any member of the subphylum Crustacea (phylum Arthropoda), a group of invertebrate animals consisting of some 45,000 species distributed worldwide. Crabs, lobsters, shrimps, and wood lice are among the best-known crustaceans, but the group also includes an enormous variety of other forms without popular names.
It is thought that infrequent, low-dose users may test positive for Xanax within urine for up to 4 days post-ingestion. Frequent, high-dose users of the drug may test positive for Xanax after a full week post-ingestion via a urinalysis. Results from a urinalysis can be confirmed with technology such as GC/MS.
Depending on the dosage, it can be detected up to 5 days after the last dose. A single 0.5mg dose may not be detectable after say 3 days. But urine tests look for metabolites of a drug. In the case of Xanax, the metabolite is Î±- hydroxyalprazolam, which has the same half-life as xanax itself. If you are taking an Extended-Release version of it, then it may be in a your system for a bit longer.