The shark reef at Mandalay Bay was something we had not seen during our trips to Las Vegas. We thought it may be fun to take our toddlers there. Overall it was much less fun than we expected, especially after waiting in line to pay the admission, which in itself is in my opinion slightly on the high side for what is offered.
It is a short stroll through the dark and tight hallways to see fish you can see in any other aquarium where you can spend hours instead, for a smaller fee. So I would suggest to stay with other attractions on the strip like the Tigers at the Mirage or Circus acts at Circus Circus.

Save your money for a "real" aquarium. We paid almost $60.00 for a family of three and the attraction only takes about 30minutes to go through. It is not worth the money.

It was too short, boring and worth 1/2 the admission price at best.

My husband and I decided to check out the shark reef and were quire pleased with the experience. You do get to see a lot of marine life and the underwater tunnel is especially cool. We didn't bother with the recorded tour guide, but it is available if you want to learn a little. This would be a great place to take kids, but also enjoyable for a young couple like us.