This is the Ed Hardy Swarvoski-studded bikini worn by world-famous adult star, Gianna Michaels in her portrayal of a very unfortunate victim.
The actress wears this skimpy bikini during the scene where her bikini top memorably slips down as she skims across the surface of the lake whilst parasailing.
Attacked by the ravenous piranha, her lifeless body lifts back up into the air exposing her gory demise.

The bikini displays wear from use which include pulled and stretched stitching along the seams of the bikini bottoms.
An instantly recognisable costume from another great attack sequence.