Made available in DSpace on 2015-10-06T13:03:22Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-06-08. Added 1 bitstream(s) on 2015-10-06T13:18:35Z : No. of bitstreams: 1 000849888.pdf: 959403 bytes, checksum: e9f8b03a191fa7e4bdb809755968d258 (MD5) / Organização dos Estados Americanos (OEA) / O mexilhão-dourado (Limnoperna fortunei) é um bivalve de água doce pertencente à família Mytilidae. Originário de rios e arroios da China e do sudeste asiático, a espécie foi introduzida acidentalmente na América do Sul em 1991, no estuário do rio da Prata, provavelmente através de água de lastro. A partir disso, dispersou-se para os rios Paraguai, Uruguai e Paraná, principais canais de drenagem da bacia do Prata. Devido ao seu grande potencial reprodutivo, crescimento rápido e capacidade de formar aglomerados populacionais em curto espaço de tempo, L. fortunei causa grandes alterações ecológicas e econômicas, como a obstrução nas canalizações e entradas de água de usinas hidrelétricas e redes de tratamento de água. O presente estudo teve como objetivo avaliar a distribuição de L. fortunei nos principais corpos d'água formadores da Bacia do rio da Prata, bem como a possível influência das condições ambientais sobre as densidades populacionais. Os dados foram obtidos a partir de amostragens realizadas em janeiro/fevereiro e junho/julho de 2010, com coletas complementares em junho de 2013 e fevereiro de 2014. Foram empregados arrastos verticais com rede cônica de 68 μm de abertura de malha para coleta das larvas e simultaneamente determinadas as variáveis limnológicas (temperatura, transparência, turbidez, pH, condutividade e oxigênio dissolvido). Conclui-se que o processo de dispersão da espécie se deu de uma forma muita rápida, uma vez que a sua chegada ao continente ocorreu há apenas duas décadas e atualmente encontra-se amplamente distribuída por toda a bacia (aproximadamente 15 graus de latitude e extensão linear de 1700 km). Isto se explica devido a elevada capacidade de dispersão intrínseca da espécie (larvas planctônicas livre-natantes), incrustação em embarcações e ampla tolerância aos fatores ambientais. Picos máximos de densidade, cerca de 60.000 ind.m-3, foram encontrados nos... / The golden mussel (Limnoperna fortunei) is a freshwater bivalve belonging to Mytilidae family. Originally from rivers and streams of China and Southeast Asia, the species was accidentally introduced in South America in 1991, in the River the la Plata estuary, probably through ballast water. From there, it dispersed to the rivers Paraguay, Uruguay and Paraná, major drainage channels of the basin. Due to its great reproductive potential, rapid growth and ability to form settlements in short time, L. fortunei cause major ecological and economic changes, such as blockage of the drainage system and water intakes of power plants and water treatment networks. This study aimed to evaluate the distribution of L. fortunei in the main water bodies of the River de la Plata Basin, as well as the possible influence of environmental conditions on the population densities. Data were obtained from samples taken in January/February and June/July 2010, with additional sampling in June 2013 and February 2014. Vertical hauls were employed with conical network of 68 μm mesh size to collect the larvae and the limnological variables (temperature, transparency, turbidity, pH, conductivity and dissolved oxygen) were simultaneously determined. It is concluded that the species dispersion process was very fast, since their arrival in the continent occurred just two decades ago and presently it is widely distributed throughout the basin (approximately 15 degrees latitude and a linear extension of 1700 km). This is explained by the high intrinsic dispersal ability of the species (free planktonic larvae), boat incrustation and broad tolerance to environmental factors. Maximum density peaks, about 60,000 ind. m-3, were found in the lower reaches of the basin, the River de la Plata ((URU/ARG), where the species was introduced. However, we refutes the hypothesis that there is a decreasing gradient of abundance in the south-north direction. Correlation analyzes indicate ...

Made available in DSpace on 2014-12-17T15:34:47Z (GMT). No. of bitstreams: 1 JulianaJA_DISSERT.pdf: 2116213 bytes, checksum: fc751829efa3c492850a246e32488677 (MD5) Previous issue date: 2013-02-19 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The objectives of this study were to characterize the goat production systems and to identify the factors limiting the production chain and develop solutions to improve the goat industry in the Rio Grande do Norte State, Brazil. One hundred and sixty two questionnaires were applied to goat farmers looking for productive, economic and social information about the utilized systems in the micro regions of Chapada do Apodi and Angicos. The majority producers interviewed were male, aging from 31 to 50 years old, attended elementary school, associated to farm organizations and living with his family on farm. Their main concerns are feeding the heard and animal theft. Their average farmlands areas range from 11 to 50 hectares. Goat meat is the main production in Chapada do Apodi whereas milk is produced by farmers in Angicos micro region. The majority of goat production works with an extensive system, with low technological inputs. It was detected that the meat and milk production as the marketing of goat products is not well conducted. Other point to be improved is to increase the meat and dairy goat products to be available for consumers. Goat systems for meat and milk production has great to potential for this micro regions, although public policies for an organized supply chain is needed / Os objetivos desta pesquisa foram caracterizar os sistemas de produ??o de caprinos, identificar os fatores limitantes e formular solu??es que promovam a melhoria da caprinocultura no Estado do Rio Grande do Norte. Para isso, foram aplicados 162 question?rios contendo par?metros produtivos, econ?micos e sociais. O levantamento foi realizado nas microrregi?es de Chapada do Apodi e Angicos, essas foram escolhidas, por deterem o maior efetivo e maior densidade de caprino. Identificou-se que a maioria dos produtores entrevistados ? do sexo masculino, est? na faixa et?ria de 31 a 50 anos, cursou apenas o ensino fundamental incompleto, participa de afilia??es e reside com sua fam?lia na propriedade. Suas principais preocupa??es s?o com a alimenta??o do rebanho e o roubo de animais. Sua propriedade tem em torno de 11 a 50 hectares. A caprinocultura de corte ? mais praticada na Chapada do Apodi e a de leite na microrregi?o de Angicos. O sistema de produ??o mais utilizado ? o extensivo. Quanto ? produ??o e comercializa??o dos produtos, nota-se que existe uma defici?ncia na diversidade de produtos e uma necessidade de ampliar o mercado consumidor, assim percebe-se que a caprinocultura apresenta grande potencial para tornar-se um setor lucrativo da regi?o, por?m necessita de pol?ticas que incentivem os produtores na ado??o de medidas para organizar a cadeia produtiva

Morphological-taxonomical study of gryporhynchid cestodes from Africa is presented. New material from Kenya, Senegal and Sudan was studied and we belong to 17 species in 8 orders - Amirthalingamia macracantha (Joyeux et Baer, 1935) Bray, 1974; Anomotaenia riccii (Fuhrmann et Baer, 1943) Baer et Bona, 1960; Cyclustera magna (Baer, 1959) Bona, 1975; Cyclustera sp.; Dendrouterina macrosphincter (Fuhrmann, 1909) Baer et Bona, 1960; Neogryporhynchus sp.; Paradilepis lloydi (Southwell, 1926) Spasski, 1954; Paradilepis maleki (Khalil, 1961); Paradilepis urceina Bona, 1975; Paradilepis urceus (Wedl, 1855) Joyeux et Baer, 1950; Parvitaenia macrocoleo Bona, 1975; Parvitaenia macropeos (Wedl, 1855) Baer et Bona, 1960; Parvitaenia megascolecina Bona, 1975; Parvitaenia purpurea Johri, 1959; Parvitaenia samfyia Mettrick, 1967; Valipora ardeolae (Singh, 1952) Baer et Bona, 1960 and Valipora mutabilis (Linton, 1927). Known larval stages and adults from Africa are presented in review of species.

A ocorrência do ácaro vermelho das palmeiras (AVP), Raoiella indica Hirst (Acari: Tenuipalpidae), foi relatada no Novo Mundo em 2004 e desde então este ácaro tem colonizado várias espécies de aceráceas e musáceas, assim como plantas ornamentais de outras famílias nas ilhas do Caribe, Florida (USA), Venezuela, Brasil e Colômbia. Desde aquele primeiro relato, essa espécie tem produzido consideráveis perdas econômicas em coqueiro nos países onde foi encontrada, o que tem conduzido a um interesse cada vez maior em se conhecer o impacto da praga às plantas em que este ácaro tem sido encontrado. Com o objetivo de conhecer aspectos bioecológicos do AVP na Venezuela foram feitas amostragens para determinar a distribuição geográfica nesse país assim como as plantas hospedeiras e inimigos naturais com os quais a praga tem sido encontrada. A biologia da praga foi estudada em plantas ornamentais e em espécies de palmeiras nativas do Neotrópico, para avaliar o seu potencial em causar dano a estas plantas. Além disso, foi estudada sua distribuição intra-planta, sua flutuação populacional em plantios comerciais de coqueiro e também as variações na expressão das enzimas oxidativas (POD e PPO) e o grau de peroxidação de lipídeos em genótipos de coqueiro, como respostas à alimentação deste ácaro. Foram verificados altos níveis populacionais do AVP em plantios comerciais de coqueiro e em outras plantas crescendo naturalmente no litoral na Venezuela. Em apenas oito espécies de Arecaceae, uma de Musaceae e uma de Strelitziaceae foram verificados todos os estágios de desenvolvimento do AVP, sugerindo que este se desenvolve e se reproduz nestas plantas. O ácaro fitoseídeo Amblyseius largoensis (Muma) foi o predador mais frequentemente associado com o AVP em todos os locais estudados. Maiores densidades do AVP foram observadas nas regiões mediana e basal das folhas coletadas nos estratos mediano e basal da copa da planta. Em 2010, os níveis populacionais do AVP foram mais elevados que em 2011, aparentemente em função dos níveis menores de precipitação naquele ano. O AVP conseguiu se desenvolver sobre as espécies de plantas ornamentais, mas não nas espécies de arecáceas nativas do Novo Mundo. Com relação às enzimas oxidativas, as atividades das POD, PPO e a peroxidação de lipídeos foram maiores em plantas infestadas dos cultivares Anão Amarelo da Malásia (AAM) e Gigante do Caribe (GC) quando comparadas com os respectivos controles. Além disso, maiores atividades de POD e PPO foram detectadas no cultivar AAM que no cultivar GC, tanto em plantas infestadas quando não infestadas. Em contraste, maior peroxidação de lipídeos foi verificada em plantas do cultivar GC infestadas. Estes resultados sugerem que provavelmente esses genótipos de coqueiro possuim mecanismos de resistência ao AVP, porem estudos complementares precisam ser realizados. / Occurrence of the red palm mite, Raoiella indica Hirst (Acari: Tenuipalpidae), was related in the New World in 2004 and since then this mite species has colonized several arecaceaous and musaceous plant species, but also ornamental species in the Caribbean Islands, Florida (USA), Venezuela, Brazil and Colombia. Since firstly reported, this mite species has provoked considerable economic losses in coconut in countries where it has been found thus raising more interest to know pest impact on plant species on which mite has been found. In order to know biological aspects of R. indica samplings were made to determine geographical distribution, and also host plants and natural enemies which are found with it. Pest biology was assessed in ornamental plants and also on palms species native to Neotropical region in order to evaluated potential to cause damage on these plant species. Besides intra-plant distribution and population fluctuation was evaluated in coconut commercial plots and also variations in oxidative enzyme expression (POD and PPO) and extent of lipid peroxidation in coconut genotypes as response to R. indica feeding. Higher population levels of RPM were verified in coconut commercial plots but also in naturally growing plants in the coastal line in Venezuela. All developmental stages of the RPM were verified only on eight Arecaceae species, one Musaceae and one Strelitziaceae species thus suggesting that mite is able to develop and reproduce on these plant species. Phytoseiid mite Amblyseius largoensis (Muma) was the most frequent predator species associated to the RPM in all of the sampling areas. Higher mite densities were observed in middle and basal portions from leaf collected from middle and basal canopy. In 2010, RPM population levels were higher than in 2011, probably as function to lower rainfall levels in that year. The RPM completed development on ornamental plant species but did not on arecaeous native to New World. In regard to oxidative enzymes, POD and PPO activities and lipid peroxidation were higher in infested plants from Malaysian Yellow Dwarf (MYD) and Caribbean Tall (CT) as compared to respective controls. Besides higher POD or PPO activities were detected in MYD cultivar than in CT both in infested or no infested plants. In contrast, higher lipid peroxidation was verified in infested CT cultivar. Our results suggest that probably these coconut genotypes exhibit resistance mechanism to the RPM, however more detailed studies are required.

No presente trabalho foram estudadas 8 espécies lenhosas dos gêneros Cinchona (C. amazonica Standl.), Croton (C. billbergianus Müll.Arg., C. floribundus Spreng., C. lechleri, Müell.Arg., C. matourensis Aubl., C. palanostigma Klotzsch) e Uncaria (U. guianensis (Aubl.) J.F. Gmel. e U. tomentosa (Willd. ex Roem. & Schult.) DC.) de interesse medicinal e ocorrentes no Estado do Acre, Brasil. Dessas plantas foram analisadas as características dendrológicas, a estrutura anatômica do lenho, sua distribuição geográfica e “status” de conservação. A pesquisa consistiu de visitas de campo a diferentes regiões do Estado, coleta de material botânico e do lenho das plantas, levantamento e estudo das exsicatas das espécies em herbários nacionais e internacionais da América do Sul, revisão bibliográfica das espécies na literatura e “sites” especializados, descrição dos parâmetros dendrológicos e da estrutura antômica do lenho das espécies em laboratório, possibilitando a identificação das espécies dos 3 gêneros. As características dendrológicas vegetativas das plantas mostraram variações, resultado das adaptações ao meio ambiente, da idade e de sua ampla distribuição geográfica. A estrutura anatomica do lenho foi mais distinta entre famílias (Euphorbiaceae e Rubiaceae) e gêneros (Cinchona, Croton, Uncaria) e menos nas espécies, constituindose em parâmetro importante e auxiliar na sua identificação. As plantas de Cinchona amazonica apresentaram baixa intensidade populacional, embora com ampla distribuição no Estado do Acre, em outros estados brasileiros e nos países amazônicos. No gênero Croton, as plantas de C.palanostigma mostraram distribuição quase pontual no Acre e extensa na Amazônia e menos ampla na América Latina; C. floribundus com ocorrência pontual no Acre, distribuição concentrada no Estado de São Paulo e em outros estados brasileiros e no Paraguai; C. matourensis encontram-se bem distribuídas no Acre e em outros estados brasileiros e países amazônicos, até o Panamá; C. lechleri ocorrem somente no sudeste do Estado do Acre, na Bolívia, Colômbia, Peru e Equador; C. billbergianus encontram-se bem distribuídas no Estado do Acre, escassa em outros estados amazônicos, ocorrendo em outros países da América Latina até o México. As plantas de Uncaria guianensis e U. tomentosa foram as de maior abundância no Estado do Acre e em toda a Amazônia brasileira, sendo U. tomentosa de menor abundância e distribuição muito ampla ocorrendo, inclusive, até a América Central. Com respeito ao “status” de conservação, as plantas de Croton billergianus, C. matourensis e Uncaria guianensis foram incluídas na categoria LC (comuns e abundantes ou fora de perigo), Cinchona amazonica, Croton lechleri e C. palanostigma em CR (perigo crítico), Uncaria tomentosa em VU (perigo a médio prazo) e Croton floribundus em DD (informação insuficiente). A presença destas espécies não foi constatada nas unidades de conservação do Estado do Acre e, no momento, as florestas onde ocorrem estão sendo exploradas para a extração da madeira, de fármacos e para a ampliação da fronteira agropecuária. Nos herbários das instituições de pesquisa e de ensino do Estado do Acre as coleções de plantas das espécies de Cinchona, Croton e Uncaria são escassas em comparação com as de outros Estados do Brasil e dos países visitados. / This research studied eight wood species of the genus Cinchona (C. amazonica Standl.), Croton (C. billbergianus Müll.Arg. C. floribundus Spreng.; C. lechleri, Müll.Arg.; C. matourensis Aubl. and C. palanostigma Klotzsch) and Uncaria (U. guianensis (Aubl.)J.F. Gmel. and U. tomentosa (Willd. ex Roem. & Schult.)DC.). All of them with medicinal interest, grown in the state of Acre (Brazil). The research consisted mainly in: field work in different regions of the state of Acre and botanical and plants collections, raising the exsiccates of the mentioned species in the most important national and international herbariums of South America, a wide bibliographical review concerning these species, dendrology description and the macro and microscopy description of the wood. The ve getative dendrological characteristics of these species showed variations with age adaptations and geographical distribution. The anatomy structures were different between families (Euphorbiaceae and Rubiaceae) and genus (Cinchona, Croton, Uncaria) and less within species. These results can be used for identification of these genus. In the order hand, this study shows that Cinchona amazonica had low distribution in Acre State, other Brazilian states and Amazonian countries. For Croton genus as C. palanostigma showed an almost punctual distribution in Acre, although had high distribution on the Amazon region and lowest on Latin America; C. floribundus with punctual occurrence on the Acre State and concentrated distribution in Sao Paulo State, other Brazilian States and in Paraguay; C. matourensis had high distribution in Acre, other Brazilian states and Amazonian countries, reaching up to Panama; C. lechleri grew only in the south east of Acre, Bolivia, Colombia, Peru and Ecuador; C. billbergianus was found well distributed in Acre, less abundant in other Amazon states and Latin countries and reaching up to Mexico. Uncaria guianensis and U. tomentosa were the most abundant species in Acre state and in all the Brazilian Amazon, and the U. tomentosa in Brazil can be considered less abundant, although with a wider distribution reaching inclusive the Central America. Concerning the conservation “status”, C billbergianus, C. matourensis and U. guianensis were included in the category LC (common and abundant or out of danger); Cinchona amazonica, Croton lechleri and C. palanostigma on CR (critical danger), Uncaria tomentosa on VU (medium term danger) and Croton floribundus on DD (insufficient information). One of the most important aspects to mention is that there were no evidence of any presence of these species in the conservation unites in the State of Acre, and in the forests where they occur. Also, they are cuttings for raw material for wood, pharmacological exploration and farm and cattle frontiers amplification.. This situation was verified in the State of Acre for the lower collection of plants of Cinchona, Croton and Uncaria in relation to other states in Brazil and in other countries visited.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-04-01T11:36:22Z No. of bitstreams: 1 thaysdeoliveiradias.pdf: 1461234 bytes, checksum: 9479b441e689c9ee5ebd5d297e617460 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-04-24T03:00:22Z (GMT) No. of bitstreams: 1 thaysdeoliveiradias.pdf: 1461234 bytes, checksum: 9479b441e689c9ee5ebd5d297e617460 (MD5) / Made available in DSpace on 2016-04-24T03:00:22Z (GMT). No. of bitstreams: 1 thaysdeoliveiradias.pdf: 1461234 bytes, checksum: 9479b441e689c9ee5ebd5d297e617460 (MD5) Previous issue date: 2013-02-28 / O objetivo deste trabalho foi realizar um levantamento malacológico e investigar a presença, distribuição e avaliar a possibilidade de infecção por Fasciola hepatica em moluscos da espécie Pseudosuccinea columella, em coleções hídricas na microrregião de Juiz de Fora, Minas Gerais, Brasil, nos anos de 2009, 2011 e 2012. O primeiro capítulo apresenta os resultados sobre a composição da malacofauna, com a lista de espécies encontradas e informações sobre a sua distribuição. Foram realizadas coletas em 22 localidades na microrregião de Juiz de Fora, sendo os moluscos coletados através de uma metodologia de coleta direta. Foram encontradas na microrregião de Juiz de Fora 9 espécies de gastrópodes: Melanoides tuberculatus (Müller, 1774) (Thiaridae); Biomphalaria tenagophila (d´Orbigny, 1835); (Planorbidae), Pseudosuccinea columella (Say, 1817) (Lymnaeidae); Stenophysa marmorata (Guilding, 1828), Haitia acuta (Draparnaud, 1805) e Afrophysa brasiliensis (Küster, 1844) (Physiidae); Pomacea sp. (Perry, 1810) (Ampullariidea), Gundlachia sp. (Pfeiffer, 1849) Ancylidae e o pulmonado estilomatóforo Omalonyx sp. (d´Orbigny, 1937) (Succineidae). Um total de 719 moluscos foram coletados, sendo que 29,6% H. acuta, 0,97% S. marmorata, 0,83% A. brasiliensis, 56,8% P. columella, 5,14% B. tenagophila, 5% Gundlachia sp., 0,13% Melanoides tuberculatus e 1,39% Pomacea sp. Dentre estas, quatro são espécies exóticas: M. tuberculatus, P. columella, S. marmorata e H. acuta. No segundo capítulo é registrada a ocorrência de S. marmorata e A. brasiliensis no município de Juiz de Fora, com informações sobre a distribuição e um estudo morfológico detalhado das espécies. O terceiro capítulo apresenta o estudo que teve por finalidade investigar a presença e distribuição e avaliar a possibilidade de infecção por F. hepatica em moluscos da espécie P. columella. As coletas foram realizadas em 22 ecossistemas aquáticos lóticos e lênticos. Foram coletados 409 espécimes em 04 dos 22 pontos de coleta que incluíram córregos, represas, lagos, lagoas e valas de irrigação. O estudo morfológico dos espécimes permitiu a identificação específica P. columella. A pesquisa por formas larvais de trematódeos foi realizada através da técnica de exposição à luz artificial. Nenhum molusco examinado estava infectado. A ocorrência da fasciolose está ligada à presença de moluscos do gênero Lymnaea, neste sentido, é de extrema importância a realização de estudos com o objetivo de monitorar as diferentes regiões do Brasil, onde haja a presença de hospedeiros intermediários e, consequentemente, o potencial para a instalação da doença. O presente trabalho constitui o primeiro estudo sobre a composição da malacofauna límnica na microrregião de Juiz de Fora, Minas Gerais. O levantamento da malacofauna límnica da região é de fundamental importância para o maior conhecimento da ocorrência e distribuição das espécies nativas, além do reconhecimento da presença e distribuição de espécies exóticas e hospedeiras de helmintos, servindo de ponto inicial para o desenvolvimento de estratégias de controle. / The aim of this study was to realize a malacological survey and to investigate the presence, distribution of Fasciola hepatica so as to evaluate the presence of infected individuals of Pseudosuccinea columella in water collections at the micro region of Juiz de Fora, Minas Gerais, Brazil, in the years 2009, 2011 and 2012. In the first chapter, results of species composition are presented, with a list of these species and information about its distribution. The collections were made in 22 localities, being the snails collected by direct collections. It were found 9 gastropod species in Juiz de Fora microregion: Melanoides tuberculatus (Müller, 1774) (Thiaridae); Biomphalaria tenagophila (d´Orbigny, 1835); (Planorbidae), Pseudosuccinea columella (Say, 1817) (Lymnaeidae); Stenophysa marmorata (Guilding, 1828), Haitia acuta (Draparnaud, 1805) e Afrophysa brasiliensis (Küster, 1844) (Physiidae); Pomacea sp. (Perry, 1810) (Ampullariidea), Gundlachia sp. (Pfeiffer, 1849) Ancylidae and the pulmonate stylommatophora Omalonyx sp. (d´Orbigny, 1937) (Succineidae). It were collected 719 snails, being 29,6% H. acuta, 0,97% S. marmorata, 0,83% A. brasiliensis, 56,8% P. columella, 5,14% B. tenagophila, 5% Gundlachia sp., 0,13% Melanoides tuberculatus and 1,39% Pomacea sp. Among these, four are alien species: M. tuberculatus, P. columella, S. marmorata and H. acuta. In the second chapter it was registered the occurrence of S. marmorata and A. brasiliensis in Juiz de Fora, with information on distribution and a detailed morphological study of the species. The third chapter presents a study that aimed to investigate the presence, distribution and to evaluate the possibility of infection by F. hepatica in the freshwater snail P. columella. The collections were realized in 22 in lotic and lentic aquatic ecossystems. It were collected 409 specimens in 04 of 22 collections points that comprised streams, dams, lakes, lagoons and irrigation ditches. The morphological studies of specimens allowed the identification of P. columella. The research of larval forms of trematodes was realized by exposure to artificial light. No infected snails were found. The occurrence of fasciolosis is related to the presence of snails of the genus Lymnaea, in this way, it is important to realize studies in order to monitoring different regions of Brazil were intermediate hosts are found, that are potential areas to the establishment of the disease. The present study is the first study of freshwater malacological composition in the microregion of Juiz de Fora, Minas Gerais. The survey of this fauna in this region is of fundamental importance to the knowledge of occurrence and distribution of native species, besides the recognition of the presence and distribution of native and alien species and helminth hosts, serving as threshold for the development of control strategies.

M.Sc. (Botany) / In South Africa, controlling and eradicating Azolla filiculoides and Eichhornia crassipes cost annually approximately US$ 60 million to the national budget. However, the success of these operations is mixed because invasive aquatic plants often spread very rapidly either before they are spotted or before decisions are taken to implement control actions. This limitation is further exacerbated by difficulties in determining the invasion potential of newly introduced or unknown aquatic plants, as well as difficulties inherent to species identification. Resolving these drawbacks requires pre-emptive actions such as identifying areas that are most vulnerable to invasion by alien plants. In this study, I first explore whether molecular technique such as DNA barcoding can be useful to: i) overcome potential limitation of morphology-based identification of invasive aquatic plants; and ii) establish successful control of these invasives. For this purpose, I tested the utility of official DNA barcodes (rbcLa + matK or core barcodes), trnH-psbA, and the core barcode + trnH-psbA to identify invasive aquatic plants of South Africa’s freshwaters. Second, I use the technique of ecological niche modeling to identify most vulnerable freshwater systems to species invasion under current and climatic conditions. My analysis indicates that the core barcodes and matK regions perform poorer compared to trnH-psbA, which provides 100% successful identification alone or in combination with the core barcodes. This study therefore validates trnH-psbA as single best DNA barcode for invasive alien aquatic plants of freshwater systems in South Africa. Using this DNA region in BLAST analysis to screen plants species sold in aquarium market in Johannesburg, I found surprisingly that some prohibited species are already in circulation in the market. These include Hydrilla verticillata, egeria densa, Myriophyllum spicatum, and Echinodorus cordifolius. Furthermore, based on climatic parameters, I explored the distribution of the "bad five" aquatic species in South Africa, i.e. the most damaging invaders of freshwater systems. I found distinct distribution potentials for these species under current climatic conditions. Overall, 38% of all South Africa’s dams occur in areas climatically vulnerable to the invasion by the bad five with the Western Cape Province being the most vulnerable. However, under predicted climate change scenario, I found evidence for contrasting shifts in species range: species such as Azolla filiculoides, Eichhornia crassipes, Salvinia molesta might increase their range by at most 2% whilst the ranges of Myriophyllum aquaticum and Pistia stratiotes might contract by at most 5%. This range contraction and expansion will result in some dams currently vulnerable to invasion becoming resilient whilst others that are currently resilient might become vulnerable owing to climate change. This result demonstrates not only the utility of DNA barcoding in implementing control measures, but also provides ways of prioritising control/management efforts.

Doctorat en Sciences / info:eu-repo/semantics/nonPublished

Berkheya Ehrh. is a genus of daisies in the tribe Arctotideae, subtribe Gorteriinae with over 80 species, most of which occur in southern Africa. This genus has centres of diversity associated with the montane regions of South Africa, including the Drakensberg Alpine Centre and Mpumalanga escarpment regions. Previous molecular and morphological studies indicate that Berkheya is paraphyletic. I present phylogenies based on nrDNA (ITS; Internal Transcribed Spacer) and cpDNA (psbA-trnH) sequence data analysed with Bayesian Inference and Parsimony. A phylogeny of combined cp- and nrDNA is also presented. These phylogenies are used to assess generic limits and to investigate the biogeographic patterns of Berkheya and its allies. The ITS phylogeny shows five well supported clades of Berkheya, two of which (Clades I and 2) are monophyletic summer rainfall region clades. Clades 3 to 5 are all paraphyletic winter rainfall clades with Cullumia occurring in the third clade, Cuspida occurring in the fourth and Didelta in Clade 5. Both psbA-trnH and combined phylogenies show concordance with the clade distribution shown in the ITS phylogeny. The ITS phylogeny was used to analyse correspondence with Roessler’s (1959) Series. It was found that the phylogeny showed considerable agreement with Roessler’s series, but B. bipinnatifida and B. spinosa of Series Speciosae may require some revision as well as taxa of monotypic series Cruciatae and Angustae. It is suggested that the latter series be merged with Cullumia species to form a single series. Some consideration should be taken to include Didelta species into Series Fruticosae as Didelta occurs in subclade 5b of Clade 5 with other Series Fruticosae taxa. Achene morphology was examined from species from each of the five clades to investigate the relationships of Berkheya and its allies, as well as to determine if there were any consistent achene features for each clade. The structure of surface cells on the fruit, the presence, absence and morphology of twin hairs as well as the structure of the pappus scales were found to be most useful in reflecting phylogenetic relationships within the clades. When compared with the clades of the ITS phylogeny, achene morphology showed consistent characters between taxa occurring in the same clades. As the most comprehensive study involving Berkheya, this phylogenenetic investigation was able to confirm that Berkheya is a paraphyletic genus with Didelta, Cullumia and Cuspida needing to be subsumed into Berkheya. An alternative classification is that taxa of Clade 5 could possibly be erected as an expanded Didelta, separate and sister to Berkheya.

It is currently hypothesised that the chokka squid (Loligo reynaudi) consist of a single stock. This was tested through a spatial comparison of the morphology of this species. Forty three morphometric characters were measured from 1079 chokka squid collected from three regions: the south coast of South Africa, the west coast of South Africa, and southern Angola. While no significant differences were found for the hard body parts, results from discriminant function analyses showed the soft body morphometric characters from each of the three regions differed, with an overall correct classification rate of 100% for males and 99% for females in all three regions. Due to the existing model being used to assess the resource currently being updated it was not feasible to apply this model to the area-disaggregated data from this study. Rather, the CPUE trends and catches from the area-disaggregated data were compared against those of the area-aggregated data, as a first attempt to discern any appreciable differences which would suggest the use of disaggregated data in future assessments. Both the trawl and jig CPUE trends from the area-disaggregated analysis differed only slightly from those of the area-aggregated data. Similarly, the spring and autumn biomass trends for the main spawning area (east of 22°E) followed the same trends as for the full area. It is therefore concluded that there is currently no need to assess the resource on an area-disaggregated basis.