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Port Elizabeth, South Africa

Branch W.R.,Port Elizabeth Museum | Branch W.R.,Nelson Mandela Metropolitan University | Bayliss J.,University of Cambridge | Tolley K.A.,South African National Biodiversity Institute | Tolley K.A.,Stellenbosch University
Zootaxa | Year: 2014

The taxonomic status of recently discovered populations of pygmy chameleons (Rhampholeon) from the northern Mozambique montane isolates of Mt. Chiperone, Mt. Mabu, Mt. Inago and Mt. Namuli are assessed, and compared with the closest geographical congeners, including Rhampholeon platyceps Günther 1893 from Mt. Mulanje, and Rh. chapmanorum Tilbury 1992 from the Malawi Hills, both in southern Malawi. Relationships were examined using morphological features and a phylogenetic analysis incorporating two mitochondrial and one nuclear marker. The phylogeny showed that each montane isolate contained a distinct, well-supported clade of chameleons. Chameleons from the Mozambican montane isolates are within a monophyletic clade inclusive of species from southern Malawi (Rh. platyceps and Rh. chapmanorum). Although some relationships are unresolved, the southern Malawi and Mozambican isolates appear to share their most recent common ancestor with species from the Eastern Arc Mountains and Southern Highlands of Tanzania and Malawi (Rh. moyeri, Rh. uluguruesis, Rh. nchisiensis). Along with Rh. beraduccii and Rh. acuminatus, all are included in the subgenus Rhinodigitum. Sister to this larger clade are species from west/central Africa (Rh. temporalis, Rh. spectrum) and the Rh. marshalli-gorongosae complex from southwest Mozambique and adjacent Zimbabwe. Morphological and molecular results confirm that Brookesia platyceps carri Loveridge 1953 is a junior subjective synonym of Rhampholeon platyceps Günther 1892. Historical records of Rh. platyceps from the Shire Highlands (Chiromo) and the Zomba Plateau, are incorrect and the species is now considered endemic to the Mulanje massif. All of the four newly discovered, isolated populations are genetically and morphologically distinct, and we take the opportunity to describe each as a new species. Rhampholeon (Rhinodigitum) maspictus sp. nov. is restricted to Mt. Mabu and distinguished by its large size, well-developed dorsal crenulations, and bright male breeding coloration; Rhampholeon (Rhinodigitum) nebulauctor sp. nov. is restricted to Mt. Chiperone and distinguished by its small size, weakly-developed dorsal crenulations, and a large rostral process in males; Rhampholeon (Rhinodigitum) tilburyi sp. nov. is restricted to Mt. Namuli and distinguished by its small size, weakly-developed dorsal crenulations, and prominent flexure of the snout in males; and Rhampholeon (Rhinodigitum) bruessoworum sp. nov. is restricted to Mt. Inago and distinguished by its small size, weakly-developed dorsal crenulations, large rostral process in males, and relatively long tail in both sexes. Copyright © 2014 Magnolia Press. Source

Booth A.J.,Rhodes University | Foulis A.J.,Rhodes University | Smale M.J.,Port Elizabeth Museum | Smale M.J.,Nelson Mandela Metropolitan University
Fishery Bulletin | Year: 2011

This study documents validation of vertebral band-pair formation in spotted gully shark (Triakis megalopterus) with the use of f luorochrome injection and tagging of captive and wild sharks over a 21-year period. Growth and mortality rates of T. megalopterus were also estimated and a demographic analysis of the species was conducted. Of the 23 OTC (oxytetracycline) -marked vertebrae examined (12 from captive and 11 from wild sharks), seven vertebrae (three from captive and four from wild sharks) exhibited chelation of the OTC and f luoresced under ultraviolet light. It was concluded that a single opaque and translucent band pair was deposited annually up to at least 25 years of age, the maximum age recorded. Reader precision was assessed by using an index of average percent error calculated at 5%. No significant differences were found between male and female growth patterns (P>0.05), and von Bertalanffy growth model parameters for combined sexes were estimated to be L∞=1711.07 mm TL, k=0.11/yr and t0= -2.43 yr (n=86). Natural mortality was estimated at 0.17/yr. Age at maturity was estimated at 11 years for males and 15 years for females. Results of the demographic analysis showed that the population, in the absence of fishing mortality, was stable and not significantly different from zero and particularly sensitive to overfishing. At the current age at first capture and natural mortality rate, the fishing mortality rate required to result in negative population growth was low at F>0.004/ yr. Elasticity analysis revealed that juvenile survival was the principal factor in explaining variability in population growth rate. Source

Stanley E.L.,Villanova University | Stanley E.L.,American Museum of Natural History | Bauer A.M.,Villanova University | Jackman T.R.,Villanova University | And 3 more authors.
Molecular Phylogenetics and Evolution | Year: 2011

Girdled lizards (Cordylidae) are sub-Saharan Africa's only endemic squamate family and contain 80 nominal taxa, traditionally divided into four genera: Cordylus, Pseudocordylus, Chamaesaura and Platysaurus. Previous phylogenetic analysis revealed Chamaesaura and Pseudocordylus to be nested within Cordylus, and the former genera were sunk into the later. This taxonomic revision has received limited support due to the study's poor taxon sampling, weakly supported results and possible temporary nomenclatural instability. Our study analyzes three nuclear and three mitochondrial genes from 111 specimens, representing 51 ingroup taxa. Parsimony, likelihood and Bayesian analyses of concatenated and partitioned datasets consistently recovered a comb-like tree with 10, well-supported, monophyletic lineages. Our taxonomic reassessment divides the family into 10 genera, corresponding to these well-supported lineages. Short internodes and low support between the non-platysaur lineages are consistent with a rapid radiation event at the base of the viviparous cordylids. © 2010 Elsevier Inc. Source

Daly R.,Rhodes University | Froneman P.W.,Rhodes University | Smale M.J.,Port Elizabeth Museum | Smale M.J.,Nelson Mandela Metropolitan University
PLoS ONE | Year: 2013

As apex predators, sharks play an important role shaping their respective marine communities through predation and associated risk effects. Understanding the predatory dynamics of sharks within communities is, therefore, necessary to establish effective ecologically based conservation strategies. We employed non-lethal sampling methods to investigate the feeding ecology of bull sharks (Carcharhinus leucas) using stable isotope analysis within a subtropical marine community in the southwest Indian Ocean. The main objectives of this study were to investigate and compare the predatory role that sub-adult and adult bull sharks play within a top predatory teleost fish community. Bull sharks had significantly broader niche widths compared to top predatory teleost assemblages with a wide and relatively enriched range of δ13C values relative to the local marine community. This suggests that bull sharks forage from a more diverse range of δ13C sources over a wider geographical range than the predatory teleost community. Adult bull sharks appeared to exhibit a shift towards consistently higher trophic level prey from an expanded foraging range compared to sub-adults, possibly due to increased mobility linked with size. Although predatory teleost fish are also capable of substantial migrations, bull sharks may have the ability to exploit a more diverse range of habitats and appeared to prey on a wider diversity of larger prey. This suggests that bull sharks play an important predatory role within their respective marine communities and adult sharks in particular may shape and link ecological processes of a variety of marine communities over a broad range. © 2013 Daly et al. Source

Branch W.R.,Port Elizabeth Museum | Branch W.R.,Nelson Mandela Metropolitan University | Tolley K.A.,South African National Biodiversity Institute | Tolley K.A.,Stellenbosch University
African Journal of Herpetology | Year: 2010

Nadzikambia is a monotypic genus described to accommodate the Mulanje chameleon, N. mlanjensis. During herpetological surveys of isolated mountains in Mozambique a population of chameleons was discovered on Mount Mabu. It is referable to the genus Nadzikambia, but features of scalation, colouration and genetic divergence distinguish this population from N. mlanjensis. It is described as a new species, Nadzikambia baylissi, and represents the second species in the genus and the first record of the genus in Mozambique. Notes on reproduction in N. mlanjensis are appended. The discovery of the new species in a mid-altitude evergreen forest remnant on Mount Mabu emphasises the high conservation importance of the region, previously signalled by the discovery of a new species of forest viper (Atheris mabuensis), and a number of undescribed butterflies and freshwater crab species in the region. © 2010 Herpetological Association of Africa. Source

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