When publishing a new dataset on plankton the occurrence records with scientificName = subphylum Crustacea are interpreted as a (flagged doubtful) genus Crustacea. See subphylum Crustacea, urn:lsid ...
Crustaceans (Crustacea /krʌˈsteɪʃə/) form a large, diverse arthropod taxon which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill ...