The penguin tetra is a lovely fish that comes from many places in the Amazon River drainage throughout South America. Virtually all of the penguin tetras you will find in the hobby nowadays have been commercially farmed in either Florida or the Far East, although they sometimes are offered on list of importers of South American fish. We will leave it to the splitters and lumpers among ichthyologists to decide whether the fish we keep in our tanks are Thayeria boehlkei or Thayeria oblique, as the farmed penguin tetras are most probably a mixture of the two species – assuming that they are two distinct species. Swimming at a nose up angle, penguin tetras do best in groups of six or more of their own kind. These fish also were/are referred to as “hockey stick tetras” which is, to me, a more descriptive name for them than penguin tetras. For some reason, the hockey stick common name never was very popular, and they are now universally known as the penguin tetras.
Penguin tetras make a wonderful addition to any tank of community fishes. They are large enough not to be bothered by most other fish, and they will never do any harm to any of their tankmates. While the wild fish come from somewhat soft and acid water, all of the farmed fish we see in the hobby today will do very well in a pH around neutral (7.0) and with soft to moderately hard water. They can be a little skitterish, and besides doing best in schools of their brethren they prefer a densely planted aquarium, and moderate light levels. They will thrive on any foods that are fed to a community tank, but they especially enjoy small critters such as brine shrimp or daphnia. They can be kept on a diet 100% of dried prepared foods.
This fish is not bred that often by hobbyists. They spawn easily like any other characin/tetra, but the babies are very tiny for the first week after they become free-swimming, and can be very difficult to feed. .