Males how very tiny white pin head dots along the front of their two front fins and all over their gills, if they are large fish its quiet obvious, but if small it is best to have a magnifying glass... Females in season they have swollen genitals near their bottom fin that are just before their tail. It is hard to tell with females, if they are not in season you can not tell their gender as they are males that aren't ready to breed, or they are females that aren't in season. Even if they are in season it is still quite difficult to tell if they are showing. so you can see that's why most pet shops tell you, that they cant tell the difference as it is too hard and difficult.
Yes, but only for a very short time, for goldfish are known to grow rapidly.
If the cat has orange and black/gray, it is most likely to be female. That is because the combination of the orange with black/gray is sex linked to females. It is the same story with calico cats--they are always female.
Not necessarily. A calico cat is only female, due to genetics, while all tabby cats are males. A calico is typically white with orange and black patches in its pelt. Well that is not quite true. Most tabby cats are male and most calicos and tortoiseshells are females, but not all of them. They are very rare, but they do exist. Also, calicos of any gender must be orange, white, and black, or ginger, cream, and gray, in distinct patches.
the gender is a guy you can tell
A calico quilt is a quilt made out of calico fabric.
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).
This color is almost always female. This red and black color in cats in on the X chromosomes. Since females have two X's, they can have red and black in their coats. The white in calico is a marking over the other two colors. The best way to say this is " tortoiseshell and white". Males (XY) can be calico only if they have a genetic abnormality such as XXY.
no animals live in calico because calico is a type of fabric
Yes, calico cats start out their lives as calico kittens.
Either an aquarium or a pond. NO BOWLS, PLEASE!
All goldfish are freshwater.
No, there is no such thing as a miniature calico cat. Calico cats are not actually a breed, calico describes their color.