Name: Nematobrycon palmeri
When purchasing this fish, be aware that there are several species which are sold under the common name Emperor Tetra. The picture shown above is indeed Nematobrycon palmeri - indicated by its lack of adipose fin. A fish sold under the same name that does have an adipose fin will be a different species, and will not have coloured eyes, trailing fins or as much colour. Mistaking species in juvenile fish is common, but being aware of this differentiation will help make sure your fish will grow up to what you hope them to be!
These are beautiful fish. Peaceful, easy to breed, colourful, hardy, and long lived. About three years ago I set up a 200 litre soft water tank with lots of different Echinodorus species (amazon sword plants). My intention was (and still is!) to breed Mikrogeophagus ramirezi (Blue Ram), and I added half a dozen Otocinclus and two pairs of Emperors for variety. Three years and a major house move on, Rams and other dwarf cichlids have come and gone, the plants are now huge, the Otocinclus are still with me and going strong, and I have a constantly growing shoal of Emperors! Of the original four I still have three. These are massive, easily the biggest Emperor tetras I've ever seen, the surviving male is about 8 cm long, not including his tail, the central plume of which is nearly 3 cm long. His colours are stunning and his fins extremely long. How many young they've produced I don't know, but at least 30-40 must have grown to adulthood in the tank without any assistance from me. I keep fishing them out and selling them to local shops. They certainly aren't cannibalistic of their own young, in fact I wonder if they are mostly vegetarian in nature despite their fierce looking teeth. Mine love algae tablets. They do a lot of hiding in the undergrowth, apart from the adult males that come out to fight 'duels' in the open spaces. It looks impressive because it involves lots of fin shaking and circling (like fighting Bettas), but it is always completely harmless and a pleasure to watch, the worst that ever happens are a few fin nips and tears. Spawning usually takes place after a water change (I use cooler rainwater), the golden females are chased by the purple adult males through the undergrowth, sometimes the whole shoal gets involved, even the tiny babies. This is one of the few times I have observed shoaling behaviour, the other is when the fish get distressed for some reason, e.g. I am trying to catch them! I would recommend them for any planted tank with softish water, and think they would make ideal companions for Discus as well as South American dwarf cichlids and other tetra species.
I introduced about 12 emperor tetras when my first 380 liter tank was completely setup and mature. They got along well with the other tank mates (harlequin rasboras, cardinal tetras, flying foxes, and paleatus cories), despite the fact that they guarded portions of the tank where they tried to lure the females into spawning. From the original twelve the population grew to 35 in about one year. The fry arrived in groups of 6 to 8 individuals. That is when I decided to buy my second tank with capacity for 830 liters in order to give the emperors more room for romance. They have not stopped, since. I find new comers every three weeks or so. The amazing thing about these fish is that I do not need to do anything, like separating the fry from the parents, or giving them special foods, or changing any of the routines I have followed for the adults. However, both tanks are heavily planted with java ferns, half of the water is replaced every 7 days in both tanks, water conditions are strictly kept at 26°C, pH 6.5, 13 hours of light every day, UV sterilizer for both tanks, feeding is done twice a day (flakes in the morning, shrimp or blood worms in the evening, every day). I think that it pays off to treat my fish well, they reward me with their offspring, and that is just fine with me.
I have kept a group of twelve of these fish for a year now. The three males patrol little areas of the tank as breeding areas. They don't school much and hide quite a bit, even in my heavily planted tank. On the other hand, the colors are wonderful and it is a sight when the males display to each other. One little baby emperor has been hatched and grown in the tank! I bought these fish full grown and they haven't given me a moment of worry. Don't eat plants, don't bother other fish, eat anything I give them and haven't gotten sick.
I was lucky enough to find these tetras at our local pet store, but they only had three left. I try to get tetras in larger groups, but I purchased them anyway and they are doing great in my 270 liter community tank. The Emperors stick together and get along well with their tank mates these emperors are beautiful and look amazing in an aquarium. I only wish I could have gotten more.
I have kept emperor tetras for the last 3 months now and I have them in with harlequin rasboras, neons, cardinals and glowlight tetras as well as bumble bee goby's. The fish first picked on my neons and cardinals, but then I got about 20 more neons and they left them alone. They are nice fish, but don't get one for a long lasting fish because they have a life span of only about 2 years.