Junior Tetra (Hyphessobrycon robustulus)

Remarks:  The junior tetra (Hyphessobrycon robustulus) is a rare and stunning species of tetra not often seen in the hobby. They start out rather simple with silver bodies and black and white tails, but upon maturity, they become flashes of color. Females develop rounder bodies with yellow fins while males become more streamlined and adorned with vibrant red fins. Some males will even gain a stunning gold iridescence. This sexual dimorphism is rather unique among tetras and make the junior tetra truly stand out.

  While junior tetras are generally hardy, this is only when they are kept in proper water parameters. A good way to achieve the clean, tannin-stained, soft, acidic conditions they prefer is by imitating their natural habitat. In the wild, junior tetras can be found in the upper regions of the Amazon River Basin in Peru. Specifically, they can be found in areas heavily stained with tannins and full of vegetation as well as botanicals such as fallen branches. These calm, warm waters are teeming with organic material as well as small insects and crustaceans for the junior tetra to feed on. If these conditions are imitated, water changes are regular, and a diverse diet high in protein is provided, you will be rewarded with healthy, beautiful fish.

  Due to how small junior tetras are, almost never exceeding 1.5” in length, and their docile disposition, they should only be kept with fish that are peaceful and are not large enough to swallow them. Also, as they are a schooling species, junior tetras should never be kept in groups smaller than 8. Fish that are not kept in proper groups will quickly become skittish and stressed causing them to hide and sometimes even stop eating. So long as these aspects are kept in mind, these rare and unique tetras can make an excellent addition to a peaceful South American community tank or appreciated in a species only tank.