Blackline Penguinfish

About

The blackline penguinfish (Thayeria boehlkei) is one of those tetras that immediately stands out in a community tank, not just for its looks but for the way it moves. Like all members of the small genus Thayeria, it holds its body at a head-up angle and propels itself with a characteristic hopping motion, the tail dipping slightly with each burst. A thick black stripe runs from the gill cover all the way along the flank and into the lower caudal lobe, which helps distinguish it from its close relative T. obliqua, where that stripe fades well before reaching the head. Originating from river systems in Peru and Brazil, including the upper Amazon basin and the Araguaia River, it is a peaceful schooling fish that does best in groups of at least six, and ideally ten or more. Keeping adequate numbers also tends to curb the occasional fin-nipping that lone or small groups sometimes display. It pairs well with similarly sized South American species like Hemigrammus or Hyphessobrycon tetras, Corydoras, and small Apistogramma, though it fits comfortably into broader community setups too. Breeding is straightforward compared to many tetras, and a single female can be remarkably productive. Overall this is a forgiving, rewarding choice for newer fishkeepers looking for something a little different from the usual tetra lineup.