No description available.

The diversity, classification and historical biogeography of the mayfly family Prosopistomatidae are explored. First, the higher classification of the Ephemeroptera is reviewed, focussing on the phylogenetic placement of the Prosopistomatidae relative to other mayfly families. All relevant literature from 1762 to 2010 is synthesized. Baetiscidae are established as the probable sister lineage of Prosopistomatidae, the two constituting the superfamily Baetiscoidea. Next, qualitative morphological variation within the Prosopistomatidae is reviewed and revised, emphasizing nymphs because imaginal specimens are few. The labium and associated structures and the hypopharynx of nymphs, and the highly-derived wing venation of the imaginal stages, are re-interpreted. The structure of the male tarsal claws changes considerably between subimago and imago, which, together with deeply scalloped ridges on male imaginal forelegs and unusual pits on the female thorax, are interpreted as providing an unusual mating mechanism. These structures provide morphological characters for species definition and phylogenetic analyses. Two approaches to species delimitation are explored. First, morphometric variation is analysed using Principal Component Analysis, revealing groupings that can be interpreted as species, although there is some overlap between them. Discriminant Function Analysis shows that head width and carapace shape have the most value in identifying nymphs of different species. The carapace of Prosopistoma nymphs is shown to grow allometrically and gradually, in contrast with that of Baetisca, indicating a difference in early ontogeny. Second, an Artificial Neural Network algorithm applied to nymphal morphological characters accurately identified species. This computer-driven artificial intelligence method has power to provide future easy-to-use electronic identification aids. Phylogenetic analysis of nymphal morphology using the parsimony method shows two clades of Prosopistomatidae, one sharing characters with the type species, Prosopistoma variegatum and the other predominating in Africa, although also occurring in Asia; these clades are named the “P. variegatum” and “African” clades, respectively. Parsimony analysis of adult morphology supports these two clades, but supertree analysis obscures the relationships, nesting the “P. variegatum” lineage within the other clade. Preliminary molecular phylogenetic analysis of the 16S rRNA, (mitochondrial) 18S rRNA and Histone-3 genes using Bayesian Inference methods does not support the two clades shown by morphology. Instead, there is a strong relationship between the European species and one African species, with the single Asian representative being most distantly related. These results are limited by lack of fresh material, patchy taxon sampling, and problems with finding suitable primers. A molecular clock program, BEAST, calibrated using fossils, suggests divergence times for the oldest crown-group Prosopistoma clade, represented by the Asian P. wouterae, of about 131 Ma, with the youngest species, the African P. crassi, of 1.21 Ma. Stem-group relationships are analysed using parsimony analysis, focussing on wing characters of the Baetiscoidea, other extant mayfly lineages, and extinct stem-group lineages. This suggests that the Baetiscoidea diverged from main-line Ephemeroptera earlier than any other extant mayfly lineage. This approach expands upon ideas hinted at by earlier scientists. Finally, historical biogeographical analysis of the distribution of known Baetiscoidea s.s. stem-group fossils implies a once Pangean distribution of the lineage. Changing palaeo-climate, catastrophic extinction events and plate tectonic movements in relation to the distribution of crown-group species are reviewed. Other approaches to historical biogeography that build on both morphological and molecular phylogenies are used to interpret disperalist and vacarianist arguments. Distribution patterns of eight unrelated freshwater organisms which share a similar distribution pattern are compared, assuming that shared patterns indicate similar historic biogeographic processes. The distribution of recent Prosopistoma species is seen to be the product of evolution resulting from both vicariance and dispersal. In conclusion, this thesis encompasses a variety of disciplines. It successfully recognises new characters and distinguishes previously unknown species. It uses new approaches to delimiting species and known methods to determine phylogeny from several angles. The analysis of stem-group relationships offers an insight into possible early lineage splitting within Ephemeroptera. Interpretation of historical biogeography allows for both a Gondwanan origin of Prosopistomatidae, with rafting of species on the Deccan plate to Asia, and for subsequent dispersal from Asia down to Australia and across to Europe, and possibly back to Africa.

Thesis (Ph. D.)--Brigham Young University. Dept. of Integrative Biology, 2004. / Includes bibliographical references.

Thesis (M.S.)--University of Toledo, 2006. / Typescript. "Submitted as partial fulfillment of the requirements for The Master of Science Degree in Biology (Ecology-track)." Bibliography: leaves 26-34.

Thesis (M.S.)--Tennessee Technological University, 2009. / Title from title page screen (viewed on June 29, 2010). Bibliography: leaves 20-24.

Thesis (M.S.) University of Missouri-Columbia, 2005. / The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (July 10, 2006) Includes bibliographical references.

This thesis is an amalgamation of and a contribution to the knowledge of the Ephemeroptera of British Columbia, an order which has been largely neglected in Canada, and particularly in this province. The three families Heptageniidae, Ephemeridae, and Baetidae are replaced by the five superfamilies Heptagenioidea, Leptophlebioidea, Caenoidea, Ephemeroidea, and Prosopistomatoidea proposed by Edmunds and Traver (1954). 146 species in 23 genera have been recorded in British Columbia. Of these, 62 as yet unidentified species are designated by number. A checklist of all recorded species, and keys and descriptions of taxonomically important criteria of the species and higher ranks are included herein. A preliminary investigation of the ecology of the nymphs collected by the author in the Alouette River and by Dr. G.G.E. Scudder in the lakes of the Chilcotin, Cariboo, and Nicola Valley regions revealed no "preference" of the nymphs for the middle or edges of the river or for particle size of the substrate. An accurate determination of the latter, however, is not obtainable with the type of collecting equipment employed during this study. Some "preference" was shown by a number of species for specific rates of current flow. No correlation between the species of nymphs and the pH or the salinity of the environment was determined. Suggestions are put forward for the extension of our knowledge of the taxonomy, ecology, and biology of the Ephemeroptera. / Science, Faculty of / Zoology, Department of / Graduate

published_or_final_version / Ecology and Biodiversity / Doctoral / Doctor of Philosophy

No description available.

The Ephemeroidea or burrowing mayflies are a superfamily of the Ephemeroptera (mayflies) with a worldwide distribution. Recent decades have seen a sharp decline in their abundance globally. Literature reviews of the past 20 years have shown this superfamily to be well represented on the Mooi River, KwaZulu-Natal- five species (Eatonica schoutedeni, Ephemera mooiana, Afromera natalensis, Afroplocia sampsoni and Ephoron savignyi) were recorded during the 20th century. However recent fieldwork failed to confirm this professed diversity, recording only two species (Afromera natalensis and Ephoron savignyi). This work critically re-examined all of the literature relating to the Ephemeroidea of Africa (in the context of the five species recorded from KwaZuluNatal) published in Africa and Europe (as well as many publications from the rest of the world) during the 19th and 20th century. It was found that a number of oversights were made in much of this literature that have become assimilated into the understanding of the taxonomy and ecology of this group. Amongst these, it was found that the synonymisation of three species of Ephoron ( = Polymitarcys-Polymitarcys savignyi, P. capensis and P. temerata) in the 1920s was weakly justified. To clarify problems in the published record relating to the five species recorded from KwaZulu-Natal, some of the most important museum holdings in Europe and South Africa were re-examined. Two previously unknown collections of Ephemera sp. were found in European museums. One of these collections was made in West Africa, undermining theories that Ephemera sp. are only found in cold waters. This research confirmed that the records for Eatonica schoutedeni in KwaZulu-Natal are probably spurious, the result of misidentification. This work presents a review of the publications relating to each of the species of the Ephemeroidea recorded from KwaZulu-Natal. Lists of synonyms are provided. Descriptions from literature and museum specimens are given. The known distribution and biology of each is presented. The current status of the Ephemeroidea of KwaZulu-Natal are discussed and a new key to the species of Kwazulu-Natal is presented. In order to assess the purported diversity of Ephemeroidea in the rivers of the KwaZulu-Natal midlands, extensive fieldwork was carried out the Mooi River and on other tributaries of the Tugela and Mgeni rivers from 1998 to 2000. This investigation failed to reveal four of the five species indicated in the literature. The sole species that was found, Ephoron savignyi was abundant in some areas of the Mooi and Karkloof Rivers. This apparent drop in diversity may be because the sampling effort carried out from 1998 to 2000 was too limited in time and space to gather specimens of all the species resident in the river, or because environmental changes in the region in the last 50 years have resulted in the extirpation of any or all of the remaining four species. It is concluded that the records of Eatonica schoutedeni from KwaZulu-Natal are spurious; Ephemera mooiana is either not the only species in the genus Ephemera on the continent of Africa, or has a substantially wider distribution than previously thought; Afromera natalensis and Afroplocia sampsoni may be present on the rivers of KwaZulu-Natal but have not been found during this research; Ephoron spp. are abundant in KwaZulu-Natal, but further research is required to confirm that the species in South Africa are the same as those originally recorded from the type locality, Egypt. / Thesis (M.Sc.)-University of KwaZulu- Natal, Pietermaritzburg, 2004.