Population Structure of Denison’s barb, Puntius denisonii (Pisces:udCyprinidae): A Species Complex Endemic to the Western Ghats of India

摘要

Genetic and morphologic variation, haplotype relationships, and structuring of populations within Puntius denisoniiudand its close related species Puntius chalakkudiensis have been tested using molecular and biometric data, to inferudphylogeographic patterns. Sequences of mitochondrial DNA ATPase 8 and 6 genes, and morphometric data, wereudused to find population structuring. Specimens were collected from 7 locations in the southern region of WesternudGhats, a global biodiversity hotspot in India. Biometric analysis revealed apparent heterogeneity in the morphologyudand color pattern between the species at juvenile and adult stages, and among different geographically separatedudpopulations of these species. High values for mean pair wise distances and a high proportion of the total varianceudattributed to differences between the geographically isolated populations with AMOVA, indicated clear populationudstructuring within these species. Extremely high values for Pair wise FST and significantly lower Nm values observedudamong the populations studied, suggested little or no effective gene flow among them. Constructed phylogeniesudfurther confirmed a high degree of population structuring within the species, showing local endemism with populationudspecific haplotypes forming a species complex. The present study thus estimates the validity of subpopulationsudwithin P. denisonii and P. chalakkudiensis; clarifies the relationships of populations of P. denisonii with that of P.udchalakkudiensis, and also indicates the presence of four different independent evolutionary lineages forming crypticudspecies within P. denisonii. The study further emphasizes the need for a conservation policy to be developed for eachudpopulation of both species, separately based on MUs (Management Units).