Aquarium population question

[KaidatheDragon]

I recently acquired a 50 gallon fish tank. I have a few fish in it and I was wondering if that’s too much to get more fish…
4 Freshwater Fiddler Crabs
5 Long Fined Zebra Danio
2 Neon Tetras (giving to a new home due to the small amount of them and my catfish possibly eating them)
1 Dragon Goby (I know it’s a Brackish fish…)
1 Pictus Catfish
I was thinking about getting some more catfish so the one inside isn’t as lonely, how many should I get and should I with the population now? And what is nice good fish to fill the tank more and make it look nice if I can. And I have a betta in my old 5 gallon right now due to possible aggression to the fish since it was having issues to the neons in the previous tank.
Please help

[Carylnz]

50 US or Imp gallons? I am assuming the tank is approx 4ft?
I know nothing about fiddler crabs but wonder if they are eating the neons, although the pictus may be the culprit as well.
Pictus are very territorial so stick with one. You could get another but you will need lots of space for them to move with plenty of hidey holes and be prepared for them to fight over the hiding spaces!
As pictus keep more to the bottom strata, when feeding, consider some mid to top dwellers - large enough not to fit in a pictus' mouth. Pictus can get to all the food before other fish as they are very fast so do not get slower moving species.