The upside down cat first of all - what sort of tank are you thinking of putting it in? With what, how many etc?
The fish usualy sold under this name is
Synodontis nigriventris. The species name is derived from the fact that it's ventral side is light and its dorsal side is dark - the opposite of what most fish are. When it swims upside-down, it has the same counter-shading as a typical fish so its ventral side (which is actualy its dorsal side
) is the darker. It's an african catfish (like the other Synodontis species). They are peaceful and not very picky but they are usualy more active in the night and like to have lots of dark hiding places like rocks and caves to hide in. They benefit from being in a group and are quite peaceful with other tankmates in each other. However, they
can eat very small fish or fry and are also liable to eat small shrimp. As they grow to about 3.5" and can be quite active (though not necessarily while you're watching
), they do need to be in a tank on the larger side - certainly nothing less than a 20 gallon IMO. In terms of feeding, live foods are relished and they'll come to the surface - swimming upside-down - to pick up food. They'll also eat ordinary flake, pellets, frozen foods etc. It would be worth doing a google.com search on this species (use the scientific name) to see what else you might find.
As for the betta and shrimp. It is perfectly likely that this combination would work out (though 1 gallon is small even for a betta so I'd encourage you to upgrade before considering tankmates!). It would depend on the bettas 'personality' though and also somewhat on the shrimp's size. Full grown shrimp won't be eaten because of their size but could still be killed or picked on (I've seen gouramies such as bettas systematicaly pick apart a live shrimp - starting with each leg). Also, it'll need somewhere to hide. Whether the shrimp needs heat or not depend son teh species - like fish, they vary greatly in their requirements. With ghost shrimp, betta temperatures should be fine for it as well (keep in midn that a fluctuating temperature isn't good for your betta so I'd advise getting another heater!). In terms of feeding, it'll pick up any fallen bits of betta food and, if you have any live plants, will take care of any rotting leaves. It'll also eat algae. A site I always enjoy looking at is www.petshrimp.com It has some useful info. on shrimp care - as well as some lovely pictures and information concerning various aquarium shrimp species/varieties.
I basicaly wouldn't reccomend getting any shrimp unless you get a larger tank for your betta (alternatively, get the betta a larger tank and buy some interesting shrimp species - eg: cherries - for the one gallon - a planted shrimp tank looks amazing
). I don't know where or with what you would put the catfish so I won't comment on that yet.
