Which type of fish is the least aggressive?

It's impossible to say definitively which fish is the *least* aggressive, as aggression varies widely even within species based on factors like individual temperament, tank environment, and social dynamics.

However, some fish species are generally known for their peaceful nature and are often considered good choices for beginner aquarists:

* Tetras: These schooling fish are known for their peaceful demeanor and vibrant colors.

* Danios: Another schooling fish, Danios are active and playful, adding energy to any tank.

* Rasboras: These small, peaceful fish are great for community tanks.

* Guppies: These livebearers are known for their vibrant colors and peaceful nature.

* Corydoras Catfish: These bottom-dwelling fish are peaceful and help keep the tank clean.

* Rainbow Fish: These beautiful fish are generally peaceful and can be kept in groups.

* Platies: These livebearers are peaceful and easy to care for.

* Mollies: Another livebearer species, Mollies are known for their peaceful nature.

Important Considerations:

* Tank Size: Smaller tanks can lead to more aggression as fish have less space to spread out.

* Species Compatibility: Even peaceful fish can be aggressive towards certain species, so research compatibility before mixing fish.

* Individual Variation: Even within a peaceful species, there can be variation in temperament.

Always research the specific fish species you are interested in and consider their individual needs before adding them to your tank.