From garden ponds filled with Koi Carp to the humble goldfish bowl (although goldfish are far happier living in a larger tank) – the UK is a nation of fish lovers.
There are an remarkable five million indoor fish tanks in the UK alone, according to the Pet Food Manufacturers’ Association (PFMA).
That’s about 10 per cent of British households – making fish the third most popular pet after dogs and cats.
It’s a fascinating hobby, particularly for youngsters, and there are few more relaxing activities than watching fish slowly swim around their home.
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There’s plenty of choice when it comes to adding fish to (well prepared and correctly set up) home aquariums, with pet shops offering a bewildering range of colourful and interesting finned friends that will happily live in the corner of your living room.
One of the most important things to note when choosing a new pet fish is whether they are likely to be aggressive - bullying, nipping or even eating their tankmates.
Many fish can co-exist happily with numerous other breeds in so-called community tanks, while others should be kept alone, with other fish of the same breed, or with breeds that are similarly aggressive.
Here are the 18 least, and most, aggressive breeds of popular tropical freshwater fish.
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17. Kuhli Loach
For something a bit unusual, add a few Kuhli Loach to your community tank. These peaceful, eel-like fish thrive in groups and enjoy burrowing in the substrate. They are nocturnal and prefer a well-planted tank with hiding spots. They are excellent at cleaning up leftover food but should be fed sinking pellets to ensure they receive adequate nutrition. | Canva/Getty Images
18. Rummy Nose Tetra
Pretty much all tetras get on well in a community tank and are likely to get on with pretty much anybody - other than the bucktooth tetra which is a bit of a scale-nibbling bully. Add a school of Rummy Nose Tetras though and you'll not have any complaints from the rest of your fishy community. | Canva/Getty Images