Oh, now this is a really difficult topic for one page. We have hundreds, over a thousand species available to us from a wide diversity of freshwater ecosystems and from all around the world.

Research is key, using reliable resources. Maybe I should list a few:

Practical Fishkeeping: How could I not start here, the magazine helped me massively when I started and the website offers so much. There are articles written by hobbyists, scientists and experts in their field. The Facebook group is of amazing use, it is one of the hubs of the UK and even international aquarium hobby.

Seriously fish: Great for general fishes, some aspects are out of date but will give you the basics for most common fishes. It can cite it’s sources but is written and created by a well known person in the aquarium hobby.

For Catfishes: As a catfish specialist I can more then say this requires a list.

• Planet Catfish: Great for an overview of catfishes itself and it’s blog sections can be really useful. Due to the vastness of the website some topics need further research and some areas might be a little out of date for the time being but it’s amazingly easy to use and useful.
• Catfishes of the World: A very scientific and helpful Facebook group, great for identifying species. The group contains many scientists as well as fishkeepers.
• Catfish Study Group: A society that does have a Facebook group. This society contains many scientists, hobbyists and catfish enthusiasts. They hold UK events.
• Corydoras World: Maybe to consider if really wanting to get enthusiastic about Corydoras as a paid resource but gives extensive guides on their care and breeding.

So what about other fishes?

Loaches.com: Great for a wide selection of different loaches and with many useful blogs and care guides.

Loach Fanatics: Similarly for loaches as the name suggests but can offer catered advise and the Facebook group is run by a well respected expert in loaches.

British Livebearer Association: Definitely a space for livebearers, Poecilidae in general.

Goldfish Care: I’ve had a long connection with goldfish and this group is born out of the ethos goldfish owners should have, half in the ethics and half in the welfare but also both combined.

It is maybe more an art using science and I feel something that can be a little difficult without being given set options. At the end of the day we want what is known as a community, a set of species/fishes that will work together or maybe species only for some. The most important considerations is a large overlap in requiring parameters, similar requirements in water velocity, temperature and behaviour that wont cause conflict.

Behaviour can be the most difficult to predict. Predation is the first behaviour to consider, most fishes are gape limited so limited by the size of their mouth but they might still try. Aim for other inhabitants that do not fit in the other fishes mouth. Aggression is a little bit more difficult to predict and can depend on context, hence research is so important such as a shoaling fish alone might be more aggressive then kept in a group. Busy fish might also cause issues with slower moving fish such as discus.

An important aspect I personally think of when choosing fishes is to consider fast moving fish will outcompete slower moving fishes. It’s worth noticing if food is remaining in time for all fishes to have a good amount to feed on enough.

At the end of the day no article can solve everything it takes research and time, but that is part of the joy in fishkeeping. There is no rush, enjoy the journey not the destination.