Aquarium fish live in their own Autonomous world. Their behavior does not affect the normal life of the owners, as it happens, for example cats or dogs. Fish happily wagging tail or a gentle purr. But a careful aquarist always on the alert – because inappropriate behavior of fish may indicate some disease .

To determine if the behavior of the fish manifestation of the disease, the aquarist should know what behavior is typical for this species.

The behavior of aquarium fish is usually motivated by instincts, such as the instinct of survival or the instinct of procreation. But the same behavior for different species of fish can mean different actions. So, for example, digging into the ground, a fish can hide from danger, prepare a nest for spawning or disguise itself for hunting for prey.

Your requirements and desires of the aquarium fish Express "sign language" and the different changes of color. There are common signals for all species of fish, and there are inherent only to one particular species or family of fish.

So, if one fish turns to the other and at the same time widely opens the mouth, it shows the "frontal threat". This can mean both an attack and a defense, and in some species - a demonstration of the male before the female during the spawning period.

But if the fish turns sideways and trembles at that the body or tail fin, is a common gesture of courtship in almost all species of fish. But in some species, such a gesture might mean "lateral threat".

If fish ruffling the fins. that is. again, can mean both courtship and threat. Straightening fins, the fish shows how big and bright it is that attracts individuals of the opposite sex, but at the same time it shows other species of fish their abilities.

Many aquariumsfish can change its color. for example, during spawning. Bright coloring helps the individuals of the opposite sex to find each other. Usually fish, colored brightly during spawning, at the rest of the time have a calmer color. This is necessary to either hide from predators, or to hunt for prey.

Some species of fish have a special color when they take care of their offspring. By their coloring, they help the fry to find their parents, and also work as a "distracting maneuver" if a predator is nearby.

The aggressive behavior of fish in the aquarium can be typical not only for piscivorous fish. Fish show aggression when shared or protected areas, when competing for partners for spawning, when they feel danger.

Fish don't attack each other without any reasons.  If you can not immediately identify the culprit of aggression in the aquarium or the causes of this aggression, you should closely monitor the aquarium to find out the motives for this behavior.

Fish that bite off someone else's fins. do not necessarily show aggression. Perhaps the fish took a magnificent fin for something edible. Lightning instinctive reaction does not always give the fish the opportunity to see what it lacks. Therefore, one should carefully approach the selection of fish for the aquarium, not allowing the neighborhood of such species.