longer used, instead artificial plankton rotifers are used until baby brine shrimp can be fed. Lots and lots of water changes are a must. If only I would have known at the time.

Success at Last

I finally had success with these pretty little corys when I moved them into another 10-gallon aquarium down in the fishroom. They were brought into breeding condition on sinking wafers, frozen blood worms, several different kinds of flakes, and occasionally freeze-dried and frozen adult brine shrimp. The parameters of this aquarium were exactly the same as the aquarium they were in previously. For some reason there was a plastic livebearer breeder trap sitting in this aquarium. I have no idea why, as there was never a fish in it.

Anyway, this was the chosen site for the C. pygmaeus to deposit their eggs. It was covered. Unfortunately I did not witness this spawning, just found the eggs. The eggs seemed slightly smaller than those of the other Corydoras that I have raised, but developed the same way.

First a dark line appeared, and as they aged it got larger and darker, and they hatched and the fry dropped to the bottom. Their first food was artificial plankton rotifers, as they were too small to eat the baby brine shrimp. This was fed every three days, and a 30 percent water change was done every three days before the new food was added.

Water changes have to be done very carefully with a hand siphon so as not to pull the tiny fry out. This still happens, however, and most can be put back in with an eye dropper without causing them any harm. This can sometimes cause problems with broken backs or other damage, where the fry end up dying, so it is best to take it slow and easy and try not to pull them out.

After two weeks they started to eat the baby brine shrimp, so the artificial plankton rotifers were stopped. With the baby brine shrimp, 50 percent water changes were done every night. At the four to five week stage, flakes and sinking wafers were added to their diet.

These little fish had dark broken lines and looked more like C. habrosus than C. pygmaeus until they were seven weeks old. That is the time when the solid line showed up and they looked just like their parents.

Persistence Wins Out

Sometimes persistence pays off, and so does doing lots of research. However, in the end it was just some good luck and a plastic livebearer breeding trap.

These are very nice fish to add to a community aquarium, as they are so peaceful. The only problem is to remember that they can only be housed with smaller fish, such as small tetras and rasboras. I accidentally put six young angelfish in with some and let’s just say they angelfish were definitely not angels, they thought these little cories were a tasty treat. I removed them quickly to save what was left. Beginners do make mistakes—but I quickly learned from mine.

Posted August 9th, 2012.

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Essential Fishroom Questions

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.

Posted August 3rd, 2012.

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August 2012 Calendar

Tropical Fish Hobbyist’s August 2012 Desktop Calendar is now available!

Click on the size below that best matches your desktop.




Visit the Web Extras section of for additional downloads, videos, and much more!

Posted August 1st, 2012.

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5 Fantastic Aquarium Plants

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!

Posted July 27th, 2012.

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