Efficacy of Cryptic rodents and challenges for conservation in Africa: A review

Cryptic species are unique species that are genetically divergent, although formerly nominated as a single species because of their morphological indistinguishability. In the last 20 years, it has been widely documented as a cryptic species in scientific articles and has nearly consistently dispersed across all taxa and ecological niches. Unfortunately, the inconsistency of cryptic species' descriptions and taxonomic classification makes it difficult to quantify and understand their coevolutionary relevance and ecological questions. We aim to review the cryptic rodent species, discuss the mechanisms to describe them, the reasons how diversified, and assess their challenges for conservation. From a limited review of the literature, we found significant numbers of cryptic putative rodent species on the African continent. Methodological error, evolution processes, mutation, speciation, morphological homology, and convergence might be associated with cryptic species. Our regression analysis shows that cryptic species are distributed almost evenly across almost all rodent families in almost all countries. The scatterplot analysis indicates cryptic diversity has a linear scale associated with the number of publications and time. Our result shows articles emphasized the importance of molecular, morphological, cytogenetic, and ecological niche approaches in understanding crypticity. An integrated approach is more appropriate to recognize and decode the notions of cryptic nature, notably for divers' small mammals, rather than using single methods. Understanding cryptic species is crucial for exact biodiversity estimation and conservation, including endemic and endangered species.