Print PageUnderstanding patterns of biodiversity depend on accurate assessment of species richness. Increasingly, cryptic speciation is being detected in morphologically described zooplankton species. Epiphanes senta (Monogononta) had been considered a cosmopolitan species in the past due to their apparent worldwide distribution. Recent studies using DNA sequence comparison, morphology, and behavior have shown that there are at least 3 different species within the Epiphanes senta complex – E. ukera, E. hawaiiensis and E. chihuahuaensis. Previous work also showed that two distinct genetic lineages of E. chihuahuaensis co-occur in temporary rock pools in the Northern Chihuahuan desert. Here we investigate potential cryptic speciation among populations in this region using haplotype analysis of cytochrome c oxidase 1 (CO1) as well as phylogenetic analyses based on the ITS (internal transcribed spacer region) and MT CO1 sequences.
Results/Conclusions
We collected individuals from two sites near El Paso, TX (Rio Bosque Wetland Park – two wetland cells; Hueco Tanks State Park & Historic Site [HTSPHS] – three rock pools). Additional samples will be obtained from ponds from Big Bend National Park, TX. Clonal lineages were obtained from single females and cultured. DNA was extracted from 8-20 individuals. If new diverging lineages are found within E. chihuahuaensis we can conclude that diversity in the E. senta complex is much greater than previously believed. In addition, this would indicate that these populations have been genetically isolated and that differentiation can occur even in a relatively close geographic area or that there is recurrent colonization by new genotypes. Additional ecological and morphological studies are needed, to fully understand how this genetic diversity impacts community function and structure.
