Description of Caprionchulus diversipapillatus n.gen., n.sp. from Caprivi, Namibia (Nematoda: Onchulinae)

Caprionchulus diversipapillatus n.gen, n.sp. was found in a small fresh-water pond in eastern Caprivi. The new genus differs from all other genera within the subfamily Onchulinae Andrássy, 1963 in the almost barrel- shaped stoma containing a single dorsal tooth, an elongated cardia comprising three vertical rows of four cells each and peculiar supplements consisting of two conspicuous adanal setae and a row of six to eight papilloid supplements, the last four of which are in pairs. The spicule shape is also different from other members of the Onchulinae

Description of Aetholaimus trochus n.sp. and the male of Ironus ignavus Bastian, 1865 (Nematoda) from Caprivi, Namibia

Two species of the genera Aetholaimus Williams, 1962 and Ironus Bastian, 1865 from the remote eastern Caprivi, show some remarkable morphological features, which are presenled here In photomicrographs, Aetholaimus trochus n.sp. can be distinguished from all other species within the genus by its long body, long prerectum, long mural tooth, short odontophore and presence of males. Males of Ironus ignavus Bastian, 1865 are reported and described for the first time

Studies on Haliplectus Cobb, 1913. A diagnostic species compendium of the genus Haliplectus and notes on intraspecific variation in H. bickneri Chitwood, 1956

This last part of a series on Haliplectus Cobb, 1913 includes a species compendium of the genus and a brief comparative study of different populations of H. bickneri Chitwood, 1956

Description of Tobriloides loofi n. sp. from natal, South Africa (Nematoda: Onchulidae)

Tobriloides loofi n. sp. has a huge cardia, three whorls of cephalic setae and an onchulid structure of the posterior oesophagus, which place it in the rare genus Tobriloides Loof, 1973. It differs mainly from the only other species in this genus, Tobriloides choii Loof, 1973, in its large size, the presence of males in T. loofi and the position of the vulva (midbody in T. loofi and more posterior in T. choii). This is the first description of a member of the genus Tobriloides from South Africa, as well as the first record of a new species within this genus in 16 years. Line drawings, light- and scanning electron micrographs are included in the text, as well as a short discussion of intergenus relationships of Tobriloides

Studies on Haliplectus Cobb, 1913. Description of Haliplectus algoensis n. sp. (Nematoda: Haliplectidae, Suborder Leptolaimina)

Specimens of the genus Haliplectus Cobb, 1913 which exhibited remarkable morphological detail were collected from coastal dune slacks in the Alexandria dune field east of the Sundays River, near Port Elizabeth, on the shore of Algoa Bay. These specimens differ from closely related species mainly in greater body length, equatorial position of the vulva and the number of supplementary organs in the male (n = 3). They are described herein as belonging to a new species, H. algoensis n.sp

Namaquanema hanki n. gen., n. sp. from South Africa (Nematoda : Dorylaimoidea)

Summary -Namaquanema hanki n. gen., n. sp. is described from South Africa. The new genus, which is placed in the Dorylaimidae, is distinguished by an amalgamated Iip region; a stylet without sclerotized odontophore but with short hooked processes at the base of the odontostyle; guiding ring double; ta il short in both sexes, dimorphic in type species; female didelphic, with longirudinal vulva sunken deep below body surface; male with numerous contiguous ventromedian supplements and long prerecrum. Résumé -Namaquanema hanki n. gen., n. sp. provenant d'Afrique du Sud (Nematoda : Dorylaimoidea) -Description est donnée de Namaquanema hanki n. gen., n. sp. provenant d'Afrique du Sud. Ce nouveau genre, placé dans les Dorylaimidae, se caractérise par une région labiale compacte, un stylet sans odontophore maIs pourvu de procès en fonne de crochet à la base de l'odontostyle, un guide du stylet à double anneau, une queue courte chez les deux sexes, et dimorphique chez l'espéce type, une femelle didelphique présentant une vulve en fente longirudinale profondément enfoncée en-dessous de la surface du corps, un mâle pourvu de nombreux suppléments ventro-médians contigus et un long prérecrum

Nematodes down under: State of knowledge and future trends

Nematodes inhabit most environments that address their need of water, carbon, and energy. They also play an important role in epigean food webs by occupying different trophic levels, while providing essential ecosystem services such as regulating decomposition and nutrient mineralization. Conversely, little is known about the role that nematodes play in subterranean ecosystems. For this reason, an in-depth review was undertaken in order to concatenate data from existing literature and provide a baseline for future studies. A total of 41 surveyed scientific works, published over a time period of 138 years, reported 295 unique taxa from 78 different cave systems. Although an increase in scientific outputs was recorded from the late 1990s, there is a considerable lack of information on cave-dwelling nematodes from Asia, South America, and North America. Also, only seven true cave-dwelling (troglobitic) species have been discovered, which may indicate a lack of comprehensive taxonomic efforts. From an ecological perspective, very few works have reported on the importance of nematode assemblages associated with cave ecosystems. This has resulted in the causal factors leading to population resilience processes, as well as trophic interactions, remaining mostly speculative. Nonetheless, the isolated cave-dwelling nematode assemblage associated with Movile Cave, including the true cave-dwelling species Chronogaster troglodytes, fulfills an important role by feeding on microbial mats and in turn serving as a food source for predators. This example of a cave nematode assemblage providing ecosystem services has inspired the undertaking of the Gcwihaba Caves Research Project, which aims at studying artificially opened caves in Ngamiland, Botswana. Compared to other caves in the area with natural openings, the artificially opened systems present different food source pathways, atmospheric conditions, and community assemblage structures. This provides a unique opportunity to study isolated cave communities, including nematode assemblages, as well as their ecological importance

Morphology and taxonomy of some nematodes of the orders Teratocephalida, Enoplida, Dorylaimida, Chromadorida and Isolaimida

D.Phil. (Nematology)The science of taxonomy or the organisation and labelling of organisms may strike many as dull and stuffy but everyone working in this fascinating field finds that it leads to some of the most searching and interesting questions. Taxonomists are confronted by a well organised world of nature, exactly that what prompted the great taxonomist Linnaeus to develop his clear, hierarchical method of classification. But at the same time they are faced with a bewildering diversity and variation within this organised whole. Seeking to order the stable units in the midst of this diversity is the descriptive task of taxonomy. But many taxonomists go further than that, they seek a theory and ask: what causes life to be ordered? Here they land in the middle of philosophical debate and controversy. The field of taxonomy has, unfortunately, been divided by arguments about what a species is, how to demarcate a species, and even whether they are real or not. Today this "species question" is phrased in broader terms. The real question is not whether species are fixed but whether there is any stable, objective unit in nature. What do the patterns of similarity and difference mean - creation according to a common plan with the potential of variation, or descent from a common ancestor with modifications? Charles Darwin believed that change is unlimited, that species are infinitely variable. He thought that species could vary indefinitely and in any direction. Creationists on the other hand, believe that change is limited by a basic organic "unit", the "created kind" and within the boundary of that fundamental unit, variation can be profuse, but it can never lead to the creation of a new basic type. This is near the essentialism as taught by Aristotle nearly 2000 years ago. Aristotle thought that each species embodies an eternal, unchanging ideal or archetype. The problem with this view is that it assumed a single form or pattern. Most biologists until the time of Darwin held to the typological view, a view considered by many scientists today as very plausible. This theory holds that the organic world is discontinuous, that all major groups of organisms are separate and breed true to type. A species is also defined by a cluster of characteristics - each member of the species may have some but not all of the diagnostic features. Another view is cladism, founded by the entomologist, Willy Hennig. It is concerned with the patterns found in nature and involves the finding of the positive and verifiable characters of the various species and determining how all species fit into the animal kingdom

The Apadana reliefs at Persepolis: An iconographic analysis with special emphasis on the identification and function of the gift-bearing delegations

Thesis (DPhil)--Stellenbosch University, 2021.ENGLISH ABSTRACT: For many years, specific delegations on the façades of the Apadana at Persepolis posed an ongoing identification problem among scholars. Incongruities occurred in the identification of some of the groups – labelled Problem Groups in the current study. An attempt was made to try and solve the identification problem of specific delegations. It was necessary to look at the context in which these groups occurred, e.g., their physical world as well as their natural environment. The reliefs on the eastern façade of the Apadana was used in this study because they are still in a reasonably acceptable state. The combined iconographic analysis method (Panofsky/ Keel), as well as comparisons, were used to try and find a solution for the identification problem in the Problem Groups. After a detailed analysis and comparative research, the identification problem of the Problem Groups still evades answers except for one group. A totally different approach to the solving of the identification problem was suggested, and this deserves some attention from future scholars.AFRIKAANSE OPSOMMING: Geen Afrikaanse opsomming beskikbaar nie.Doctora