David C. Culver, John R. Holsinger, Daniel J. Feller
Northeastern Naturalist 19 (mo9), 1-42, (1 August 2012) https://doi.org/10.1656/045.019.m901
A number of shallow groundwater habitats that occur in the Coastal Plain and Piedmont of the mid-Atlantic region are documented and described. These isolated tiny aquifers are underlain by clay (hypotelminorheic habitats) and exit at seepage springs, springs, tiled fields and tile drains, and shallow wells. These shallow groundwater habitats harbor species with reduced eyes and pigment that are limited to these habitats. The distribution of 23 such species—four planarians (Sphalloplana and Phagocata), one snail (Fontigens), 13 amphipods (Stygobromus), and five isopods (Caecidotea)—is documented, based on over 450 records. More species (16) were found in hypotelminorheic habitats than in other shallow groundwater habitats. Also, more species were found exclusively in either the Piedmont or Coastal Plain, but seven species were found along the boundary (Fall Line) between these physiographic provinces. Compared to surface waters in nearby habitats, hypotelminorheic water had higher conductivity, higher dissolved oxygen, and slightly lower pH.