Testing the utility of DNA barcoding for the rapid assessment of Formicidae biodiversity in the eThekwini region.
Date
2014
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Abstract
The biodiversity of Durban (eThekwini municipality) in KwaZulu Natal is primarily
threatened by urbanization although other factors such as climate change and the spread of
invasive species also pose a significant threat. Knowledge of what species exist within the
city is important for biodiversity surveillance, detecting invasive taxa and uncovering cryptic
species. Conducting a comprehensive biodiversity inventory is a daunting task, especially for
hyperdiverse groups such as terrestrial arthropods, where closely related species can often
only be separated by subtle morphological characters. This study investigated whether the
barcoding marker, Cytochrome Oxidase C Subunit 1 (COI) can be used to efficiently and
accurately delineate species of ants (family Formicidae) in comparison to traditional
taxonomic approaches. The feasibility of DNA barcoding for assembling biodiversity
inventories for urban areas which could be useful in conservation planning was also
evaluated. A total of 619 individuals were sequenced from 23 geographic localities within the
eThekwini region and surrounding regions. DNA barcoding revealed 80 provisional species/
“barcode clusters” or monophyletic lineages which could represent distinct species, while
morphology revealed 51 different morphospecies. Extrapolation measures of species richness
indicated that as many as 153 species of ants could occur in the city. Phylogenetic and
phylogeographic analyses were performed on co-distributed species belonging to the genera
Lepisiota, Camponotus, Pheidole and Pachycondyla to better understand the spatial
distribution of genetic variability in the eThekwini region. Nuclear markers 18S rDNA and
28S rDNA were also sequenced and compared for a subsample of individuals from
Camponotus and Pachycondyla. There was genetic variation at COI and the nuclear markers
for each of the species examined. In order to fully elucidate the population genetic patterns
which could be expected in eThekwini and surrounding regions, further sampling across
more localities is essential. The use of more nuclear markers could also assist in uncovering
these unique patterns of genetic variation in an urban setting. In this study, the utility of COI
as a species diagnostic tool in ants was confirmed. The barcoding library constructed showed
promise in highlighting reserves that should be preserved and possible cryptic speciation for
further investigation.
Description
M. Sc. University of KwaZulu-Natal, Durban 2014.
Keywords
Genetic markers., Cytochrome oxidase., Ants., Formica (Insects), Theses--Genetics.