Thesis (MSc)--Stellenbosch University, 2010. / ENGLISH ABSTRACT: Opisthopatus cinctipes is a velvet worm endemic to South Africa and is widely distributed in isolated
Afromontane and coastal forest patches throughout the Eastern Cape, KwaZulu-Natal and
Mpumalanga. The species, like most velvet worms is characterized by low vagility, microhabitat
specialization and is hypothesized to harbor significant cryptic diversity. We used partial sequence data
derived from three partial mitochondrial (mtDNA) gene loci (COI, 12S rRNA and 16S rRNA) and a partial
nuclear gene fragment (18S rRNA), as well as gross morphological character analysis and scanning
electron microscopy (SEM) to determine evolutionary relationships amongst a total of 120 specimens of
O. cinctipes from 33 localities. Phylogenetic relationships were investigated using Bayesian inferences,
Maximum Parsimony and Maximum Likelihood analysis. Phylogenetic analysis of mtDNA and nDNA
data revealed the presence of multiple cryptic lineages nested within Opisthopatus cinctipes with at
least nine distinct well supported clades (> 70% / > 0.95 pP), suggesting that the taxon comprises a
“species complex”. Afrotemperate forest specimens were genealogically highly distinct from each other
whilst Indian Ocean Coastal Belt forest (at least in KwaZulu-Natal) specimens were more closely related
and formed a well supported clade. An analyses of molecular variance indicated that (ΦST) 89.31% of
the genetic variation occurred amongst localities. Highly significant FST values were generally observed
across sampled localities (FST = 0.89, p < 0.001). Tajima’s D value was 0.83 over all sampled localities,
implying a decrease in population size and/or balancing selection. Uncorrected pairwise sequence
divergence values between O. cinctipes localities for the COI locus were high and ranged from 3.20% to
19.50%. No haplotypes were shared between localities. There is considerable evidence showing that
past geological events may have shaped the deep genetic divergences observed between sampling
localities suggesting the absence of gene flow. Genetic divergences within the South African O.
cinctipes species complex are shown to have occurred from the onset of the Cenozoic era. The genetic
variation observed within clades was not accompanied by morphological differences suggesting that the
use of morphological characters has grossly underestimated species diversity within South African
Opisthopatus. A robust taxonomic documentation of the species diversity within the O. cinctipes species
complex is critical for the implementation of conservation management plans for this species complex.
We recommend that highly sedentary taxa with limited dispersal abilities and specific habitat
requirements which may be found in sympatry with velvet worms be prioritized for taxonomic revision as they may also harbor cryptic lineages. / AFRIKAANSE OPSOMMING: Geen Afrikaanse opsomming beskikbaar.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:sun/oai:scholar.sun.ac.za:10019.1/4844 |
| Date | 03 1900 |
| Creators | Kunaka, Charlene |
| Contributors | Daniels, S. R., Stellenbosch University. Faculty of Science. Dept. of Botany and Zoology. |
| Publisher | Stellenbosch : Stellenbsoch University |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
| Format | 89 p. : ill. |
| Rights | Stellenbosch University |
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