The white film you are seeing is an overproduction of the fish's slime coat due to a crash in pH or infestation of parasites. The bottom sitting is usually consistent with parasites or bacterial infections, but being the skin is milky parasites are definitely suspect. To treat, raise the tank's salt concentration to 0.3% and add an antiparasitic medication to the water.
Either an aquarium or a pond. NO BOWLS, PLEASE!
All goldfish are freshwater.
The same way you spawn any other goldfish.
Fantail goldfish are a hardy breed, strong swimmers and they compete well for food with the ryukin, shubunkin, comet or common goldfish; making these goldfish breeds good tank mates for your fantail goldfish.
Yes, but only for a very short time, for goldfish are known to grow rapidly.
Yes, but it might be better for the fish to have a tank partner by its side. Make sure it is another Fancy Varitey of Goldfish!
Neon tetras, guppies, and bettas are warm water fish(they need a heater) and calico ryukins and shubunkins are cold water(don't need a heater) so none would really fit together except the warm waters. I have a shubunkin goldfish, common goldfish, and 2 dojo/weather loaches in a 29gal, but they used to be in a 10gal. I recommend another double tailed goldfish if you have the ryukin(single tailed will be faster and nip at the others fins and eat all of the food).
Yes, for they are both Fancy Goldfish (It's bad to keep Comets with Fancy varities because most likely the comet will become stressed and die).
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.
the common breeds of goldfish are common, shubunkin, fantail, black moore, orlanda, sarsha comet, comet, ryukin, bubble eye, lion head, rancho, veiltail, celestial, pom pom, and perlscale are the most common.
Goldfish do not get pregnant, but rather they produce eggs. If there is no male around, most often the female will reabsorb the eggs and never actually release any.A female goldfish may get much rounder when full of eggs, but this can be difficult to tell if you have a Ryukin or a Fantail as their body shape is quite round.
There are over 300 different varieties of goldfish and fancy goldfish here is a small list of the most common: Common goldfish Shubunkins Comets Fantail Veiltail Ryukin Globe eye Black moor Telescope eye Lionhead Ranchu Oranda Butterfly Celestial Pompon Hama Nishiki Bubble-eye Pearlscale Nymph Meteor Lionchu