Emperor Tetra: Facts, Lifespan, Care, Feeding, & Breeding

The Emperor Tetra is said to live up to its name, with an appearance that is truly majestic.  It has a genteel personality to match!

The Emperor Tetra displays hues of primarily royal purple and rich yellow, which shift back and forth as it shifts and shimmers.  A stripe of black blends out into purple, which continues until it lightens near the fins and tail, which are yellow. 

A tank with dim lighting is said to really bring out the purple in the Emperor Tetra, whereas a tank with brighter lighting is said to bring out the yellow.  The fish arguably looks best in purple, with yellow serving as highlights on the edges, and a dark tank is also often preferred for more practical reasons. 

The flashy fish comes in more subtle color variations as well… pick your favorites if you are purchasing the fish in person.  Combine the fish with tank mates that will complement each other’s’ hues. The Emperor Tetra is one of the best fish for creating a gorgeous visual display in your tank!

Emperor Tetra Lifespan and Size

Upon purchase, the Emperor Tetra is around 3/4 -1.5 inches. The fish grows to be 1.4-1.7 inches in its adult years.  The males are bigger than the females, but the females are thicker, especially around the belly; these are two of the primary ways to tell apart the male and female Emperor Tetra.  When taken care of properly, the Emperor Tetra will live, on average, six years.  This is a respectable age for so small a fish, especially when one takes into consideration that the Emperor Tetra also mates and breeds relatively easily.

Emperor Tetra Behavior and Characteristics

The Emperor Tetra is a placid creature.  It keeps to itself, mostly, though it is known to interact more in schools and particularly in a mated pair.  Calm by nature, Emperor Tetra rarely shows aggression, though the male will posture and compete with other males. 

Occurrences of this sort can be reduced by providing plenty of space for your fish.  Be sure also to purchase either one pair or an equal number of male and female pairs of Emperor Tetra. This will help keep the waters peaceful.

Native to the San Juan and Atrato river basins in South America, Emperor Tetras can be found in areas with slow currents.  It is rare to find the fish anywhere else naturally.  Luckily, the Emperor Tetra is a popular fish breed among enthusiasts, and can, therefore, be found in pet stores almost everywhere. The Emperor Tetra can also be purchased online, singularly, in a pair, or a school.  A school may be the most cost-effective, and also make for the happiest fish, second only to a mated pair.  Again, make sure that there are not more males than females. 

Emperor Tetra Varieties

There are a few key variations of the Emperor Tetra, each boasting its own unique coloring and beauty. 

They are as follows:

Nematobrycon palmeri Source

●    The “original” Tetra, Nematobrycon palmeri, which is primarily blue and purple.  Its colors are bright and its form elegant, which is surely how this fish earned the name Emperor Tetra.

Rainbow Emperor Source

●    The Rainbow Emperor.  Experts recommend keeping this fish apart from other varieties, to avoid cross-breeding.  True Rainbow Emperor fish are becoming increasingly rare these days; which is a shame because they are stunning.  With this fish, the males have red eyes, and the female have blue-green eyes.

Black Emperor Tetra Source

●    The Black Emperor is a Tetra with an all-black, rich and velvety hue.  It is clear why this variation has come to be… the Black Emperor makes a stunning addition to any tank.  Consider combining Emperor Tetra varieties for best effect aesthetically.  The male Black Emperor fish have blue eyes, and the females have green eyes, which contrast against the dark scales of the variety beautifully.

Blue Emperor Tetra Source

●    The Blue Emperor.  Smaller than its Tetra counterparts, the Blue Emperor Tetra can be cared for similarly all the same.  It rarely surpasses 1.5 inches in size, so do not worry if it remains small in comparison to the others.

●    The Red Emperor.  Similar to the Blue Emperor, but red in color, the Red Emperor is also a small variety.  Both varieties are worth adding to your tank, as their hues are very vivid and will add dynamics.

Most fish get along best with their own kind, it seems, and the Emperor Tetra is no exception.  Pick and choose the colors of your Tetra and create a subtle rainbow.  Against the dark substrate and shade of the thick vegetarian, the fish will stand out in a fantastic display.  Make sure to include tank-mates that are comparable aesthetically, and you can feel pride as an enthusiast that your tank is truly extraordinary. 

Watching fish swim about is a singular experience.  Viewing the fish in a pleasantly lit, well-decorated environment, as they swim to and fro, makes the care of the creatures rewarding and well worth your while.

Emperor Tetra Nutrition

It seems to be a general rule that a mixed diet (of the proper foods) is a healthy one, as different foods offer different nutrients… it only makes sense that a combination would be the best way most effectively hit your requirements daily.

The ideal diet for the Emperor Tetra contains a few types of small foods, which include: small brine shrimp, small daphnia, bloodworms, and tubifex of the freeze-dried variety, mosquito larvae, high-quality flake food (small enough for their tiny mouths), and micro pellet food, primarily. 

Try a few of these options and see what your individual fish, or fishes, seem to like… though, from this menu, they are not likely to be picky!  Carnivores and omnivores do seem to relish live foods, however especially, so if you feel like treating your fish, give these a try.

If you have successfully bred your Emperor Tetra, feed the fry (baby fish) freshly hatched brine shrimp and infusoria.

Emperor Tetra Care

When preparing a tank properly, you must learn the individual needs of a given breed of fish.  The tank should imitate their place of origin in nature. 

The tank of the Emperor Tetra should reflect the slow-moving river basins of South America.  These rivers are vibrant with vegetation, which fills and covers the water so thickly that it is mostly in shadow.  So, likewise, include plenty of plants in the tank of an Emperor Tetra, dim the lighting, and slow the water current accordingly.  Use a dark, rich substrate.  All of this will make the Emperor Tetra feel at home, not to mention provide a stunning backdrop upon which you may view its activities each day.

Emperor Tetra Tank Mates

The Emperor Tetra can get along with most other fish.  It is not likely to have conflict besides that between a male with other Emperor Tetra males.  The Emperor Tetra does exceptionally well with friendly catfish, like Corydoras, as well as Rasboras, Danios, and, of course, other Emperor Tetras.  With the latter, a male Emperor Tetra may be most content with a few females, with no male fish for competitors, or with only one female mate.  If you wish to keep multiple males together, make certain that the tank is large enough to allow each of the Emperor Tetras their own territory… still, this is not advised.

When choosing tankmates, the most important things to take into consideration are, firstly, the temperaments of potential tankmates, and secondly, what they require environmentally.  Those which require a habitat similar to an Emperor Tetra will make it pretty straightforward to create the perfect conditions in your tank for the Emperor Tetra, and company.

Besides the obvious, which is avoiding aggressive fish for tankmates, you may also want to opt for fish which are not excessively sociable.  The Emperor Tetra is a good-natured fish and will interact prettily.  It does, however, need to be able to retreat at will and considers visitors into its area a nuisance, and pesky.

While large shrimp will serve as excellent company for the Emperor Tetra, small shrimp will likely be regarded as a snack.

Emperor Tetra Breeding

In fact, the Emperor Tetra male and female are relatively easy to distinguish, if you know how.  The most notable differences are that the male has blue eyes, and the female has green eyes.  Their eyes are iridescent, and may change slightly depending on the lighting; luckily there are other ways to tell the male and female apart, too.

As mentioned earlier, for example, the female is noticeably smaller than the male, with a similarly narrow body but a fat abdomen comparatively. 

The male also boasts an extended ray in the middle of its caudal fin, which the female does not have.

There is some good news for enthusiasts who wish to breed the Emperor Tetra.  When paired off, the Emperor Tetra will in fact breed with little to no stimulation necessary.  If you want to encourage your Emperor Tetras to mate, prep them with live food as you separate them for a day or two.  Then, remove them to their own tank.  This is particularly wise as males tend to become prickly at this time and will not be polite to others in the tank.

To spur the breeding process, all that you need to do, usually, is to provide a spawning mop, as well as or instead of some dense, floating plants or the like. 

The pH should be 7.0, as anything more acidic can cause digestive problems in the fry once they hatch (fry being a name for the baby fish).  The temperature should be around 82 degrees F.

Java moss seems to be a favorite of the Emperor Tetra.  It appears to encourage them to mate. Later on, the fry will hide in the moss as well.

Once the eggs are laid, it will take one to two days for them to hatch.  Make sure to remove both parents immediately after the eggs are laid, as they will probably feed on their own young otherwise.  Strangely enough, fish, as well as humans, seem to regard caviar as a delicacy. Perhaps, for the fish, it is the easy prey and nutrients.

You do not need to bother with decorations in the tank, as the fry grow relatively quickly and will probably not be spending long there.  Java moss and the like should be plenty.  Java moss contains rotifers, and baby Emperor Tetra likes to feed on this.

Emperor Tetra Young Care

Once the fry gets bigger than baby brine shrimp, reintroducing them to the primary tank safely becomes a possibility. Up until this point, as aforementioned, their parents will try to use them as sustenance.  But once they are larger than baby brine shrimp, adults have been noted to leave the fry alone.

When you perform water changes, use care!  The fry can easily be siphoned out along with the water, fatally.  Use a sharp eye, and if any little ones get in the way, promptly move them to safety. Check any removed water before disposal for stray fry. Precautions like this are what will ensure that your Emperor Tetra fry lives to maturity. 

If you succeed in this, you may find it a pleasure to watch them grow, and develop their own markings, colors… even, to an extent, their own personality.

When the tank reaches a certain capacity, Emperor Tetra will typically naturally cease to mate.  At this point, you may sell some of your Emperor Tetra, for profit, and/or to make more room in the tank.  You can obviously breed either to create a small school of Emperor Tetra of your own or to sell them to others.

The Emperor Tetra is a truly extraordinary fish. It is one of the easier fish to care for, and easy to maintain for its full lifespan of 6 years (sometimes more). With its sweet nature and amiability with other fish, as well as its magnificent vibrantly colored and iridescent scales, it is no wonder that fish enthusiasts consider the Emperor Tetra to be one of the most popular fish breeds available today.