Pygmy Hatchetfish

About

Found in the Amazon River basin of Peru, the pygmy hatchetfish Carnegiella myersi is the smallest member of the hatchetfish family and arguably its most delicate. That immediately recognizable deep-keeled body profile is slightly more elongate here than in related species, the result of a shallower rounded keel, and the coloration runs to basic silver decorated with scattered dots, dashes, or fine lines along the lower body. Like its cousins, this fish hugs the surface film almost exclusively. You will rarely see it anywhere else in the water column. The jump is real: leave a gap in the lid overnight and you may find fish on the floor by morning, so a tight cover is non-negotiable. Interestingly, research using high-speed video has shown that the famous "powered flight" attributed to hatchetfishes is a myth. The pectoral fins launch the fish out of the water but provide no propulsion in the air. It is simply a powerful, energy-costly escape jump. Because of its small size and timid disposition, Carnegiella myersi is not well suited to a busy community. Calm, similarly-sized tankmates like small characids or dwarf catfishes are a much better fit. Keep a group of at least six, ideally more. They do noticeably better with numbers around them.