After years of extensive biological research, scientists identified at least 11 species new to science occupying the ruggedly divided limestone formations of the Battambang and Stung Treng regions in Cambodia. The researchers describe these remote, isolated outcroppings of limestone as ‘evolutionary laboratories,’ where organisms have evolved for millions of years independently of each other. Among the discoveries reported by Fauna & Flora were a stunning turquoise pit viper and an extremely small land-based snail. This important finding is a result of the increasing pressures these unique rock habitats are being subjected to from limestone mining and habitat fragmentation. The discoveries serve as a reminder of urgent, global challenges related to protecting and documenting Cambodia’s subterranean biodiversity before it is destroyed through limestone quarrying.
New species discovered in Cambodia’s rare rocky ecosystems
The identification of 11 previously unknown animal species within Cambodia’s karst ecosystem (the limestone hills and their associated limestone plateau or cave system found in the provinces of Battambang and Stung Treng) is a huge step towards contributing to biodiversity in Southeast Asia. Since the karst ranges are essentially surrounded by large areas of flat terrain that have been altered by humans, these rocky ecosystems represent an isolated form of biological island with all the isolating surroundings serving to protect the new species from existing populations and thus represent a ‘isolated habitat’ in which species may continue to evolve independently.
Three-year survey of 64 caves unveils hidden biodiversity
According to conservationists from Fauna & Flora, these rocky habitats provided the perfect opportunity for animals to develop highly specialised adaptations that set them apart from other species globally; therefore, there are considerable numbers of species, which represent a ‘treasure’ of biodiversity known only to the local communities until now. In total, 64 caves have been appraised through three years of study within these rocky ecosystems across a total of ten mountain ranges or mountains.
Micro-fauna and rare reptiles found in the caves
The biological diversity noted in this study encompasses numerous distinct classes of faunal organisms; thus, illustrating the complexity which exists within cave-dwelling forms of life. Highlights of interest include one newly discovered turquoise colored pit viper (Trimeresurus sp. nov.) at the Phnom Prampi Natural Heritage Site and the discovery of Clostophis udayaditinus (a terrestrial ‘micro-snail’) with a maximum size of 2 millimetres (i.e., this is the first recorded occurrence within the borders of Cambodia), as well as the discovery of 3 new species of millipedes – implying that there are diverse evolutionary paths represented by even the smallest invertebrates found in these caves.
Isolated evolution in Cambodia’s limestone caves
The ‘island effect’ produced by karst topography is the main driver of high levels of endemism in these areas. According to a biological expert like Dr Lee Grismer from La Sierra University, limestone formations can be viewed as unique laboratories where the only locations where you’ll find an organism are through an individual cave or cave system and nowhere else on Earth. That means that if a certain mountain where a certain animal is found were to be destroyed, it could lead to the total extinction of that animal. According to Fauna & Flora, these creatures are effectively ‘trapped’ by a sea of inhospitable, human-made landscapes. Over millions of years, they have continued to evolve in complete isolation within these evolutionary islands.