Ph.D. / The declining marine fish catches and the increasing demand for farmed fresh water fishes are motivation for research and development of improved strains and techniques for the production of gynogenetic and triploid offspring of popular fresh water fishes ...

P. magnifica is an invasive freshwater bryozoan species which is native to the North America. The aim of this thesis is to ascertain the pace of the colonies' growth. The survey was carried out in three locations during twenty-one days in July 2018.

Arterial variants, defined as atypical presentations of anatomy including aberrant origin, course, and branching pattern, are important to be aware of because of their effects in the clinical setting as well as their possible link to pathology. Much research has already been done focusing on specific arterial variants in a specific region in the body. However, more research is needed to determine if there is a relationship between arterial variants in different regions of the body. The purpose of this study is to examine the whole-body arterial system of body donors in order to assess if there is a relationship between the presence of arterial variants in one region of the body to the other. The entire arterial system of twenty-five formalin fixed body donors was examined for the presence of arterial variants. The data was separated into two main categories, central variants (e.g. arch of the aorta, unpaired abdominal aortic branches) and peripheral variants (e.g. upper and lower extremities). The relationship between the central and peripheral variants was determined using quantitative observation, specifically, by examining the percent frequency of cases where arterial variants were co-occurring. Of the body donors examined, all were found to have at least one arterial variant, with an average of 8.7 variants per body. Arterial variants were most commonly found in the foregut with prevalence of 80%, the midgut (68%), left subclavian (60%), right upper extremity (52%), and the left upper extremity (48%). Of the central arterial variants, a percent frequency of 20% was found for the arch of the aorta, 20% for the coronary artery, 12% for the hindgut, 28% for the right renal, and 28% for the left renal. For the peripheral variants, the percent frequencies were as follows: brain variants were 4%, right carotid 8%, left carotid 0%, right subclavian 28%, left upper extremity 40%, right suprarenal 24%, left suprarenal 12%, right phrenic 24%, left phrenic 12%, gonadal 4%, right iliac 40%, left iliac 32%, and right lower extremity 40%. Examination of the relationship between central variants and peripheral variants reveals that the most common arterial variants to occur in tandem in the sample were those of the variant foregut with variants of the left subclavian artery (52% of cases), the upper and lower extremities (36-44% and 40-44% of cases, respectively), and the right iliac artery (36% of cases). The most common central arterial variants to co-occur were the variants of the foregut and midgut observed in 64% of cases. The frequency of cases involving normal central anatomy and variant peripheral anatomy indicates that vascular variants in the periphery are likely unrelated to variants in the central body cavities. However, it does seem like there are “hot spots” for arterial variants to occur, including the foregut, midgut left subclavian artery, right and left upper extremities, the right iliac artery, and the right and left lower extremities. Although there was no discernable pattern found between vascular variants in the present study, that does not preclude the possibility that there is a significant relationship between certain vascular variants. Either way, the high prevalence of cases with multiple arterial variations suggests that they may be more likely to occur than previously thought.

A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of requirements for the degree of Master of Science. Johannesburg, 2015. / Thrinaxodon liorhinus, a cynodont that has been of captivating importance in the evolution of therapsids, is one of the best known transitional fossil taxa from non-mammaliaform cynodonts to mammals. The species is abundant in the South African Karoo Basin and is one of the best represented taxa immediately after the Permian-Triassic mass extinction. One of the key adaptive characteristics that may have aided in their survival was fossorialism. Numerous fossils of Thrinaxodon have been found in burrows or in a curled-up position, which has provided important circumstantial evidence for the formalization of the hypothesis of Thrinaxodon as a burrower. However, finding a fossil inside a burrow or even in a curled-up position only provides firm evidence for burrow use, not for burrow creation. Direct evidence for burrowing capability can come from the understanding of the functional morphology of Thrinaxodon limbs. The present study investigates internal and external structure of the Thrinaxodon forelimb, a variety of reptiles characterized by different behavioural patterns, and other cynodonts in order to advance present knowledge about the functional morphology of the transitional phase cynodont. The study uses Geometric Morphometric analyses, forelimb metric indices, torsion and cortical thickness of humeri in order to determine the extent to which, the Thrinaxodon forelimb functionally and structurally resembles that of a fossorial mammal versus a digging reptile. Results of the study tease apart the extent to which the Thrinaxodon forelimb illustrates modifications due to gait (e.g., sprawling versus semi-sprawling) versus a fossorial lifestyle. This would indicate that Thrinaxodon retained the reptilian skeletal configuration and adapted a posture that had begun to resemble parasagittal more than sprawling or semi-sprawling gait. Nonetheless, Thrinaxodon exhibits forelimb structural similarities to digging species, whether mammals or reptiles.

The genus Kannemeyeria is one of the most important and distinctive taxa of the Triassic dicynodonts. It became the first Triassic dicynodont known to science, and thus forms the benchmark for the comparison of the evolution and morphology of other Triassic dicynodonts. An understanding of this genus forms an integral part of the biozonation of the Beaufort Group, and is pivotal in influencing the interpretation of the evolution, physiology and phylogenetic relationships of the Triassic dicynodonts. This study focuses on the detailed cranial morphology and relationships of the Kannemeyeria, and uses a rigorous morphological investigation as the basis for a meaningful elucidation of the functional and thus physiological aspects of this dicynodont. The descriptions demonstrate that variations related to the skull size, distortion or naturally occurring variation within the genus allow for the synonymy of the formerly recognised species K. latifrons Broom (1898; 1913), K. erithrea Haughton (1915) and K. wilsoni Broom (1937). This conclusion is further supported by the allometric analysis which cannot distinguish the variation observed in the holotypes with that occurring naturally within a growth series. Apart from the large specimen, the other smaller individuals are accommodated in the genus as different ontogenetic stages of the growth series represented by K. simocephalus Weithofer (1888). Several allometric variables show unusual patterns of development, indicating that Kannemeyeria can be subdivided into ontological classes, as juvenile and adult forms, separated from each other by a particular level of development. An age-related threshold level is suggested, and considered to represent an animal reaching sexual maturity. It is consequently proposed that the Kannemeyeria population was, at an age-related level, subdivided into sexually mature and immature groups but remained ecologically homogeneous. Both the descriptions and the allometric analysis of the species K. cristarhynchus Keyser & Cruickshank (1979) clearly indicate that it does not conform to the growth series of K. simocephalus and thus the differences observed between these two taxa are not constrained to size increases. Consequently, the recognition of the species K. cristarhynchus is considered valid. From the observations of the cranial morphology, tested using an allometric analysis, generic and specific diagnoses are constructed for Kannemeyeria and its two African species. Several features of Kannemeyeria are discussed in a functional context. A corrugated hom-covered snout and large caniniform processes are considered to be associated with defence and posturing behaviour. Several features of the braincase also suggest herding behaviour. Kannemeyeria also has a slightly different occipital musculature arrangement than that proposed for many other dicynodonts. Most Kannemeyeria cranial features are related to its masticatory function. From the analysis of masticatory cycle it is clear that the jaw action is described via a single pivot-point, which in Kannemeyeria approached the original, primitive position of the jaw hinge. The vertical orientation of the articulation and this pivot-point ensured that the muscle action during second phase of mastication produced an upward crushing and grinding action instead of the typical fore-and-aft motion of many other dicynodonts. It also meant that the muscle force was at their maximum, and little or no energy was lost to translation of the moment arm at the jaw articulation. Consequently, the Kannemeyeria masticatory cycle was both highly effective and extremely efficient. The morphology, and resultant physiology, of Kannemeyeria skull is considered to represent the innovative foundation for much of the success of many of the later Triassic dicynodonts.

Os pica-paus (família Picidae) são um grupo bem definido e caracterizado por adaptações ligadas ao modo de vida arborícola como membros posteriores próprios para escalada de apoios verticais, crânio e maxilas robustos utilizados para golpear madeira rapidamente e com força e cauda com penas rígidas utilizadas como apoio na escalada. Dentro da família, entretanto, existem espécies que não só apresentam hábito terrícola como algumas em especial que abandonam totalmente o hábito arborícola. O gênero com maior incidência desses casos é Colaptes Vigors, 1825, onde todos os representantes estão associados com a alimentação especializada em formigas e cupins e suas larvas e as linhagens exclusivamente terrícolas nidificam em barrancos ou buracos no chão. Além dele, existe o gênero monotípico africano Geocolaptes Gmelin, 1788, que apresenta as mesmas características de habitat mas relações filogenéticas distante. O objetivo deste trabalho foi o de analisar a relação entre as formas dos exemplares em busca de similaridades e diferenças relacionadas ao hábito e comportamento das linhagens e a possível independência do surgimento dessas alterações na filogenia do grupo. Foram analisados 49 exemplares de esqueleto pertencentes aos dois gêneros com representantes terrícolas bem como exemplares dos gêneros Dryocopus e Celeus como comparação a linhagens adaptadas ao hábito arborícola, depositados na coleção do MZUSP e em coleções estrangeiras. O tratamento dos dados por meio de Análise de Componente Principal (PCA) mostrou correlação entre o hábito de vida das linhagens e atributos do crânio (altura do crânio, formato do bico e tamanho e posicionamento das narinas) e do pós-crânio (tamanho e formato do pigóstilo e tamanho da quilha). É possível que estas alterações na forma das linhagens tenham duas pressões distintas, a exploração de um recurso diferente na alimentação (formigas e cupins) e a alteração nos modos de locomoção dos indivíduos (pigóstilo para o apoio das rectrizes na escalada e quilha no esforço de decolagem a partir do chão). Os resultados sugerem a possibilidade dessas adaptações terem surgido independentemente mas gerado resultados extremamente semelhantes em forma, mas também demonstram a necessidade de um estudo incorporando mais táxons para uma comparação mais representativa / Woodpeckers (family Picidae) are a well-defined group, traditionally characterized by their unique morphological specializations for climbing and excavating in trees, like posterior limbs and the tail adapted for support and a robust cranium and beak for hammering on wood. Among the species in the family, however, there are not only some that stray from this highly specialized behavior and develop ground-based behavior, but also a few that completely abandon trees. The genus with most of these cases, Colaptes Vigors, 1825, contains species that specialize in feeding on ants ant termites and their larvae, building nests in banks, holes in the ground or even termite hills. Besides them, the monotipical African genus Geocolaptes Gmelin, 1788 shows the same feeding and nesting habits but is much more distantly related. This work aims at analyzing relations between the shapes of the species\' skeletons and looking for similarities and differences that correlated with their habitats and behavior and whether or not the similar solutions occurred independently throughout the family\'s evolutionary history. 49 skeleton specimens were utilized, belonging to the two ground dwelling and the Dryocopus and Celeus genera. Principal Component Analysis showed correlation between feeding and nesting habits and several measures of the skull (skull height, beak shape and nostrils\' shape and positioning) and postcrania (size and shape of the pygostyle and size of the keel). It is a possibility that these changes in shape derive from two distinct selective pressures: the exploration of a different food source (ants and termites) and the change in the way the organisms move (pygostyle as a support in climbing and the keel relating to the strain of taking off). The results suggest that these adaptations came about independently but generated extremely similar shapes, while also demonstrating the need for further study with the inclusion of more taxa for a more representative comparison

A família Simaroubaceae constitui um grupo com grande potencial de estudo. Com distribuição essencialmente tropical, é considerado um grupo relativamente pequeno dentro da Ordem Sapindales e monofilético, mas morfologicamente diversificado. Apenas Engler, no final do século XIX, estudou detalhadamente a família no Brasil como um todo, e desde então as adições ao conhecimento do grupo têm ocorrido de forma gradual e fragmentada. Esta dissertação aborda estudos estruturais de espécies do gênero Simaba, o maior da família, analisando a estrutura foliolar dos representantes de todas as suas seções, Simaba sect. Floribundae Engl., S. sect. Grandiflorae Engl. e S. sect. Tenuiflorae Engl., a fim de selecionar caracteres morfológicos e anatômicos para auxiliar os trabalhos de taxonomia deste gênero, que não recebe tratamento desde uma revisão taxonômica publicada em 1983. Além do estudo das estruturas vegetativas, neste trabalho documentamos as estruturas florais, que possuem com poucos registros de estudo na literatura do grupo, por meio de análise comparativa da morfologia e anatomia das flores de espécies pertencentes às seções S. sect. Floribundae e S. Sect. Grandiflorae, tradicionalmente distintas principalmente pelo tamanho da flor e grau de fusão do apêndice estaminal ao longo do filete, mas com grande semelhança morfológica entre si. Além de apresentar as descrições e ilustrações das características estruturais vegetativas e reprodutivas encontradas, investigamos a existência de atributos florais ainda não reportados no grupo, provendo um panorama de caracteres foliares e florais informativos para subsidiar a resolução dos problemas taxonômicos existentes no gênero e visando melhor delimitação entre as espécies que exibem grande semelhança morfológica, mesmo pertencendo ao mesmo grupo. / The Simaroubaceae family is a group with great potential for study. With essentially tropical distribution, it is considered a relatively small group within the Order Sapindales and monophyletic, but morphologically diverse. Only Engler, in the late nineteenth century, studied in detail the family in Brazil, and since then the additions to the knowledge of the group have taken place gradually. This dissertation deals with structural studies on the largest genus of the family Simaba, analyzing the leaflet structure of representatives of all its sections, Simaba sect. Floribundae Engl., S. sect. Grandiflorae Engl. and S. sect. Tenuiflorae Engl., we select morphological and anatomical characters for this genus, which does not receive taxonomic treatment since 1983. In addition to the study of vegetative structures, we documented floral structures of selected Simaba species, which have few study records in the group\'s literature. Through a comparative analysis of the morphology and anatomy of flower, we studied species belonging to sections S. sect. Floribundae and S. sect. Grandiflorae, traditionally distinguished mainly by flower size and degree of fusion of stamen appendages, but with some morphological similarity. In addition to presenting the descriptions and illustrations of the vegetative and reproductive structural features, we investigate the existence of floral traits not yet reported for the group. We also provide an overview of informative leaf and floral characters that support the resolution of existing taxonomic problems in the genus and to assist delimitation among species.

O gênero Centroscymnus Barboza du Bocage & Britto-Capello, 1864 compreende um grupo de tubarões de profundidade elevada, distribuídos por praticamente todos os oceanos. Esse gênero contém duas espécies, Centroscymnus coelolepis e Centroscymnus owstonii, ambas reportadas com ampla distribuição mundial; entretanto, foram originalmente descritas no Atlântico Oriental e no Pacífico Ocidental, respectivamente. O presente estudo examinou espécimes de praticamente todos os oceanos e concluiu que ambas espécies de Centroscymnus são válidas e, de fato, ocorrem de forma simpátrica com uma distribuição mundial. Centroscymnus coelolepis e Centroscymnus owstonii diferenciam-se por características dos dentículos dérmicos e caracteres esqueléticos, como a forma do rostro do neurocranium, arranjo das cartilagens das nadadeiras dorsais e forma das cartilagens do clásper. O gênero Centroscymnus é definido dos demais gêneros da família Somniosidae por apresentar dentículos démicos com lâminas dorsais lisas, no tronco e cauda de adultos, sem cristas longitudinais e pela forma retangular do rostro, sem projeções ou expansões. Este estudo ainda definiu os demais gêneros de Somniosidae e apresentou algumas evidências morfológicas que podem indicar sobre o inter-relacionamento nas espécies dessa família. / The genus Centroscymnus Barboza du Bocage & Britto-Capello, 1864 comprises a group of deep-water sharks, with worldwide occurrences in almost all oceans. This genus contains two species, Centroscymnus coelolepis and Centroscymnus owstonii, both with worldwide distribution either, however, they were originally described from Northeastern Atlantic and Northwestern Pacific, respectivelly. The present study examined specimens from almost all oceans and concluded that both species of Centroscymnus are valid and, indeed, have sympatric occorrences with a worldwide distribution. Centroscymnus coelolepis e Centroscymnus owstonii are distinguished by features in dermal denticles and skeleton, such as the shape of the rostro in neurocranium, arrangement of dorsal fins cartilages and the shape of clasper cartilages. The genus Centroscymnus is recognized from the remainder genera of Family Somniosidae by presenting dermal denticles with smooth surface of dorsal blades on trunk and tail of adults, without longitudinal ridges, and by a rectangular shape of rostro, without projections and expansions of any sort. This study also defined the remainder genera of Somniosidae, and presented some morphological evidences that might indicate the interrelationship within the species of this Family.

A subfamília Chauliognathinae Champion, 1914 é dividida em duas tribos: Chauliognathini LeConte, 1861 e Ichthyurini Champion, 1915. Na classificação de Miskimen (1961) Chauliognathini é formada por espécies que possuem élitros longos, recobrindo totalmente ou a maior parte do abdômen, enquanto nas espécies de Ichthyurini os élitros são muito curtos, expondo as asas e os tergitos abdominais. Em uma classificação alternativa, Magis & Wittmer (1974) propõem que as tribos sejam definidas principalmente com base em caracteres dos abdomens e genitálias dos machos. Nessa proposta, parte dos gêneros de Ichthyurini foi transferida para Chauliognathini. No entanto, uma análise cladística com o objetivo de testar a monofilia de Chauliognathini sensu Magis & Wittmer indicou que este não é monofilético, recuperando os grupos conforme a proposta de Miskimen (Biffi 2012). A classificação dos gêneros de Ichthyurini está relativamente bem resolvida, com quase todos os gêneros revisados. Por outro lado, a taxonomia de Chauliognathini é caótica, com poucos gêneros que não representam suficientemente a grande diversidade morfológica do grupo. As cerca de 900 espécies e subespécies estão alocadas principalmente em um único gênero, Chauliognathus Hentz, 1830, cuja definição pouco precisa abrange todas as espécies de Chauliognathini. É apresentada uma nova proposta de homologias para os caracteres do edeago da subfamília Chauliognathinae, principal estrutura utilizada por alguns autores para delimitar as tribos e gêneros. Em seguida, é proposta uma análise cladística da tribo Chauliognathini com o objetivo de elucidar o posicionamento filogenético de suas espécies e apresentar caracteres que possam sustentar uma nova classificação dos gêneros. Foram amostradas espécies representantes da grande diversidade morfológica e da ampla distribuição geográfica, incluindo as espécies-tipo de todos os gêneros e subgêneros. Os resultados confirmam a monofilia de Chauliognathini e Ichthyurini como grupos-irmãos, conforme a proposta de Miskimen (1961). São discutidas as possibilidades de redefinição ou proposição de novos gêneros, com a redistribuição das espécies. Por fim, como um primeiro passo nos futuros trabalhos de revisões dos gêneros da tribo, é apresentada uma revisão taxonômica de Microdaiphron Pic, 1926. Dez espécies são reconhecidas como válidas, sendo duas novas, e 23 espécies ou subespécies são propostos como sinônimos. São apresentadas redescrições, ilustrações e um mapa de distribuição para todas as espécies / The subfamily Chauliognathini Champion, 1914 is composed of two tribes: Chauliognathini LeConte, 1861 e Ichthyurini Champion, 1915. In Miskimen\'s (1961) classification the species of each tribe differ in terms of the length of elytra, which may are long, covering the abdomen (Chauliognathini) or very short, exposing the wings and abdominal tergites (Ichthyurini). Alternatively, Magis & Wittmer (1974) proposed that the tribes should be defined based on characters of the abdomen and genitalia of males. In this proposal, part of the Ichthyurini genera was transferred to Chauliognathini. However, a cladistic analysis conducted in order to test the monophyly of Chauliognathini sensu Magis & Wittmer indicated that the group is not monophyletic, recovering the groups according to Miskimen\'s proposal (Biffi 2012). The classification of the genera in Ichthyurini is reliable, with taxonomic revisions available for most of them. However, the taxonomy of Chauliognathini is chaotic, with few genera that do not represent the group\'s morphological diversity accordingly. The approximately 900 species and subspecies are mainly allocated in a single genus, Chauliognathus Hentz, 1830, whose imprecise definition covers all the species of Chauliognathini. A new proposal of homologies for the aedeagus of Chauliognathinae is presented. This is the main structure used by some authors to delimit the tribes and genera. Then, a cladistic analysis of Chauliognathini is proposed in order to verify the phylogenetic positioning of its species and to present morphological characters that may support new classifications for the genera. Species representative of the great morphological diversity and the wide geographic distribution were sampled, including the type species of all genera and subgenera. The results confirm the monophyly of Chauliognathini and Ichthyurini as sister groups, according to Miskimen\'s proposal. We discuss the possibilities of redefining or proposing new genera, with a redistribution of species. Finally, a taxonomic revision of Microdaiphron Pic, 1926, is presented. Ten species are recognized as valid, two of them proposed as new species, and 23 species or subspecies are proposed as synonyms. Redescriptions, illustrations and a distribution map are presented for all species

O estudo objetivou avaliar a resistência da união de sistemas adesivos aplicados ao esmalte, bem como a morfologia do substrato condicionado e a qualidade da interface de união formada. Após o esmalte das superfícies lisas de molares receberem profilaxia com pedrapomes, abrasão por lixa ou desgaste por ponta de diamante, foram aplicados Scotchbond Multi-Purpose Plus (SBMP), Single Bond (SB), Clearfil SE Bond (CSE); OptiBond Solo Plus Self-Etch (OP) e Tyrian Self Priming Etching (TY). Os semidentes ?restaurados? com resina Filtek Z250 foram armazenados em água deionizada (24h/37°C), secionados no formato de paralelogramo (área transversal aproximada de 0,8 mm2), aleatorizados em grupos (24h, 6 e 12 meses de armazenagem), e testados em microtração (0,5mm/min). Os valores médios de resistência da união (MPa) foram tratados por métodos de ANOVA e Tukey. Os resultados não mostraram diferenças significativas para os fatores Tratamento, Armazenagem, nem para as interações..Porém, houve diferença significante para o fator Adesivo (p<0,05). Os padrões morfológicos do esmalte obtidos após o uso do agente condicionante dos sistemas SBMP e SB não foram influenciados pelo Tratamento. Os fatores Adesivo e Tratamento influenciaram no padrão dos sistemas CSE, OP e TY. Não foram observadas fendas nas interfaces dos sistemas SBMP e SB, independente dos outros fatores. .Os sistemas OP e TY mostraram fendas em todas as condições, e o CSE após 12 meses no esmalte abrasionado por lixa. Com base nos resultados, conclui-se que o desempenho dos sistemas adesivos estudados está vinculado mais às características dos produtos do que ao tratamento realizado no esmalte ou armazenagem. / This study aimed to evaluate the resin-enamel bond strength, the etching pattern and the bonded interfaces provided by self-etch systems by means of scanning electron microscopy. The following adhesives systems (Scotchbond Multi-Purpose Plus [SBMP], Single Bond [SB], Clearfil SE Bond [CSE]; OptiBond Solo Plus Self-Etch [OP] or Tyrian Self Priming Etching [TY] were applied to sound enamel (after tooth prophylaxis), SiC paper or diamond bur-treated enamel. Resin composite buil-dups (Filtek Z250) were bonded to the enamel surfaces. After storage in water (24h/37°C), the bonded samples were sectioned into beams (0.8mm2), randomly assigned into subgroups (24h, 6 and 12 months) and subjected to microtensile bond strength test (0.5 mm/min). The data was analyzed by ANOVA and Tukey?s test. The main factors enamel Treatment and Storage as well as the interactions were not statistically significant. Significant differences were observed only for the main factor Adhesive (p<0.05). The Treatment did not affect the etching pattern of SBMP and SB; for CSE, OP and TY the morphology varied with the Treatment and Adhesive system. Gaps were not observed in the interfaces bonded with SBMP and SB, regardless of the Storage and Treatment. The adhesive CSE showed gaps after 12 months of storage for SiC paper, while this finding was observed for OP and TY in all conditions. Based on the results of the present investigation, it was concluded that the performance of some adhesive systems is influenced by the material´s composition instead of surface treatment or storage.