Rummy nose tetras have a silvery, translucent body, a deep red head, and a black and white striped tail. The red color extends into the eye's iris and sometimes beyond the operculum.

Rummy nose tetras can grow up to 2 inches in size, with females being slightly larger.

There are three main species of rummy nose tetras:

• Hemigrammus rhodostomus: The true rummy nose tetra, with a standard red nose and striped tail
• Hemigrammus bleheri: The firehead or brilliant rummy nose tetra, with more redness on the head
• Petitella georgiae: The false rummy, with a black stripe on the tail that extends onto the back half of the body.

Rummy nose tetras are popular aquarium fish that do well in schools of six or more. They are omnivores and will eat most flake foods, but also appreciate live or frozen foods. They prefer water with a neutral pH between 6.5 and 7.5, a temperature range of 24-28°C, and low levels of nitrates.