| Specimen ID | 1420693 |
| Group | Mollusks-Gastropods |
| Genus | Potamopyrgus |
| Species | antipodarum |
| Common Name | New Zealand mudsnail |
| State | CA |
| County | Contra Costa |
| Locality | Tributary of Walnut Creek approx. 500m East of SR 242 |
| Mapping Accuracy | Accurate |
| HUC8 Name | Suisun Bay |
| HUC8 Number | 18050001 |
| HUC10 Name | Walnut Creek-Frontal Suisin Bay Estuaries |
| HUC10 Number | 1805000102 |
| HUC12 Name | Walnut Creek-Frontal Suisin Bay Estuaries |
| HUC12 Number | 180500010204 |
| Map | |
| Collection Day | 17 |
| Collection Month | 5 |
| Collection Year | 2017 |
| Year Accuracy | Actual |
| Potential Pathway | hitch hiker with stocked fish | hitch hiker on small watercraft |
| Status | established |
| Comments | 64 individuals found in 600-organism subcount from bioassessment sample ID 207R01591 collected using State of CA SWAMP protocol for benthic macroinvertebrates |
| Record Type | NAS sighting report |
| Verifier | BioAssessment Services |
| Freshwater/Marine | Freshwater |
| Number Collected | 64 |
