The metabolism of brevetoxins in shellfish is particularly concerning, as certain derivatives have been shown to remain in the animal over extended periods of time. It has been shown that the main toxin produced by "K. brevis", PbTx-2, is rapidly metabolized, resulting in the production of metabolites that endure in the animal's system for a significantly longer period of time. This stands in contrast to PbTx-3, which is typically eliminated from the shellfish in more or less its original form within a few weeks.