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Vertebrate brain size is remarkably variable at all taxonomic levels. Brains of mammals forexample, range from 0.1 gram in small bats (Chiroptera) to about 8-9 kilos in Sperm whales(Physeter macrocephalus). But what does this variation in size really mean? The link between brainsize and cognition is debated due to, for instance the difficulties of comparing cognitive ability indifferent species. A large number of comparative studies continue to provide information aboutcorrelations found both within and between species. The relative size of the brain is an example of apopular measurement that correlates with cognitive ability. But to date, no experimental studieshave yielded any proof causality between relative brain size and cognitive ability. Here I usedguppies selected for either large or small relative brain size to investigate differences in cognitiveperformance of a quantity discrimination task. The results from this experiment provideexperimental evidence that relative brain size is important for cognitive ability, and that a differencein cognitive ability could be obtained already after two generations of selection experiments onrelative brain size in a vertebrate. / Artificial Selection on Relative Brain Size in the Guppy Reveals Costs and benefits of Evolving a Larger Brain

The Trinidadian guppy, Poecilia reticulata, is a tropical freshwater fish with a long history as a model species for the study of evolution and adaptation to changing environments. The guppy is widespread in Trinidad, and many rivers on the island are host to multiple populations subject to varying levels of predation. Population structure in the guppy is influenced by several factors, including colonization history, presence or absence of barrier waterfalls within rivers, and both documented and accidental human-mediated introduction events. This study used genetic data from both microsatellite markers and mtDNA to investigate guppy population structure in 25 rivers and lakes across Trinidad and Tobago, with particular focus on the north shore Marianne and Paria Rivers. Most sites were located in the Northern Range Mountains of northern Trinidad, where rivers are divided into three major aquatic areas – the Caroni drainage, the Oropouche drainage, and the north shore. Results show a deep genetic divide between populations in the west-flowing Caroni drainage and those in the east-flowing Oropouche drainage, likely due to the colonization of these two drainages from two separate branches of the Orinoco, a large river located on the South American mainland. On Trinidad’s north shore, guppies collected in rivers on the western side of the island appeared to be genetically related to Caroni drainage guppies, while those in rivers on the eastern side of the north shore were predominantly related to Oropouche drainage guppies but showed evidence of admixture from the Caroni. Detailed study of Marianne and Paria River guppy populations showed downstream-biased gene flow in both rivers, with waterfalls in the Marianne limiting the movement of guppies in that river. Evidence of migration between the Marianne and Paria River watersheds was also found at two separate locations.

Made available in DSpace on 2016-08-10T10:31:03Z (GMT). No. of bitstreams: 1 SERGIO CORTES PAIVA.pdf: 795523 bytes, checksum: 516cf579af289fb7d528d54feea3847d (MD5) Previous issue date: 2012-02-07 / The ornamental aquaculture in the world is an activity of economic and social importance since it can be conducted under family, generating income and serving as an option to keep the population in the rural areas. The cultivation of ornamental fish is considered one of the most profitable sectors of Brazilian fish. The Guppy is an omnivore and teleost ornamental fish originating in Central America. This is one of the best-selling fish in the world followed by Kinguios. One of the characteristics of the Guppy sexual dimorphism is present. The Guppies born with about 6mm long. There are several factors that affect the growth rate of fish, such as temperature, pH, ammonia levels, dissolved oxygen in water, power, density, and genetics. This work aims to establish morphometric growth curves based on age for the Guppy, using - if different nonlinear models. The study was conducted in the Research Lab and Production of Aquatic Organisms (LAPO), located at Campus II of the Pontifical Catholic University of Goiás (PUC - GO) in the period from February 11 to June 21, 2011. We used 128 fish species Poecilia reticulata. Were made during the trial period 64 randomized trials, with a total of 128 fish Guppy, and 2 individuals / sample of each box. For morphometric measurements were made of the head length (CCAB), standard length (CP), Height (AND) and width (NLD). For each measure and reason morphometric growth curves were estimated using the roles of Von Bertalanffy, Richards, Brody, Gompertz and Logistics. The correlation between standard length, head length, width and height taken on the dorsal fin is high and Meaningful. The models of Gompertz, Brody and Bertalanffy were the ones that best described the growth of morphometric Guppies. / A aquicultura ornamental no mundo é uma atividade de importância econômica e social uma vez que pode ser conduzida em regime familiar, gerando renda e servindo como opção para manter a população rural no campo. O cultivo de peixes ornamentais é considerado hoje um dos setores mais lucrativos da piscicultura brasileira. O Guppy é um peixe ornamental teleósteo e onívoro originário da América Central. Este é um dos peixes mais vendidos no mundo seguido pelos kinguios. Uma das características do Guppy é apresentar dimorfismo sexual. Os Guppys nascem com aproximadamente 6mm de comprimento. Existem vários fatores que interferem na taxa de crescimento de peixes, tais como temperatura, pH, níveis de amônia, oxigênio dissolvido na água , alimentação, densidade e genética. O presente trabalho tem o objetivo de estabelecer curvas de crescimento morfométrico em função da idade para o Guppy, utilizando - se diferentes modelos não lineares. O estudo foi realizado no Laboratório de Pesquisa e Produção de Organismos Aquáticos (LAPOA), localizado no Campus II da Pontifícia Católica de Goiás (PUC GO), no período de 11 de fevereiro a 21 de junho de 2011. Foram utilizados 128 peixes da espécie Poecilia reticulata. Foram realizados durante o período experimental 64 amostragens aleatórias, com o total de 128 peixes Guppy, sendo 2 indivíduos/ amostragem de cada caixa. Para a avaliação morfométrica foram feitos medidas do comprimento da cabeça (CCAB), comprimento padrão (CP), Altura (AND) e Largura (LND). Para cada medida e razão morfométrica foram estimadas curvas de crescimento utilizando-se as funções de Von Bertalanffy, Richards, Brody, Gompertz e Logística. A correlação entre Comprimento Padrão, Comprimento da Cabeça, Largura e Altura tomadas à frente da nadadeira dorsal são altas e significativas. Os modelos de Gompertz, Brody e Bertalanffy foram os que melhor descreveram o crescimento morfométrico dos Guppies.

Submitted by Liliane Ferreira (ljuvencia30@gmail.com) on 2018-06-27T14:01:23Z No. of bitstreams: 2 Dissertação - Gabriel Qualhato - 2018.pdf: 4517101 bytes, checksum: 7e23af60d803b2f275d7d9babce3cc73 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-06-28T10:51:30Z (GMT) No. of bitstreams: 2 Dissertação - Gabriel Qualhato - 2018.pdf: 4517101 bytes, checksum: 7e23af60d803b2f275d7d9babce3cc73 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-06-28T10:51:30Z (GMT). No. of bitstreams: 2 Dissertação - Gabriel Qualhato - 2018.pdf: 4517101 bytes, checksum: 7e23af60d803b2f275d7d9babce3cc73 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-02-28 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / The environmental risk of nanomaterials (NMs) designed and used in nanoremediation process is of emerging concern, but their ecotoxilogical effects to aquatic organism remains unclear. In this present study, the citrate-coated (maghemite) nanoparticles (IONPs) were synthesized and its genotoxic, mutagenic, the melanomacrophage centers (MMC) response and hepatic histopathological biomarkers were investigated in female guppy. Fish were exposed to IONPs at environmentally relevant iron concentration (0.3 mg L-1) during 21 days and the animals were collected at the beginning of the experiment and after 3, 7, 14 and 21 days of exposure. The genotoxicity and mutagenicity were evaluated in terms of DNA damage (comet assay), micronucleus (MN) test, erythrocyte nuclear abnormalities (ENA) frequency and the liver were dissected and fixed dehydrated through increasing ethanol gradient, immersed in xylene PA, embedded in paraffin, performed of liver sections (5 μm thick) (3 sections per animal) in the microtome, stained by Mallory’s Trichrome and H. E. and analyzed. Results showed differential genotoxic and mutagenic effects of IONPs in the P. reticulata according to exposure time. The IONP induced DNA damage in P. reticulata after acute (3 and 7 days) and long-term exposure (14 and 21 days), while the mutagenic effects were observed only after long-term exposure. The DNA damage and the total ENA frequency increase linearly over the exposure time, indicating a higher induction rate of clastogenic and aneugenic effects in P. reticulata erythrocytes after long-term exposure to IONPs. Guppies exposed to IONPs showed increasing in the number, area and perimeter of MMC when compared to the unexposed ones, especially after 7 days of exposure. The results showed an increase in the frequency of histopathological changes in fish after the 7 days of exposure to IONPs, such micro- and macro-vesicular steatosis, melanomacrophage aggregates, exudate and haemorrhagic foci. The acute (3 and 7 days) and long-term (14 and 21 days) exposure of P. reticulata to IONPs induced high histopathological indexes associated with circulatory disorders and inflammatory responses. Results indicated that blood system and liver tissue of P. reticulata are excellent target organs to studies the ecotoxicity of IONPs. Confirming that P. reticulata is a biomonitor specie indicated for studies of ecotoxicity of IONPs. / O risco ambiental dos nanomateriais projetados e utilizados para nanoremediação se mostram hoje de grande interesse econômico e ambiental, mas seus efeitos ecotóxicológicos para os organismos aquáticos ainda permanecem obscuros. Neste presente estudo, as nanopartículas de oxido de ferro funcionalizadas com citrato (maghemita) (NOFs) foram sintetizadas e seus efeitos genotóxicos, mutagênicos, e histopatológicos foram investigados em fêmeas de Poecilia reticulata. Os peixes foram expostos a maghemita em concentrações de ferro ambientalmente relevantes (0,3 mg.L-1) durante 21 dias e os animais foram coletados no início do experimento e após 3, 7, 14 e 21 dias de exposição. A genotoxicidade e a mutagenicidade foram avaliadas por meio do dano causado ao DNA (Ensaio cometa), o teste do micronúcleo (MN) e anormalidades nucleares de eritrócitos (ANE) avaliaram o potencial mutagênico. Os fígados foram dissecados, fixados, desidratados em etanol, imersos em xilol, embebidos em parafina, e seccionados com 5 μm de espessura, os cortes corados em H.E. e Tricrômico de Mallory foram analisados e obtidos dados histomorfométricos. Os resultados mostraram efeitos genotóxicos e mutagênicos diferenciais das NOFs em P. reticulata de acordo com o tempo de exposição. As NOFs induziram danos ao DNA após exposição aguda (3 e 7 dias) e de longo prazo (14 e 21 dias), enquanto os efeitos mutagênicos foram observados somente para a exposição prolongada. O dano no DNA e a frequência total de ANE aumentaram linearmente ao longo do tempo de exposição, indicando uma maior taxa de indução de efeitos clastogênicos e aneugênicos em eritrócitos de P. reticulata após exposição prolongada a NOFs. Os guppies expostos também mostraram aumento do número, área e perímetro dos MMC quando comparados ao grupo controle, especialmente após 7 dias de exposição. Os resultados mostraram um aumento na frequência de alterações histopatológicas em peixes após os 7 dias de exposição as NOFs, tais como esteatose micro- e macro-vesicular, aumento dos MMC, exsudatos e focos hemorrágicos. A exposição aguda (3 e 7 dias) e a longo prazo (14 e 21 dias) de P. reticulata a NOFs induziu índices histopatológicos elevados associados a distúrbios circulatórios e respostas inflamatórias. Os resultados indicaram que os tecidos sanguíneo e hepático dos guppies são excelentes órgão alvo para estudar a ecotoxicidade das NOFs, confirmando que o P. reticulata é uma espécie biomonitora indicada para estudos sobre a ecotoxicidade das NOFs.

The processes and mechanisms that govern brain size evolution remain a widely discussed topic in evolutionary biology. How relative brain size relates to animal behaviour and cognition is even more controversial. Recent comparative and experimental studies have shown a positive relationship between relative brain size and complexity of behaviour. Some of the most important behaviours that have direct consequences for an individual’s fitness are reproductive behaviours, and they sometimes require quite complex behavioural repertoires. Selection for complex behaviour might therefore induce an expansion of brain size to allow for cognitively demanding tasks during courtship and mating. In the present study we investigated the effect of relative brain size on reproductive behaviour in male guppies (Poecilia reticulata), using fish from a recently established brain size artificial selection experiment. Females were paired with either a large- or a small-brained male, and we collected data on a suite of male courtship behaviours including sneak copulation attempts, courtship display, gonopodial swings and time spent following the female. Although the extent of orange colouration, a trait that varies across large- and small-brained males, affected male behaviour, we were not able to detect any difference in reproductive behaviour between the brain size selection lines. These results suggest that there is no strong association between male mating behaviour and relative brain size, and future studies will examine this question further. But currently, our results indicate that relative brain size might not be linked to reproductive behaviour to any significant extent, at least not in the guppy.

Made available in DSpace on 2016-08-10T10:39:23Z (GMT). No. of bitstreams: 1 Jefferson Mendes Gomide.pdf: 1020338 bytes, checksum: 0191262649084f3b90170c5b28b340dd (MD5) Previous issue date: 2008-12-17 / The invasion of new environments is related to the genetic variability of the species. The guppy (Poecilia reticulata) is a species introduced accidentally or artificially, arisen from different populations of captivity around the world. In some countries, these introductions are made repeatedly, particularly to control the growth of disease-transmitting mosquitoes in small lakes and streams in tropical countries. The Guppy is feeding the larvae of mosquitoes, preventing it from coming into adult life. Because of the need to obtain a better understanding of the differentiation of introduced populations, and this may reduce the impact of the introduction of exotic species, since it is the third leading cause of extinction of native species, three populations in different cities of the state of Goias were collected, and their metric features analyzed. The review sought to determine the rate of divergence among populations of free life, which contribute to the understanding of the process of colonization of natural environments by this alien species. The results indicated that the divergence between the populations analyzed, for most of the features is very large, ie the rate of divergence is greater than expected by neutral evolution, so that directional selection is expected to be acting on these characteristics. / A invasão de novos ambientes se relaciona com a variabilidade genética das espécies. O Guppy (Poecilia reticulata) é uma destas espécies introduzidas acidentalmente ou artificialmente, advindo de várias populações de cativeiro em todo o mundo. Em alguns países, estas introduções se deram várias vezes, particularmente para o controle do crescimento de mosquitos transmissores de doenças, em lagos e pequenos riachos nos países tropicais. O Guppy se alimenta das larvas desses mosquitos, impedindo que cheguem à fase adulta. Devido à necessidade de se obter uma maior compreensão da diferenciação de populações introduzidas, e com isto poder reduzir o impacto da introdução de espécies exóticas, já que é a terceira causa de extinção de espécies nativas, foram coletadas três populações em cidades diferentes do estado de Goiás, e as suas características métricas analisadas. A análise procurou determinar a taxa de divergência, entre populações de vida livre, que contribuirá para a compreensão do processo de colonização dos ambientes naturais por esta espécie exótica. Os resultados indicaram que a divergência entre as populações analisadas, para a maioria das características é muito grande, ou seja, a taxa de divergência é maior do que a esperada pela evolução neutra, de modo que seleção direcional deve estar atuando sobre estas características.

Cooperative behaviour among unrelated individuals is an evolutionary paradox. Research suggests that an individual’s propensity to cooperate and its response to experiencing cooperation or defection from its social environment consistently varies among individuals and as a function of external factors. The biological and psychological underpinnings of such behavioural variation remain unknown; they can, however, provide more insight into the evolution and maintenance of cooperation among non-kin. This thesis explores the proximate effects of experiences of cooperation or defection from the social environment, as well as possible proximate drivers of cooperative behaviour, using the Trinidadian guppy (Poecilia reticulata) as a study system. Firstly, the behavioural rules underpinning an individual’s decision to cooperate or not with unfamiliar individuals in the presence of specific or non-specific information were explored. When fish had information about their social partner’s cooperativeness, they behaved in a manner consistent with direct reciprocity, copying their partner’s last move. When paired with an ostensibly novel partner, a different, or at least additional, behavioural rule seemed to be employed. In order to help understand the drivers of individual variation in cooperative behaviour, phenotypic selection on cooperativeness was carried out over three filial generations, resulting in fish of high cooperativeness (HC) and low cooperativeness (LC). The divergence of individual cooperativeness observed between the two phenotypic selection lines suggests that cooperative behaviour in the context of predator inspection is at least in part heritable. Cooperative behaviour of F3 fish was found not to correlate with boldness or exploratory behaviour; HC and LC fish did, however, differ in some aspects of sociability and agonistic behaviour. Possible proximate neuromodulatory mechanisms underlying these differences in cooperativeness were also explored, focusing on brain expression patterns for the isotocin receptor (itr) gene in F3 females. HC females were found to have higher mid-section itr expression levels than LC females. Finally, I explored the effects of experiencing cooperation or defection on monoaminergic neurotransmission, which is thought to instantiate the effects of such experiences on the individual’s internal state. My findings suggest that experiencing cooperation or defection from the social environment affects internal state; this phenomenon may be crucial for the appropriate adjustment of the behavioural response to such experiences, and for the emergence of behavioural rules such as generalised reciprocity. Taken together these results suggest that neuromodulatory mechanisms are pivotal for the perception of stimuli from the social environment in the tested cooperative context and that variation in cooperative behaviour may be underpinned by individual differences in the structural properties of such systems. They also provide insight into how behavioural input may affect the behavioural response to such experiences, and ultimately how such mechanisms may lead to the evolution and maintenance of cooperation.

Synthetic progestins are steroid hormones, which are not only part of the hormonal contraceptives, but they are also used to treat a number of health problems in human. Due to the widespread use of progestin-based drugs, their residues are being found in wastewaters, from where they also enter into the wastewater treatment plants and surface waters. The aim of this thesis was to assess whether the synthetic progestin etonogestrel affects the secondary sexual characteristics and gonad histology of Endler´s guppy (Poecilia wingei). During the experiment, males and females were separately exposed to 3.2 and 320 ng.l-1 etonogestrel for 34 days. A group of fish reared in pure water (K) and group of fish reared in pure water containing the solvent dimethylsulfoxide (KS) served as controls. At the end of the test, all the fish were photographed to capture any color changes. Then the fish were sacrificed and fixed in 10 % buffered formalin solution for morphometric and histological analysis. Fish samples taken for morphometric analysis were photographed using QuickPHOTO MICRO 2.3 software and individual morphometric parameters were measured on the images taken. Fish sample processing for histological analysis included decalcification, dehydration, and pouring of the samples into paraffin blocks. Then paraffin blocks were cut with the thickness of about 4.5 um, resulting slides were stained with hematoxylin and eosin. Histological changes of the gonads were determined on the histological samples prepared in this way. In females exposed to both concentrations of etonogestrel occurrence of color spots was observed. Color spots are characteristic for male and in females indicate masculinization. In addition, females exposed to 320 ng.l-1 etonogestrel showed a change in anal fin morphometry to a gonopodium-like structure (modified anal fin of males serving as helping copulatory organ), a sign also suggesting masculinization. Furthermore, exposure of etonogestrel in both lower and higher concentration of etonogestrel reduced number of mature oocytes in the ovaries, and their occurrence decreased with increasing concentration. In males exposed to both concentrations of etonogestrel a smaller ratio of the length of 4th ray to the length of 6th ray of gonopodium was found. In addition, at concentration of etonogestrel 320 ng.l-1 a greater ratio of the length of 6th ray to body length and extension of length of 6th ray was observed. Although there were no changes, which would indicate hypermasculinization, these changes could have a negative impact on reproduction, or sexual selection by the female. Etonogestrel exposure had no effect on the normal development of testes, because predominantly mature spermatophores were found in males of all treatment groups. Based on these findings, we can say that etonogestrel, like other progestins, represents a real risk to fish if it occures in aquatic environment at concentrations reaching units of ng.l-1.

<p>Aromatase is the enzyme that catalysis the conversion of androgens into estrogens. It´s a member of P450 cytochrome family and is encoded by the CYP19-gene. The enzyme aromatase has an important role in regulating physiological and behavioral sexual mechanisms. This includes for instance activation, motivation and maintenance of the reproductive behaviors. The sexual behavior is affected by a complex series of events that requires the connection of endogenous hormonal and neurochemical changes with social interactions, especially between the opposite sexes. The aim of the present study was to examine how social interactions effect the aromatase expression and activity in the guppy brain. Guppy males were introduced into four different social conditions: Isolated, all male conditions, heterospecific (with zebrafish females) and conspecific female guppies. The focal males were kept under these conditions for two respectively four days. The sexual behavior, of each of the focal males was recorded daily during 10 minutes. The males with the guppy females showed, in contrast to the males in the other groups, a high frequency of reproductive behaviors. The brains of the focal males were collected and the brain aromatase activity was measured using tritiated water assay. I have also tried to analyze the gene-expression of aromatase with RT-PCR. However I was unable to analyze the results with the RT-PCR, because of possible primer-dimerization. Due to the limited time schedule, we were not able to solve the problem. ANOVA performed on the aromatase activity, revealed no significant difference between the different treatment groups. The variance was highest in the zebrafish category and lowest in the isolated males. There was no significant correlation between the mean number of reproductive behaviors and the aromatase activity in males that were together with guppy females. The results do not support the hypothesis that social interactions can affect the brain aromatase activity in guppy males.</p>