Stygobromus t. tenuis is one of only two species of troglobitic amphipods known to occur in the New England physiographic province. The rarity of subterranean organisms in New England is attributed to limited karst development and eradication of organisms from the region during glacial times. Traditionally it has been believed that those troglobitic species presently occurring north of the glacial terminus migrated there following glacial retreat from refugia south of the areas influenced by glacial conditions. However, a few recent studies favour the existence of subsurface refugia in glaciated regions during glacial times. Stygobromus t. tenuis is recorded from springs connected with deep, solution zone aquifers in the Taconic Mountains of western New England, an area well north of the glacial terminus. It is suggested that these aquifers served as a refugium for S. t. tenuis during the latter part of perhaps all of the Pleistocene Epoch.
Smith, Douglas G..
The occurrence of the troglobitic amphipod, Stygobromus tenuis tenuis (Smith) (Crangonyctidae) in the Taconic Mountains of southwestern Massachusetts (USA): a case for the existence of a subterranean refugium in a glaciated region.
International Journal of Speleology,
Available at: https://digitalcommons.usf.edu/ijs/vol14/iss1/4