Most basic attributes of M. laosensis biology, ecology and habitat preferences are unknown, as well as what factors are major threats to Indochinese pearl mussels in this rural part of their range. The Indochinese pearl mussel is of considerable interest because it is the most southern-occurring species in the family Margaritiferidae and because it is presumed to be rare and declining [3, 10]. The majority of stressors to pearl mussel populations originate from economic activity, including the construction of dams and flow regulation [13-18]; road building [19]; felling and ditching of forests [17, 19]; mining [20]; and from urbanization and agriculture [13, 21, 22].The present study represents the first description of the habitat and ecology of M. laosensis. In addition, we describe the major threats and recommended actions for M. laosensis conservation.23].