I finally fully understand the hype about Latin names!

I got a B. Vagans (I'm not sure) about a month and a half ago and I can clearly remember that the enclosure said that it was a Mexican golden red rump. When I asked the owner of the pet shop he said that Mexican golden red rump is just a variation on the common name Mexican red rump and that it is a B. Vagans (the guy that sold it to them put the name on and the pet shop owner said hes never heard of a golden red rump). I took his word for it and I called my spider a B.Vagan the rump was red and at that stage I was happy. Yesterday I did some reading and came across a B.albiceps with a common name Mexican golden red rump . . . CONFUSION!!!! I did some research and some B. Vagans look like B. albiceps and the other way around and my untrained eye is seeing to spiders with different names but they look similar. . .

Is there anyone that can tell me how I can determine what he is? He is in his hole now and think he might be pre-molt so don't want to disturb it for a pic.

He also has the attitude of a pit-bull so I am never to keen on disturbing him....

Found an older pic

A Mexican Golden Redrump is Brachypelma albiceps...

I believe the B sabulosum is now called the B albiceps.

They are quite different due to the fact that the albiceps carapace is a light-tannish colour compared to the vagans black carapace.
But since I haven't seen slings of either, I do not know when this different will become apparent.

Confusion indeed... NEVER, go on common names, simply for this reason.

You are talking about three different species here.

Brachypelma vagans - note the "s" - it's not B vagan. (Mexican Red Rump)
This species have a black carapace and redish abdomen.

Brachypelma albiceps - (Golden Red Rump)
This species have a lite cream carapace with redish abdomen.

Brachypelma sabulosum - (Guatamalan Red Rump)
This species have a brownish carapace with redish abdomen.

You should be able to see post moult.

Thanx guys I will keep an eye on him.