Fish That Hang Vertically

The vast majority of fish swim oriented horizontally. However, some species have adopted a vertical body orientation for a number of reasons. Some fish use this position to hunt for food among the substrate. Others use this posture to camouflage themselves. A variety of freshwater and saltwater fish use this unusual type of swimming.

  1. Shrimpfish

    • Shrimpfish have vaguely razor-shaped bodies and swim vertically in schools. They usually feed on tiny crustaceans swimming on the substrate. Their unusual posture also helps camouflage them from predators. In aquariums, their care is similar to their close relatives the seahorses. Shrimpfish need to be kept in a group and in an aquarium with very little water movement and no fast-swimming or aggressive tank mates.

    Headstanders

    • Headstanders are freshwater fish found in the Amazon drainage. They belong to the tetra family, a diverse group of fishes that includes the diminutive neon tetra and the infamous piranha. This group includes two similar families of fish. They generally go back and forth between a horizontal and vertical body orientation, "headstanding" for prolonged periods to feed and camouflage themselves. In the aquarium, they need peaceful tank mates of a similar size and soft, acidic water.

    Seahorses

    • Seahorses have a very different body shape from most fish, complete with vertical bodies. In fact, they were once believed to be insects, not true fish since they have such unusual anatomy. In aquariums, they need very specialized care. This includes daily feedings of small, live shrimp -- though some may inconsistently accept dead foods. They need a small aquarium, with very little current. Few fish can share a tank with seahorses without out-competing them for food.

    Bay Pipefish

    • Bay pipefish have thin, eel-like bodies. They hang vertically near sea grass and sway their bodies wit the current. Using prehensile tails, they usually secure themselves to the grass while they feed on tiny crustaceans. Their greenish bodies closely resemble sea grass, providing camouflage from predators.

    Other Fish

    • Many other fish may also swim vertically. However, it can often be a sign of a serious disease. Fish with damage to their swim bladders may swim at odd angles, including vertically. The swim bladder may be damages by infection, fighting or poor water quality. In some case, it may heal on its own, but in many, the damage can be permanent.