Considering South Africa’s richness in aquatic species, very little knowledge exists regarding copepods that are symbiotic on hosts ranging from invertebrates to marine mammals. In order to have any indication of the existing biodiversity of this group of organisms in South African waters, a thorough investigation of all possible hosts needs to be conducted, which in turn will most likely increase the number of recorded symbiotic copepods considerably. The current descriptive study was done in an effort to contribute to a larger study of metazoan parasites of elasmobranch hosts along the KwaZulu-Natal coast of South Africa. A total of 40 (31 Mobula kuhlii; two Mobula eregoodootenkee and seven Manta alfredi) mobulids were examined for infection by symbiotic copepods at the KwaZulu-Natal Sharks Board (KZNSB). More than 90% of all examined hosts were infected with different types of symbiotic siphonostomatoids. Collected copepod specimens were fixed and preserved in 70% ethanol and studied with both the stereo- and light microscopes using the wooden slide technique. Some selected specimens were further studied using Scanning Electron Microscopy (SEM) to elaborate on ill-defined features. A total of 13 different species of the order Siphonostomatoida distributed over five families were identified. The five families include Eudactylinidae (Eudactylina oliveri, Eudactylina diabolophila and Nemesis sp.); Caligidae (Caligus crysophrysi, Pupulina sp. 1, Pupulina sp. 2; Pupulina sp. 3, Unidentified sp. 1, Unidentified sp. 2 and Unidentified sp. 3); Kroyeriidae (Kroeyerina mobulae); Dichelesthiidae (Anthosoma crassum) and Cecropidae (Entepherus laminipes). Two of the 13 species (E. laminipes and A. crassum) are monotypic and were therefore easily identified. Eudactylina oliveri exhibited a prevalence of 75% and 100%; mean intensity of 42 and 130 parasites per host and a mean abundance of 32 and 130 individuals per host while Pupulina sp. 1 exhibited a prevalence of 61.29% and 100%; mean intensity of 41 and 5 individuals per host and a mean abundance of 2 and 5 individuals per host on M. kuhlii and M. eregoodootenkee respectively. Component populations of E. oliveri and Pupulina sp. 1 exhibited an aggregated distribution pattern on their examined hosts. The phylogenetic relationship between nine caligid species (three known Pupulina species, three collected Pupulina species and three Unidentified sp. species as ingroup) with Caligus glandifer as out-group was determined and analysed using a morphological dataset (40 characters) from previous and current descriptions. The ii exhaustive search with PAUP* retained a single most parsimonious tree with a tree length (TL) = 85; consistency index (CI) = 0.7; retention index (RI) = 0.7; homoplasy index (HI) = 0.3 and a rescaled consistency index (RCI) = 0.5. Bootstrap support for the estimated clades was mostly low with values less than 95%. The phylogenetic hypothesis of the 10 caligid species presented in the current study was derived from the phylogenetic analysis of the information for adult females and is therefore not intended to be a definitive theory but should be treated as a testable hypothesis that can be further analysed using more data. The current study provides the first record of C. chrysophrysi, Pupulina sp. 1, Pupulina sp. 2, K. mobulae and E. laminipes on M. kuhlii; E. oliveri, Pupulina sp. 1, Pupulina sp. 2 and Pupulina sp. 3 on M. eregoodootenkee; and E. diabolophila, Nemesis sp., C. chrysophrysi, E laminipes, A. crassum and the three Unidentified species on M. alfredi frequenting the east coast of South Africa and thus contributes to the knowledge of our marine biodiversity. Mobulid hosts were not carefully studied for copepod infection previously and the copepods that were reported from the mobulids were probably found by chance. Therefore future investigation into the symbiotic siphonostomatoids of more mobulid hosts and other host species may result in more reports of symbiotic Copepoda from South African waters. / Thesis (MSc. (Zoology)) -- University of Limpopo, 2013

The genus Phytophthora includes many agriculturally and ecologically important plant pathogens. Characterization of new Phytophthora species is the first and a most critical step to understanding their biology, ecology and economic importance. Six novel Phytophthora species recovered from irrigation systems at ornamental plant nurseries in Mississippi and Virginia were described based on morphological, physiological and molecular characters: 1. Phytophthora mississippiae sp. nov. produces a mix of non-papillate and semi-papillate sporangia, and catenulate hyphal swellings. It is a heterothallic species. All examined isolates of P. mississippiae are A1. When paired with A2 mating type testers, P. mississippiae produces ornamented oogonia and amphigynous antheridia. It is phylogenetically grouped in Phytophthora subclade 6b based on sequences of the rRNA internal transcribed spacer (ITS) region and the mitochondrially encoded cytochrome c oxidase 1 (cox 1) gene. 2. Phytophthora hydrogena sp. nov. is heterothallic. It produces non-caducous and non-papillate sporangia. It is characterized by frequently producing widening at the pedicel tip of sporangiophores or tapered sporangial based toward the point of attachment. This species is phylogenetically placed in a high-temperature tolerant cluster in Phytophthora clade 9. All members in this cluster grow well at 35 C. 3. Phytophthora virginiana sp. nov. is a self-sterile species. All examined isolates are silent A1. It produces non-caducous and non-papillate sporangia and is also placed in the high-temperature tolerant cluster in clade 9. Morphologically, it is characterized by producing abundant thin-walled, lateral chlamydospores in carrot agar and clarified V8 juice agar. 4. Phytophthora macilentosa sp. nov. is a heterothallic species. Only A1 isolates have been found. It produces characteristic elongated, non-papillate sporangia. It is also a member of the high-temperature cluster in clade 9. 5. Phytophthora stricta sp. nov. is a heterothallic species. It produces unique non-papillate and slightly caducous sporangia with one to three constrictions on its sporangiophore. Phylogenetically, P. stricta represents a new ITS clade within the genus. 6. Phytophthora Xstagnum nothosp. nov. is a novel hybrid species with P. taxon PgChlamydo as its paternal parent and a P. mississippiae-like species as its maternal parent. This new hybrid produces intercalary chlamydospores and catenulate hyphal swellings, which are morphological characters of P. taxon. PgChlamydo and P. mississippiae, respectively. It also produces both smooth-walled and ornamented oogonia, which may be indicative of oogonial characters of its paternal and maternal parents, respectively. By incorporating new Phytophthora species, clusters and clades, phylogenies including approximately 128 Phytophthora taxa were constructed based on sequences of five genetic markers. Among the selected genetic markers, the beta-tubulin (B-tub) gene provided the highest phylogenetic resolution. General phylogenetic structure of the B-tub phylogeny was similar to that in previous multi-locus phylogenies, except that P. cinnamomi, P. parvispora, P. quercina, P. stricta, and a provisional species, P. sp. e1, were not clustered in any of the 10 known Phytophthora clades and represented new clades. The B-tub phylogeny was also used to study the correlations between phylogeny and morphological characteristics including sporangial papillation, caducity, homothallism, and antheridial configuration, as well as maximum growth temperature. The results indicated that the character of sporangial papillation was mostly consistent among species within individual subclades. Maximum growth temperature was also generally correlated with phylogenetic positions. Consistency in caducity, homothallism or antheridial configuration was not found. A new multi-locus phylogeny based on sequences of 11 genetic markers of more than 146 Phytophthora species was proposed to validate new clades and clusters, as well as investigate detailed phylogenetic relations among species in this quickly expanding, taxonomically complex group of plant pathogens. / Ph. D.

No description available.

<p dir="ltr">In a rapidly changing world, human actions and natural events are reshaping ecosystems and presenting new challenges for conservation efforts. Within this context, unraveling the recent ecosystem transformations and their implications on a fine scale is required. The impacts of such changes are not always sudden but often gradual and sometimes as a result of historical events. With the recent advancement in technologies, the resolution of information by genome sequences spans from millions of years ago (hindcasting) to future generations (forecasting). Aquatic ecosystems pose their own challenges when it comes to ecosystem changes and the types of data required to assess impact and help inform conservation efforts. My dissertation comprises three chapters focused on using genomic techniques to generate data valuable for the conservation and management of aquatic ecosystems. Each of the three chapters is a distinct manuscript in terms of scientific publications, where Chapter 1 has already been published, Chapter 2 has been submitted to a journal, revised, and is now awaiting publication, and Chapter 3 is in preparation for submission to a peer-reviewed journal. In Chapter 1, dietary DNA from harvested North American river otter (<i>Lontra canadensis</i>)<i> </i>was used to determine whether metabarcoding of stomach content could be used to identify fish prey species consumed. In Chapter 2, DNA sequencing of endangered pupfish species in the Tularosa Basin of New Mexico was studied; before my work, it was nominally comprised of a single species, the White Sands pupfish (<i>Cyprinodon tularosa</i>). The results indicate a rapid speciation event occurred within about the last ~5000 years, driven primarily by genetic drift. Chapter 3 extends Chapter 2 by assessing the dynamics of genomic diversity over space and time while evaluating the short-term evolutionary dynamics (~18 generations) of the two native pupfish populations. This temporal study aimed to determine if the extraordinarily rapid evolution over the last ~5000 years (observed in Chapter 2) could be detected over timescales more relevant to conservation and management efforts. Overall, this dissertation used genomic sequence data from metabarcoding of the COI gene region in the otter stomach content as well as pool sequencing and whole genome resequencing of pupfish to provide key biological insights into the conservation of these aquatic species. This dissertation also provides insights into avenues for further study and highlights the significant role that conservation genomics can play in the future. The findings presented in the three chapters are discussed within the context of species’ conservation and management.</p>

The aim of this literature study was to investigate the effects of biofouling in the Baltic Sea. This was done to increase environmental awareness and understanding of the importance of a sustainable marine environment. A systematic search in selected databases resulted in the study being based on tio research articles. The overall results of the study show that biofouling demonstrate negative effects, but the effects are not fully understood to date and the focus is still on economic aspects. Furthermore, it was observed that the studied organizations are currently focused on greenhouse gas issues, but they have also been paying attention to biofouling problems in recent time. The literature study provides important insights into the effects of biofouling.

Les espèces exotiques envahissantes sont un sujet de préoccupation grandissant, mais sont-elles,pour le droit international, un objet comme un autre ? Une espèce exotique envahissante a comme particularité d’être une espèce vivante qui, par sa seule présence dans un écosystème qui lui est étranger, va engendrer des effets délétères alors qu’elle n’en aurait causé aucun dans son écosystème d’origine. Le droit de la mer est-il armé pour répondre à cette menace ? La question de la qualification de leur atteinte en droit international et plus précisément en droit de la mer est autant novatrice que capitale. Le traitement juridique des espèces exotiques envahissantes a consisté, jusqu’à maintenant, à les rattacher de facto à la lutte pour la conservation de la diversité biologique sans même que soit posée la question, en amont, de leur qualification. Et si les espèces exotiques envahissantes étaient considérées comme une pollution ? Envisager cette hypothèse implique de procéder à une étude de fond tant des instruments de droit international, et de droit de la mer en particulier, que de la pollution marine. S’il est permis de reconnaître les espèces exotiques envahissantes comme étant une source de pollution, elle n’en reste pas moins une nouvelle forme de pollution encore jamais reconnue par les instruments de droit international : une pollution biologique. Cette pollution, autonome de celles déjà existant en droit international,impliquant la nécessité de repenser la définition de la pollution marine. / Alien invasive species are a growing concern, but are they an object as any other in international law ? An invasive alien species is a living species which, by its mere presence in an ecosystem outside its natural range, causes deleterious effects which is not the case in its native ecosystem. Is the law of the sea equipped to meet this new threat ? The classification of its effects in international law, and more specifically the law of the sea, is as innovative as capital. The legal treatment of invasive alien species so far has been tied to the struggle for the conservation of biological diversity without wondering, in advance, what its classification is. What if alien invasive species are considered pollution ? Considering this hypothesis means studying instruments of international law, and more precisely those of the law of the sea, as well as marine pollution. If one can allow to identify invasive alien species as a source of pollution, it remains a new form of pollution that has never been recognized before by the instruments of international law : a biological pollution. This pollution, independent of those already existing in international law, implies the need to rethink the definition of marine pollution.

Le concept de développement durable fut promu à la Conférence de Rio de 1992avec l’adoption d’un certain nombre d’instruments juridiques. Le droit africain s’estprobablement adapté aux règles et aux principes inhérents au concept avec, commeconséquence, la refonte ou la révision des codes ou lois de protection del’environnement. Face aux problèmes environnementaux récurrents, à la difficilegestion intégrée des ressources en eau, à l’opérationnalisation critique de la solidaritéà l’eau potable pour tous, à la gouvernance environnementale défaillante, la questionde l’évolution efficiente du droit de l’environnement africain au regard du conceptde développement durable se pose. Il se révèle un insuccès de la saisie du conceptpar le droit africain. Au final, un nouveau modèle de droit de l’environnement, auprofit des pays de l’Afrique de l’Ouest, s’avère nécessaire. / The concept of sustainable development was promoted in the Rio Conference in1992 with the adoption of a number of legal instruments. African law has probablyadapted to the rules and principles inherent to the concept with, as a consequence,consolidation or revision of codes and laws to protect the environment. Facingrecurrent environmental problems, the difficult Integrated water resources, criticaloperationalization of solidarity drinking water for all, the failed environmentalgovernance, the question of the efficient development of the law of the Africanenvironment in relation to the concept of sustainable development arises. It proves afailure in the seizure of the concept by the African law. Finally, a new model ofenvironmental law in favor of the countries of West Africa is necessary.