Aggression in Fish

Following are reasons for aggression in aquarium fish-

• Most aggression in the aquarium occurs over territory. Certain types of fish want to create and keep their own territory, once you introduce an aggressive fish to your aquarium it will attach itself to a particular section of the fish tank and not allow others near.
• Some fish will always compete for food. An aggressive fish will fight off other fish for food.
• Aggression in fish can be increased by the effect of growth hormone. It increases the metabolic demands in Species resulting in aggression to fight for daily needs.
• In many cases, fish become overly aggressive when the Tank is overstocked.
• Lack of cover and tanks which are too bare can result in aggressive behaviors when fish feel they are too exposed to predators.

Types of Aggression

There are mainly two main types of aggression.

Territorial Defense

Territorial behavior is exhibited to defend Resources. Fish do not defend a territory for its own sake. They defend territories for the following reasons-

• Protection from predators.
• Availability of food.

Social Ranking

Social ranking behavior is exhibited for mate selection. Social ranking is an important behavior in many animals, including fish. It is necessary to determine which individuals are the most capable of survival, and therefore breeding potential.

How do you deal with Aggressive Fish in an Aquarium?

• Separate your passive fish, you will have to separate your aggressive fish from the ones they are attacking.
• If your fish are too aggressive to handle, you need to set up a fish jail in your aquarium. This makeshift jail will allow the bully to see and smell the other fish, but not attack them. It will help them get used to each other's presence. You can buy a product that can create this jail by this product on Amazon.
• Add new hiding spots in your aquarium. Some fish are too passive and can be easily bullied and hurt by aggressive and territorial fish. You need to add new decorations so that fish species can act as new hiding spots and protect them from the aggressors.

Why is Fish being Aggressive?

Following are reasons why some fish species are aggressive - 

The most common causes of aggression are lack of space, Incompatible Tankmates, poor water conditions, and feeding issues.

Fighting for food

Some fish will always compete for food, they become aggressive at feeding time.

Territory marking

Certain types of fish want to create and keep their own territory, once you introduce an aggressive fish to your aquarium, it will attach itself to a particular section or the fish tank and not allow others near.

Fish size

Larger fish may take advantage of their size and fight smaller ones. When you pick your fish, always consider species that are likely to grow at the same rate.

Some fish can become aggressive when they are sick. In many cases, fish become more aggressive when the tank is overstocked.

What are the signs of Aggression in Fish? 

Following signs of aggression in fish- 

• Changes in behavior among fish.
• Changes in the territory.
• Chasing another fish around the tank.
• Split fins.

Why are some Fish Aggressive?

Aggressive behavior can derive in fish species due to territory, sex-specific selection and genetic variation are some of the reasons. Aggression in fish can be increased by the effect of growth hormone. It increases the metabolic demands in species resulting in aggression to fight for daily needs.