Publications by authors named "Gouws G"

Atractoscion macrolepis was described as a species separate to A. aequidens, distinguished by a geographically-separated distribution, genetic evidence and a diagnostic meristic character: the number of pored lateral line scales. However, the distinction of these species and description of A.

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A large portion of the pipe infrastructure used in the chemical processing industry is susceptible to corrosion under insulation (CUI). Eddy current-based magnetic sensing is one of the methods that can be used as an early detector of this corrosion. However, the large sensor-to-pipe distances used in this method, due to the presence of insulation, limits the sensitivity to corrosion.

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A new species of freshwater crab, , is described from the Winterberg-Amathole mountain range in the Eastern Cape Province, South Africa. Morphologically, Peer & Gouws, most closely resembles but can be distinguished by key morphological characters including the variation in the shape of the subterminal segment of gonopod 2 between both species. Genetically, Peer & Gouws, is placed within the clade of small-bodied, mountain-dwelling crabs including , , , , , and .

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Lethrinus nebulosus (Forsskl, 1775) is distributed throughout the Indian Ocean, Indonesia and the West-central Pacific. Given recent evidence suggesting two cryptic species of L. nebulosus in the southwestern Indian Ocean, we implemented a multispecies coalescent approach using nuclear and mitochondrial DNA loci and conducted Bayesian tests of species delimitation.

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Microelectrodes are commonly used in electrochemical analysis and biological sensing applications owing to their miniaturised dimensions. It is often desirable to improve the performance of microelectrodes by reducing their electrochemical impedance for increasing the signal-to-noise of the recorded signals. One successful route is to incorporate nanomaterials directly onto microelectrodes; however, it is essential that these fabrication routes are simple and repeatable.

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A new species of threadfin bream, Nemipterus elaine, from the Western Indian Ocean is described. The new species is known so far only from off the coast of southern Mozambique, and appears most closely related morphologically and genetically to N. randalli Russell, 1986, but differs in having shorter pectoral and pelvic fins, and the upper caudal lobe produced to form a short, bright yellow filament (a long red trailing filament present in N.

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Typically, NMR systems are bulky and expensive laboratory based equipment. For half a century after its scientific discovery taking NMR outside of a laboratory environment is still not a common practice due to the complexity of the underlining physical phenomena and its low sensitivity, to the myriad of technical challenges when integrating a complete system. The scarcity of compact and mobile NMR systems has prevented its proliferation into many other areas and applications.

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The taxonomic status of the widely distributed Indo-Pacific undulated moray eel, Gymnothorax undulatus, is revised using morphological and genetics features. Ninety-seven specimens previously identified as G. undulatus were examined and their mitochondrial COI and 16S rRNA genes were analysed.

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The highly diverse goatfish genus Upeneus (Mullidae) requires enhanced attention regarding the possible occurrence of undescribed species in insufficiently explored regions. This study focuses on the South-Western Indian Ocean region (SWIO), and on the so-called japonicus-group, a taxonomic species group of Upeneus. Based on in-situ observations and collections in Sodwana Bay, KwaZulu-Natal, South Africa, the Floros goatfish, U.

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Patterns of genetic structure and connectivity of the monotypic cigar wrasse within western Indian Ocean (WIO) are poorly understood. Whether the species exists as a single panmictic population across the WIO is unclear. Sequence data were generated from two mitochondrial genes (cytochrome and ATPase 6) and one nuclear intron (S7 intron I).

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The geographic occurrence of moggel Labeo umbratus × mud fish Labeo capensis hybrids and the threat of hybridisation to the genetic integrity of L. umbratus were investigated. Genetic evidence from mtDNA cytb and nDNA s7 intron sequence data indicated probable interspecific hybridisation in two impoundments, Hardap Dam (Orange River Basin, Namibia) and Darlington Dam (Sundays River Basin, Eastern Cape, South Africa).

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A critical part of the sexual selection process in animals is the genetic mating system. Quantifying mating systems, especially in species with cryptic life histories can be challenging. One approach is to use genotypic markers and accurate parentage analysis, along with methods to account for bias when sampling natural populations, to calculate sexual selection metrics derived from Bateman's principles.

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Coral reef health and biodiversity is under threat worldwide due to rapid climate change. However, much of the inter- and intra-specific diversity of coral reefs are undescribed even in well studied taxa such as fish. Delimiting previously unrecognised diversity is important for understanding the processes that generate and sustain biodiversity in coral reef ecosystems and informing strategies for their conservation and management.

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A new species of hermit crab, Pagurus fraserorum n. sp. (family Paguridae) is described from rocky subtidal reefs off KwaZulu-Natal, South Africa, and illustrated using both conventional drawings and colour photographs, and via three-dimensional (3D) X-ray micro-computed tomography (μCT).

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The first record of the straptail fish, genus Macruronus, from South Africa was based on a single specimen captured off the Atlantic Cape coast and described as a new species, M. capensis Davies 1950. Davies did not examine specimens of the other extant nominal species in the genus, but based his conclusions solely on references to the original descriptions of M.

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Analysis of genetic variation can provide insights into ecological and evolutionary diversification which, for commercially harvested species, can also be relevant to the implementation of spatial management strategies and sustainability. In comparison with other marine biodiversity hot spots, there has been less genetic research on the fauna of the southwest Indian Ocean (SWIO). This is epitomized by the lack of information for lethrinid fish, which support socioeconomically important fisheries in the region.

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A measurement of the complex permittivity, ε, of a liquid can give valuable information about the molecular polarizability and dielectric losses. This can be obtained by means of an impedance measurement using a parallel plate test cell. However, highly accurate and precise measurements are challenging, in particular when measuring as a function of temperature.

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A 20 MHz Class D amplifier with an output of 100 W of RF power has been developed. The compact size printed circuit board area of 50 cm and efficiency of 73% make it suitable for mobile nuclear magnetic resonance (NMR) systems. Test results show that the rise and ring down times of the amplifier are less than 0.

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A new species of freshwater crab, , is described from the southern region of the KwaZulu-Natal Province, South Africa. most closely resembles which is re-described here, but can be distinguished by a suite of key morphological characters including carapace shape and width, slim pereopods, inflated propodi of the chelipeds, and the shape and terminal segment length:subterminal segment length ratio of the 1 gonopod. In a previous study (Gouws et al.

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Interdigitated dielectrometry sensors (IDS) are capacitive sensors investigated to precisely measure the relative permittivity ( ϵ r ) of insulating liquids. Such liquids used in the power industry exhibit a change in ϵ r as they degrade. The IDS ability to measure ϵ r in-situ can potentially reduce maintenance, increase grid stability and improve safety.

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A new species of freshwater crab, Potamonautesisimangaliso sp. n., is described from the western shores of False Bay, Hluhluwe, within the iSimangaliso Wetland Park, South Africa.

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A new species of the cardinalfish genus Siphamia is described from specimens collected in the Province of West Papua, Indonesia, at depths of 50-72 m. Siphamia papuensis n. sp.

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This study used phylogenetic analyses of mitochondrial cytochrome b sequences to investigate genetic diversity within three broadly co-distributed freshwater fish genera (Galaxias, Pseudobarbus and Sandelia) to shed some light on the processes that promoted lineage diversification and shaped geographical distribution patterns. A total of 205 sequences of Galaxias, 177 sequences of Pseudobarbus and 98 sequences of Sandelia from 146 localities across nine river systems in the south-western Cape Floristic Region (South Africa) were used. The data were analysed using phylogenetic and haplotype network methods and divergence times for the clades retrieved were estimated using *BEAST.

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The cardinalfishes Archamia bilineata and A. pallida were originally described from a small number of specimens collected in the Gulf of Aqaba, Red Sea and Oman, respectively. Both species are re-described using specimens collected recently in Yemen and Kenya, including the first known adult of A.

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Novel microstructured PVA phantoms mimicking fibrous tissues have been developed using a simple freeze-casting process. Scanning electron micrographs reveal highly anisotropic microstructure with dimensions of the order of 5 to 100 microm. Characterization of an example phantom revealed acoustic properties consistent with those found in fibrous tissues.

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