Goldfish cannot live in bowls. Fancy goldfish need at least 20 gallons for the first fish, and 10 gallons minimum for any additional goldfish. This means that for two goldfish, the smallest tank you should have is 30 gallons.
Firstly, hopefully you do not have goldfish in the 'goldfish bowl' as they need at least 20 gallons for one goldfish. That being said, you can add sea shells to a tank provided that you have washed the shells clean with one part bleach to 19 parts water (1 cup of bleach to 19 cups of water), rinsed the shells very well in water, then soaked it in treated water (water that you have added Prime or Amquel to for example) before adding them to your tank.
You may want to add a liner to be on the safe side, but you could have 2 fancy goldfish, one one common or single tailed goldfish. (goldfish grow big and fast)
We have two parakeets and we put one bowl in for both. They take turns and one after another will go into to water and splash a bit, peck at it and when they are done neither one goes back in. So, your answer is one bowl for two is ok.
If your goldfish looks like its resting on a place i.e.. an ornament or the ground it means the water that its in has a lack of oxygen. I suggest getting a filter or a bubble blower, if you already have one it may not be working properly or not on enough. You could also put more plants in your aquarium or bowl.
Yes. It should be fine. I have 2 regular goldfish living with a bubble eye goldfish and to fancy fantail goldfish, so I think it will be okay.
the answer is nothing ok
no
Rudd, Orfe, some species of Catfish will all be OK in cold water with Goldfish.
They will all eat one anothers young but adults should get along OK. I do not understand why you would wish to keep wild Rudd in with domesticated Goldfish and Orf though.
i dont no!
That means your fish is ill
Only if you're ok with it dying in a few days. A goldfish needs a minimum of 10 gallons to itself, preferably 20, to allow them for room to grow as well as to account for the amount of waste they produce. They can grow fairly large and are considered messy fish, so they need room and plenty of filtering. A betta fish bowl wouldn't allow for any of those things.