Hydroisotoma schaefferi
- kingdom: Animalia
- phylum: Arthropoda
- class: Entognatha
- order: Collembola
- family: Isotomidae
- genus: Hydroisotoma
- species: Hydroisotoma schaefferi
Paxton- West Concord
Massachusetts- East Brunswick
- South River
New Jersey- Tannersville
Pennsylvania
United States