First Zig, Then Zag
Zigzag Tetras are rad. That could be the end of it, but wait, there's more! Scientifically known as Hyphessobrycon hexastichos, they're also commonly called Six Stripe Tetras, and are occasionally, (and incorrectly) sold as Redline Tetras, which are a different species altogether (Moenkhausia agnesae). Both these species look fairly similar, but Redline Tetras get almost twice as large and are a bit more pugnacious. On initial examination, the Sixline name seems to make more sense, but when you look closely at those (six) lines, you see that they are actually all made up of fine zigzag markings. Their bodies are silver with metallic blue/green highlights along their back (and sometimes sides), and the stripes can range anywhere from black, to brown, grey, red, orange, or even yellow!
These are small Tetras; adults rarely get longer than two and a half inches. Combine this with a fairly docile temperament and you get a fish that can be kept in a relatively small aquarium. Like most Tetras, these will need to be kept in groups; the more the merrier. We suggest at least seven, and a much better situation would be more than a dozen. For a group this size, a 30-gallon set up would leave some capacity for other fish, and a 40g or 55g tank leaves tons of room for activities (more fish).
Originally, Hyphessobrycon hexastichos are from the very upper regions of the Rio Tapajos in Brazil. A display that mimics this would have a soft sand substrate, with perhaps some large rocks and driftwood or riparian roots for cover. They also do well in planted aquariums. A good amount of cover is key to keeping these groups and their social hierarchy healthy. The water from their wild home is clear, warm and slightly acidic. Shoot for a pH between 5.5 and 7.5, with a temperature between 75 and 82. The river they come has very soft water, but the fish seem to do just fine in a range of hardness, as long as it isn't extremely hard. They do like clean water, so keep up those water changes, and utilize strong filtration. Keep in mind that most of the ZigZag Tetras you're likely to encounter now are aquacultured (and have been for many generations), so adhering to the exact wild water chemistry parameters isn't a necessity; if you opt for wild caught fish, stricter adherence is a better policy.
As we touched on briefly, Zigzag Tetras are a peaceful group. This should be your focus when choosing tankmates. In regard to tank mates, they'll do well mixed with other small Tetras, as well as Angels, Hatchetfish, Plecos, small Cichlids and Cats. Corydoras are a favorite pairing around here, as they'll bring activity to the lower reaches of the aquarium where the Tetras mostly aren't. Things to avoid are (obviously) predators big enough to eat our Zigzags, and other large boisterous (or aggressive) fish that might bully them into hiding.
Tetras aren't the easiest fish to breed, but they aren't the hardest either; Zigzags are no exception. The first challenge is sexing them. The males are slightly more vibrantly colored. To get around this, you can group spawn them or try to cordon off a single gravid female and a colorful male. Parents should be well fed to bring them into breeding conditions. They need to be separated from the eggs, which can be done with a marble substrate, netting, or even fine leaved plants / spawning mops and removing them from the tank post spawn. Eggs will hatch in a few days, and fry will be swimming about a couple days afterwards. The real challenge is feeding them. Hyphessobrycon hexastichos are really small as babies. You'll need to farm infusoria or similar food to get them stuff that is small enough to eat. (There is another article here on the site about just that topic too!)
On the topic of feeding, there aren't many fish that are easier to feed. They'll take just about anything that fits in their mouths. Here we love the Nutramar Freshwater Complete Crumbles, because it offers unparalleled nutrition with a bite size that we can closely control. We also feed a mix of thawed offerings from Gamma that are focused on bite size, like Brine Plus Omega 3, Cyclops, Rotifers, and Tubifex among others.
You know you like Tetras, we all do; gorgeous, active ditherfish, what's not to like? But maybe you've been waiting on finding a small one that looks just a bit different than the Neons, Cardinals and Rummynoses (all rad in their own right.) If so, then Zigzag Tetras might be just the thing! They're gorgeous, super active and basically pacifists. They could be the model citizens for your community tank. Ask your LFS about getting you some from Aquatropic today!