Information on Tropical Freshwater Fish Behaviors

Watching your tropical freshwater fish every day is not only pleasurable, but also lets you see if the fish are getting sick or if there is a problem with the equipment. The sooner the sick fish are treated or the equipment fixed, the more likely the fish will stay alive. The health of the fish and how well the tank equipment is working can be seen in the behavior of the fish.

  1. Baseline

    • Learn all you can about each species of tropical fish you have. Learn where the fish should swim: near the top of the tank, the middle or on the bottom? Species like the betta swim all over the tank, but periodically come to the surface to gulp air. How fast should the fish swim? Some species like the neon tetra normally swim quickly. Is the species bold or does it hide? Some groups of fish like the plecostomus or sucker-mouth catfish prefer to hide during the day and come out in the darkness to feed. Any deviation from this baseline behavior indicates illness, water problems or equipment failure, according to veterinarians David E. Hammett, DVM and Scott Russell, DVM.

    Sickness

    • Abrupt changes in feeding, swimming or body position may indicate problems, according to "Freshwater Aquarium Problem Solver." For example, fish should not constantly hang at the top of the tank, gasping for air. This indicates a water problem. Fish should not constantly swim so rapidly about the tank that they knock against the walls. This could indicate that the tank water is far too hot for the fish to tolerate. Fish should not be scratching their bodies on the gravel or on decorations. This could indicate parasitic infection.

    Prevention

    • Injuries and fish deaths can be preventing by knowing how each species of fish usually behaves. Bottom feeders like the plecostomus often move around decorations in an attempt to feed from the algae growing beneath the decorations. Some fish like tiger barbs will become docile to other species of fish but only if they are in groups of seven or more. Otherwise, they will attack and eat the other fish, according to Fish Channel.

    Types

    • Types of behaviors to watch out for include swimming on the side, not being able to rise from the bottom of the tank, keeping the head down as if balancing on it, swimming in small circles, sudden aggression to other fish or "tail walking," where the fish cannot balance itself to swim properly, according to veterinarians Hammett and Russell.

    Breeding

    • Tropical fish like cichlids often become quite violent when spawning. During spawning, fish may seem to wrestle with their mouths, slap the sides of the bodies together, chase one another about the tank or even attack one another. Spawning behavior is usually a sign that the fish are healthy.