You dont have to, unless you are keeping it with the opposite sex.
Female guinea pigs only need to be spayed if they are going to have contact with an unaltered male guinea pig.
You don't need to spay female guinea pigs, but they will be healthier in the end of their lives if you do.
If by "castrated" you mean "neutered" like a cat or dog, you'll have to ask a vet that is experienced with exotics (guinea pigs are considered "exotics" in the vet world). Keep in mind that neutering a male guinea pig will prevent him from impregnating females, but will not change his aggression toward other males if he has any.
No,some male guinea pigs actually help clean and care for babies
No
Male Guinea Pigs are called Boars, female Guinea Pigs are called Sows, and babby Guinea Pigs are called Pups. A group of Guinea Pigs is called a Herd. :)
not particularly, there are many female and male guinea pigs
The main difference between male and female guinea pigs is the genitalia. Both male and female guinea pigs have six nipples and fur on their abdomen. By the way, in case you didn't know, male guinea pigs are called "boars" and female guinea pigs are called "sows".
pigs that are castrated. :DD
It's is same for guinea pigs and normal pigs. Bore is male and Sow is Female.
Male guinea pigs only fight when they are trying to be the leader of there herd, there is always a dominate piggy in the herd.
In general male guinea pigs are more aggressive than female guinea pigs, however, male guinea pigs also tend to be more outgoing and friendlier than females.
No.
I think male guinea pigs are called boars. Or if you want a name for one i called mine Neo.