danny boy said:one important thing you should know that every body has missed is that you should never buy any fish without first researching what it is you are buying.. this is very important especially if you have a small tank and other fish already in there. i cant stress this point enough.
Proided that the fish that you are getting
1: have any info available
2: the person you are getting them from knows anything about them
3: You have the option
The whole reason that I have my fish is that my roomate left them there when he moved out, so i just jumped into the hobby and It has all worked out for the better. At least they are doing the research early, that way you can learn and not at the expence of your fish. The real people to gripe at are the ones that keep getting fish, having them die and always wonder why. But rather then reading about it just go out and get more fish.
I don't want to sound like a jerk. That is just my saop box. When I first started out I was told by a lady that I had no business keeping my fish, because I had 6 in an 18 gal. she never stopped to ask to see that they were all less then 3 in. and were top and bottom dwellers. Then she proceded to tell me that my Violet goby's natural life cycle was to be born in fresh water, move to brackish and when it reached adulthood would swim out to the ocean and then return to spawn... (it doesn't)