Amazonian puffers are quite peaceful. I was able to keep a few in my planted tank (1450cm 45cm 45cm) with various species of tetras and plants. They were there mainly for small snail control. The problem I see is that all Colomesus assellus I've seen for sale were under 5 cm. Even if you wait for it to grow to 10 cm (highly unlikely), the Senegal would quickly outgrow the puffer. The biggest Senegal I had was a wild specimen that was imported from japan that was 45 centimeters. Wild ones grow to a bigger size, but even cb Senegals will easily reach 30 cm in no time. Senegals, imo, have the biggest personalities and an appetite to match, so i strongly suggest against mixing the two.
Hey,
I was just thinking about the growth rate of these two species, as well.
I got a group of 3 birchirs now, each about 6cm long.
A pet store in my area will get a C. assellus next week and if it's not extremely small I may consider taking the risk. If I get the feeling the bichirs consider him as a prey I can easily separate them as I got 2 more tanks which aren't currently in use.
So I might actually take the risk but I will definitely keep an eye out for the puffer!
Hey, just a little update.
I changed my mind and decided not to add C. assellus to my tank.
It's a risky combination and the obvious issues you may face when keeping this puffer i.e. teeth growth or constant swimming up and down the aquarium glass made me rethink my original plans.