OpenUCT :: Browsing by Subject "taxonomy"

Browsing by Subject "taxonomy"

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Belesica madiba and Cremastus tutui (Ichneumonidae: Cremastinae) two entomological gems from South Africa
(2014) Rousse, Pascal; van Noort, S
The Afrotropical cremastine fauna (Hymenoptera: Ichneumonidae) is characterized by the near absence of the genus Cremastus, with a single species reported from Madagascar. The fauna is also characterized by the presence of several endemic genera. Among the latter is the exceptional monotypic genus Belesica. We describe two new species from these extremely rare Afrotropical genera, namely Belesica madiba sp. nov. and Cremastus tutui sp. nov.. Both are only known from South Africa.
Open Access
Identity and distribution of southern African sciaenid fish species of the genus Umbrina
(2005) Hutchings, K; Griffiths, M H
Two Umbrina species, U. canariensis Valenciennes 1843 and U. robinsoni Gilchrist and Thompson 1908, are recognised from southern Africa. The latter species was hitherto believed to be a synonym of Umbrina ronchus Valenciennes 1843 (type locality Canary Islands). U. canariensis is distributed along the South Africa eastern seaboard from Cape Point to Sodwana Bay and U. robinsoni is known from False Bay to Madagascar and Oman. African Umbrina taxonomy has, however, been hindered by geographic samples that were either too few or consisted of specimens of disparate length; and as a result the identification and distribution of South African Umbrina species was confused. Morphological comparison of a large number of South African Umbrina with specimens from the type locality (Canary Islands) confirmed the identity of South African U. canariensis and allowed for an expanded description of the species. However, differences between specimens of U. ronchus and those of the second South African species (n = 251) led us to resurrect U. robinsoni (Gilchrist and Thompson 1908) as a valid name for this species. U. robinsoni differs from U. ronchus in having a smaller supraoccipital crest and thus a less steep pre-dorsal profile; a shallower preorbital bone (13–21% head length [HL] vs 21% HL); and a shorter nostril-orbit distance (2.4–6.9% HL vs 7.8–8.5% HL). Colour patterns also differ between the two species, with U. ronchus lacking the oblique, wavy, white stripes evident on the flanks of U. robinsoni. U. ronchus does not occur in South African waters, and is an eastern Atlantic species occurring from Gibraltar to Angola. Specimens from the east coast of Africa (Moçambique to Gulf of Oman) that were previously identified as U. ronchus are U. robinsoni. Differences between U. robinsoni and U. canariensis include: a lower modal number of soft dorsal fin rays, (22–27 vs 24–30); less deep body depth, (26–36% standard length [SL] vs 33–39% SL); shorter pectoral fin length (15–21% SL vs 20–25% SL); longer caudal peduncle length (26–34% SL vs 21–28% SL) and snout length (27–38% HL vs 23–32% HL); and smaller orbit diameter (14–33% HL vs 23–34% HL). Otoliths of U. robinsoni differ from those of U. canariensis in being smaller, less elongate, lacking a massive post-central umbo and having a post-dorsal spine remnant. The body colour and nature of the striping pattern on the flanks differs markedly between the species: in U. robinsoni the oblique stripes are thin, wavy, white lines; in U. canariensis the oblique stripes are thicker, nearly straight and brown; U. robinsoni also lacks the triangleshaped mark on the outer operculum and the dark pigmentation of the inner operculum that is found on U. canariensis. Spatial analysis of South African specimens collected with a variety of gear revealed U. robinsoni to be a shallow-water species found from the surf-zone to 40m, whereas U. canariensis occurs predominantly from 40 to 100m depth. Although both species occur throughout the South African eastern seaboard, U. canariensis is most common west of the Kei River, where the shelf is wider. Examination of three specimens of U. steindachneri Cadenat 1950 confirmed the presence of a fourth sub-Saharan Umbrina species that is limited to tropical West African waters from Senegal to Angola. U. steindachneri differs from the other African Umbrina in having a high number of soft dorsal rays (28–29), a greater 3rd dorsal spine length (25–27% SL) and a very pronounced and convoluted striping pattern on the flanks.
Open Access
Microbial solvent formation revisited by comparative genome analysis
(2017) DYrre, Peter
Abstract Background Microbial formation of acetone, isopropanol, and butanol is largely restricted to bacteria belonging to the genus Clostridium. This ability has been industrially exploited over the last 100 years. The solvents are important feedstocks for the chemical and biofuel industry. However, biological synthesis suffers from high substrate costs and competition from chemical synthesis supported by the low price of crude oil. To render the biotechnological production economically viable again, improvements in microbial and fermentation performance are necessary. However, no comprehensive comparisons of respective species and strains used and their specific abilities exist today. Results The genomes of a total 30 saccharolytic Clostridium strains, representative of the species Clostridium acetobutylicum, C. aurantibutyricum, C. beijerinckii, C. diolis, C. felsineum, C. pasteurianum, C. puniceum, C. roseum, C. saccharobutylicum, and C. saccharoperbutylacetonicum, have been determined; 10 of them completely, and compared to 14 published genomes of other solvent-forming clostridia. Two major groups could be differentiated and several misclassified species were detected. Conclusions Our findings represent a comprehensive study of phylogeny and taxonomy of clostridial solvent producers that highlights differences in energy conservation mechanisms and substrate utilization between strains, and allow for the first time a direct comparison of sequentially selected industrial strains at the genetic level. Detailed data mining is now possible, supporting the identification of new engineering targets for improved solvent production.
Open Access
Morphology, evolution and taxonomy of Wachendorfia (Haemodoraceae)
(1992) Helme, N E; Linder, H P
Wachendorfia Burm. is a small genus endemic to the Cape Floral Region. Pour species are recognised in this study. Two species were originally described by Burman in 1757 and these were followed by numerous other descriptions of what is essentially one very variable species (W. paniculaia Burm.). This variation is discussed and reasons are given as to why the recognition of formal infraspecific taxa is inappropriate. Formal taxonomic descriptions, distribution maps and a key to the species are provided. Rhizome morphology, leaf anatomy and pollen and seed coat structures were investigated and illustrations are provided. A cladogram was inferred and this is consistent with an ecological speciation model for the genus. The two species with the most restricted distribution (W. brachyandra W.F. Barker and W. pamfiora W.F. Barker) are considered to be the most recently evolved. Features of systematic and ecological interest (e.g. floral enantiomorphy) are discussed.
Open Access
New records and new species of Asclepiadaceae from Namibia
(1995) BRUYNS, P V
Eleven species of Asclepiadaceae not previously recorded from Namibia are discussed. Of these. Brachystelma codonanthum Bruyns. B. recurvatum Bruyns and Schizoglossum saccatum Bruyns are new species. The new combinations Brachystelma gymnopodum (Schltr.) Bruyns (for Ceropegia pygmaea Schinz) and B. schultzei (Schltr.) Bruyns [for Tenaris schultzei (Schltr.) E. Phillips] are proposed and the delimitation of Brachystelma R. Br. against Ceropegia L. and Tenaris E. Mey. is discussed. Notes are also included on little-known species, and the species of Gomphocarpus R. Br. in Namibia are enumerated.
Open Access
Psoralea margaretiflora (Psoraleeae, Fabaceae): A new species from the Sneeuberg Centre of Floristic Endemism, Eastern Cape, South Africa
(2011) Stirton, Charles; Clark, Vincent; Barker, Nigel; Muasya, Muthama
AbstractA new species of Psoralea is described. Psoralea margaretiflora C.H. Stirton & V.R. Clark is endemic to the Sneeuberg Centre of Floristic Endemism, Eastern Cape, South Africa. This resprouter is characterised by its small greenish-white flowers with a small trifid purple nectar patch and translucent veins; 5(–7)-pinnate leaflets; multi-branching erect short seasonal flowering shoots; and tall habit of many stiff bare stems with the seasonal shoots massed at the apex. It is most similar to Psoralea oligophylla Eckl. & Zeyh., a widespread species found in the Eastern Cape. The reseeder Psoralea oligophylla differs in its lax virgate spreading habit with numerous long glaucous seasonal shoots; single stem, 1(–3)- glaucous leaflets; more numerous white flowers; and standard petals with a purple ring surrounding a bright yellow nectar patch.
Open Access
Review of Afrotropical Figitinae (Figitidae, Cynipoidea, Hymenoptera) with the first records of Neralsia and Lonchidia for the region
(2014) Van Noort, Simon; Buffington, Matthew L; Forshage, Mattias
The cynipoid subfamily Figitinae is poorly represented in the Afrotropical region with two genera (Figites Latreille and Xyalophora Kieffer) and six species currently known. Here we record an additional two genera (Neralsia Cameron and Lonchidia Thomson) for the region and describe three new species: Neralsia haddocki sp. n.; Xyalophora tedjoansi sp. n.; Xyalophora tintini sp. n. Benoit’s species described in 1956 are synonymized under Figites aciculatus (Benoit, 1956): Figites effossus syn. n.; Figites favonius syn. n.; Figites furvus syn. n.; Figites fraudator syn. n. Identification keys to the figitine genera and species occurring in the Afrotropical region are provided. Online interactive Lucid Phoenix and Lucid matrix keys are available at: http://www.waspweb.org/Cynipoidea/Keys/index.htm
Open Access
Taxonomic studies in the Aizoaceae from South Africa: three new species and some new combinations
(2000) Klak, C
Two new species of Brownanthus, B glareicola Klak and B fratemus Klak and one new species of Scopelogena, S. bruynsii Klak are described. S. gracilis L.Bolus is reduced to synonymy under S. verruculata (L.) L Bolus. Three new combinations are made: Antimima excedens (L.Bolus) Klak. Erepsia dunensis (Sond.) Klak and Hammeria meleagris (L.Bolus) Klak and full synonomy is given Lampranthus maximilianii (Schltr. & A.Berger) L Bolus is transferred back to Braunsia maximilianii (Schltr. & A Berger) Schwantes and the identity of Ruschia polita L Bolus is discussed. The taxonomic position of Mesembryanthemum purpureostylum L.Bolus is clarified.
Open Access
Use and usefulness of measures of marine endemicity in South Africa
(2016) Griffiths, Charles L; Robinson, Tamara B
Abstract Numerous authors have cited numbers, or proportions, of endemic species within South(ern) African marine taxa, but comparisons between these statistics are confounded by differing definitions of regional boundaries and differences among data sets analysed. These have resulted in considerable variations in published endemicity data, even within the same taxonomic group. We tabulated and compared key endemicity statistics for regional marine taxa and explained biases in the data sets. The most comprehensive data sets available give overall marine endemicity within the national boundaries of South Africa as 28–33%, but estimates within individual taxa making up these totals vary enormously, from 0% (Aves, Mammalia) to over 90% (Polyplacophora). We also examined published data documenting localised endemicity patterns around the coastline. These consistently show the highest numbers of endemics occurring along the South Coast. There are logical biogeographical reasons to expect this trend, but endemicity rates are also inherently biased by distance from defined political boundaries and by differing sampling effort locally and in neighbouring countries. Range restriction is considered a better measure of conservation status than endemicity, although it is far less often used and yields very different patterns. Properly and consistently calculated measures of national endemicity do, however, retain significant conservation value, and the rates for South Africa marine biota are high relative to other regions globally, being exceeded only by New Zealand and Antarctica. It is important that when citing endemicity statistics, researchers and conservation managers understand the definitions used and the many constraints under which these measures are derived.
Open Access
Vegetative morphology and interfire survival strategies in the Cape Fynbos grasses
(1990) Linder, H P
It is shown that there is a wide range of structural variation in the habit of the Arundineae and Ehrharteae of the fynbos of the Cape Floristic Region (Cape Province, South Africa). Structural differences in the bases of the fynbos grasses have been classified into four groups: swollen, knotty tillering, weak and annual. Variation in the position of the innovation buds occurs with one group having basal perennating buds, implying that all the culm material is annual, while the second group has cauline innovation buds, leading to the development of a divaricate perennial herb. The recognition of caducous, mesic (orthophyllous) and sclerophyllous leaf blades is also possible, based on leaf morphology and anatomy. These variations in growth forms allow the classification of the Cape grasses into five guilds adapted for survival in the dense fynbos vegetation that develops between the well-spaced fires in these heathlands. The following guilds have been recognized: competition avoiders that grow on rock ledges and outcrops where competition from shrubby vegetation is reduced; reseeders, that survive the protracted interfire period as seed; geophytes, that survive this period as underground organs; coppicers, that survive as small plants; and competitors, that grow tall by means of cauline innovation buds, and so are able to compete with the shrubby heath vegetation.

Browsing by Subject "taxonomy"

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