1.The hypothelminorheic is a unique superficial subterranean habitat, harbouring troglomorphic species that are unique to this habitat or share species with other subterranean habitats. These species are especially vulnerable to disturbance and human impact.2.The ecological needs of the sympatric Niphargus slovenicus and Niphargus sphagnicolus from central Slovenia were examined in order to assess whether similar conservation strategies could be applied for the two species.3.Their habitat patches appeared to be variable with respect to abiotic factors, and the ecological requirements of the two species differ. A major discriminatory factor is pH.4.The results imply that the conservation strategies for sympatric hypothelminorheic species cannot be generalized; additional research for the case study is discussed. Copyright © 2010 John Wiley & Sons, Ltd.