From garden ponds filled with Koi Carp to the humble goldfish bowl – the UK is a nation of fish lovers.
The Pet Food Manufacturers’ Association (PFMA) say there are an incredible five million indoor fish tanks in Britain.
Around 10 per cent of British households own pet fish – making them the third most popular animal to welcome into our homes after cats and dogs.
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.
One thing you need to be aware of is that some species are naturally more aggressive than others - with some, you might end up waking up in the morning to find you only have one pet left.
Meanwhile, others are totally chilled and happy to mix with others - perfect for so called ‘community tanks’ with a range of species co-existing.
Of course, more aggressive fish can make for fascinating pets too - you just need to be more careful of who you put in their with them
Here are the 18 most - and least - aggressive species of tropical fish.
13. Dwarf Gouramis
Highly prized for their stunning colours, the Dwarf Gouramis only grows up to 2.5 inches in length and will be happy in either hard or soft water - and with any other non-aggressive fish. The South Asian fish breathes directly from the atmosphere so needs easy access to the surface. They will live for up to four years with very little fuss - just make sure to keep their water clean otherwise they may contract diseases. | Canva/Getty Images
14. Harlequin Rasbora
The colourful Harlequin Rasbora is a native of Southeast Asia and is a small and placid fish that will form a dazzling shoal in your aquarium. Get up to 10 of them - they get on well with everyone and eat pretty much anything. | Canva/Getty Images
15. Kuhli Loach
Native to the island of Java in Indonesia, the colourful eel-like Kuhli Loach tend to hide away during the day - coming out in the evening to scavenge food from the bottom of the tank. Thay may not exactly be happy-go-lucky sociable fish, but that doesn't mean they are in any way aggressive. Easy to look after, just make sure they have plenty of hidey-holes to retire to. | Canva/Getty Images
16. Endler's Livebearer
These tiny Guppy-esque fish are simple to breed and even easier to take care of. Their diminuative size means they are a great choice for first-time aquariasts who only have room for a small tank. When you're this small, there's probably not much point in being aggressive - but that's not one of their characteristics in any event. Sociable wee fish, you'll be wanting a small shoal of them. | Canva/Getty Images