DNA barcoding of the mesic adapted striped mouse, Rhabdomys dilectus in the Eastern Cape and KwaZulu-Natal provinces of South Africa

Abstract

South African small mammals are under-represented in DNA barcoding efforts, particularly from the eastern forested regions of the country. This study reports DNA barcoding of Rhabdomys taxa from previously unsampled parts of the Eastern Cape and KwaZulu-Natal provinces of South Africa. The complete mitochondrial DNA cytochrome oxidase I (COI) gene was sequenced for 101 Rhabdomys sp. individuals from 16 localities from all three main forest groups (coastal, mistbelt, and scarp forests). Molecular data were supplemented with external morphological measurements, including those deemed potential taxonomically diagnostic characters. Findings indicate the area to be inhabited solely by Rhabdomys dilectus chakae. Haplotypes distributed across the three forest groups were separated by shallow sequence divergences ranging from 0.001–0.015 (Kimura 2-parameter model) and displayed very little population genetic structure (FST= 0.071787). Morphological data revealed some regional metric differences in external morphology, but all the head-and-body to tail (HB: tail) ratios match that of R. d. chakae, and consequently, molecular and morphological data are congruent. These data confirm a range extension of R. d. chakae, supporting the utility of COI barcodes in the identification of small mammalian species.

DNA barcoding reveals cryptic diversification and taxonomic discordance among bats and birds within sub-Saharan Africa

“…Most other noteworthy regional divergences occurred within biodiversity hotspots over eastern Africa (three bat species, Figure 3c; four bird species, Figure 4c) and south-eastern Africa (three bat species, Figure 3d; three bird species, Figure 4d). Sample bias and taxonomic/database errors notwithstanding, this suggests heightened cryptic bat and bird speciation in these regions, where hidden insectivore and rodent diversity is already apparent (Demos et al, 2014;Matamba et al, 2020Matamba et al, , 2021. Altogether, cryptic divergences among the bats and birds assessed frequently mapped onto Afrotropical paleoclimatic mammalian and avian refugia (Levinsky et al, 2013;Mizerovská et al, 2019); some of the avian refugia having persisted since the Eocene (Fjeldså & Bowie, 2008).…”