No, they can't. Trust me, the terrapin would rip it to shred's.
A tetra likes warm water that is heated to 76-89 degrees Fahrenheit, however a goldfish likes a colder water temperature of at least 70 degrees or lower.
yes it is better to have more than one goldfish in the samke tank. goldfish are VERY social so they like living in groups.
yes
depends, can a ten gallon tank live in a goldfish
Yes
Goldfish should only live with goldfish with the exception of weather (dojo) loaches, bristlenose plecos, or mystery/apple snails.
You should not have goldfish and platies in the same tank ever.
Goldfish are meant to live in cold water, not the warm water in a tropical aquarium. This is a huge reason why goldfish and tropicals shouldn't be in the same tank.
Yes, but your tank size needs to support it. If you mean that a regular goldfish is a long single-tail goldfish, then you need at least a 40 gallon tank just for the 2 fish due to the size potential of the common goldfish. If you mean a regular goldfish as in a round bodied fantail, or perhaps a ryukin, then you need at least a 30 gallon tank for the 2 fish.
as far as i know yes,unless your fish is aggresive
err not a good idear yabbies will eat a goldfish
Goldfish release growth-inhibiting hormones into the water they live in: the more goldfish in a smaller space, the less likely they are to grow. For instance, if I have a common goldfish in a 5 gallon tank, it will grow to about the same size if I had 6 of the same fish in a 30 gallon tank. But leave that fish alone in a 30 gallon tank, and it will grow larger. This is why pond goldfish grow bigger. But goldfish won't grow at all in seawater; they aren't saltwater fish.
they live either in a tank or in the ocean
Yes. A goldfish can live without a filter. They may not live as long, but they do not have to have a filter, or a heater. I had goldfish in a five gallon tank without a filter for a long time. Hope that this helps.
yes, but it may kill the goldfish