Cryptic diversity is the occurrence of two or more morphologically indistinguishable lineages within a species that are evolutionarily distinct. Tropical rainforests and marine habitats are the most species-rich habitat on Earth and might be where cryptic diversity mostly happens. Within arthropods, recognizing cryptic species is more critical. Limited knowledge of cryptic species in arthropods impacts human health, pest management, and studies of coevolution and species interactions. Ligia species within Arthropoda phylum are halophilic, and their habitat is restricted between the supralittoral area and the waterline of rocky shores all around the world. Worldwide studies on supralittoral Ligia species reveal high levels of cryptic diversity within nominal species. However, for the first time, this study showed cryptic diversity in one terrestrial Ligia species, which lives in the Sierra Nevada de Santa Marta, Colombia. We used two mitochondrial and one nuclear gene and by Bayesian and Maximum Likelihood analyses revealed cryptic diversity in Ligia SNSM. Ligia in the Sierra Nevada de Santa Marta was distributed according to elevation, the first one from 780 to 1,445 MASL, the second one from 1,700 to 1,817 MASL, and the third one from 1,964 to 2,198 MASL. The high cryptic diversity observed in this study for Ligia SNSM emphasizes the high level of biodiversity and endemism in this region. It highlights the importance of conservation studies, efforts, and strategies.
