Made available in DSpace on 2014-07-29T15:16:32Z (GMT). No. of bitstreams: 1 Dissertacao mestrado Thiago Rocha.pdf: 3202693 bytes, checksum: 0519000d8f7c06ef3d8a404097ad8a82 (MD5) Previous issue date: 2012-02-29 / The mechanism of acute toxicity of the commercial formulation glyphosate, Roundup Transorb® (RDT), was investigated in the guppy (Poecilia reticulata) gills using proteomic technologies associated with analyses of histopathological indexes (HI´s), followed by quantification of histopathological lesions of the gills. Additionally, the present study describes a protocol for the analysis of fish behavior using measurements of the Index of morphofunctional behavior (Imb) and Total (Itb). The results indicate that the acute toxicity of RDT may change P. reticulata behavior as a consequence of changes in the expression of proteins associated with cyto-histopathological lesions of the gills. RDT LC50,96h for guppy females was 7.54 ± 0.93 μL.L-1, indicating that the species is moderately sensitive to this herbicide. Acute exposure to RDT sublethal concentration of 3.8 μL.L-1 induced time-dependent histopathological lesions of the gills in different epithelial and muscle cell types. HI´s were related to increase in severity and frequency of histopathological lesions and suggest that RDT may cause regressive, circulatory, and progressive disorders in the guppy gills. Two-dimensional electrophoresis associated with mass spectrometry and biocomputing permitted to verify 48 spots of proteins/isoforms regulated by RDT, which are involved in different cell processes, such as energy metabolism, regulation and maintenance of cytoskeleton, metabolism of nucleic acids and proteins in response to stress. The study of behavior biomarkers (BM´s) indicates that Imb and Itb were viable in the analysis of P. reticulata behavioral changes induced by RDT. Furthermore, proteomic and histological changes in the gills of P. reticulata induced by RDT may be histopathological and proteomic BM´s to biomonitor water pollution caused by glyphosate-based herbicides. / O mecanismo de toxicidade aguda da formulação comercial de glifosato, Roundup Transorb® (RDT), foi investigado para as brânquias do guaru (Poecilia reticulata) por meio de tecnologias proteômicas associadas às análises dos índices histopatológicos (HI´s), seguido da quantificação das lesões histopatológicas branquiais. Além disso, o presente trabalho também descreve um protocolo para análise do comportamento de peixes utilizando mensurações dos Índices de Comportamento Morfofuncional (Icmf) e Total (Ict). Os resultados indicam que a toxicidade aguda do RDT pode alterar o comportamento de P. reticulata como reflexo das mudanças de expressão das proteínas associadas às lesões cito-histopatológicas branquiais. A CL50,96h do RDT para as fêmeas do guaru foi de 7,54 ± 0,93 μL.L-1, a qual indica que esta espécie é moderadamente sensível a esse herbicida. A exposição aguda à concentração subletal de 3,8 μL.L-1 de RDT induziu lesões histopatológicas branquiais de modo tempo dependente em diferentes tipos celulares epiteliais e muscular. Os HI´s foram relacionados com o aumento da severidade e da frequência das lesões histopatológicas e apontam que o RDT pode causar distúrbios regressivos, circulatórios e progressivos nas brânquias do guaru. A eletroforese bidimensional associada à espectrometria de massa e bioinformática permitiu verificar 48 spots de proteínas/isoformas reguladas pelo RDT, as quais estão envolvidas em distintos processos celulares, tais como metabolismo energético, regulação e manutenção do citoesqueleto, metabolismo de ácidos nucléicos e proteínas de resposta ao estresse. O estudo dos biomarcadores (BM´s) comportamentais indica que o Icmf e o Ict foram viáveis na análise das alterações comportamentais de P. reticulata induzidas pelo RDT. Ademais, as modificações proteômicas e histológicas nas brânquias de P. reticulata induzidas pelo RDT podem ser BM´s histopatológicos e proteômicos no biomonitoramento da poluição aquática por herbicidas baseados em glifosato.

Submitted by Cláudia Bueno (claudiamoura18@gmail.com) on 2016-02-11T12:23:04Z No. of bitstreams: 2 Dissertação - Michelle Furquim Leão - 2007.pdf: 19618077 bytes, checksum: 185360e935aab77ea3553e7a7d1c4093 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-02-12T10:57:42Z (GMT) No. of bitstreams: 2 Dissertação - Michelle Furquim Leão - 2007.pdf: 19618077 bytes, checksum: 185360e935aab77ea3553e7a7d1c4093 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-02-12T10:57:42Z (GMT). No. of bitstreams: 2 Dissertação - Michelle Furquim Leão - 2007.pdf: 19618077 bytes, checksum: 185360e935aab77ea3553e7a7d1c4093 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2007-08-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The sharp toxicity of the herbicide original Roundup (Glifosato), one of the more acquaintances and maybe one of the more used dessecantes in direct planting in the farmings in the area Centro Oeste and in every country now, it was investigated through the effects detected in the fish Poecilia viviparous... / A toxicidade aguda do herbicida Roundup original (Glifosato), um dos mais conhecidos e talvez um dos mais utilizados dessecantes em plantio direto nas lavouras na região Centro Oeste e em todo país atualmente, foi investigada através dos efeitos detectados no peixe Poecilia vivípara...

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.

Herbivory is thought to be nutritionally inefficient relative to carnivory and omnivory. But, herbivory evolved from carnivory in many lineages, suggesting that there are advantages to eating plants. To understand the adaptive significance of the transition from carnivory to herbivory, I proposed five hypotheses for the adaptive evolution of herbivory and reviewed the current freshwater literature to identify conditions where eating plants might be adaptive over eating animals. I tested three of these ideas (Suboptimal Habitat, Heterotroph Facilitation, and Lipid Allocation) using the herbivorous Sailfin Molly (Poecilia latipinna)and identified each as a potential mechanism for the evolution of herbivory. To understand the origins of herbivory in Sailfin Mollies, I reconstructed ancestral habitats and dietsacross a phylogeny of the genus Poeciliaand then used phylogenetically independent contrasts to identify patterns of diet evolution. I found that the degree of herbivory increases with increasing salinity affiliation, suggesting that in this genus, herbivory evolved as an adaptation for invading less productive saline habitats from freshwaters. This result is consistent with the Suboptimal Habitat hypothesis, which states that herbivory allows organisms to invade and persist in ‘suboptimal’ habitats. To understand how herbivory is maintained in extant populations, I raised juvenile Sailfin Mollies in mesocosms and enclosure cages placed in the Everglades to document that dietary autotrophic lipids play a role in early life history by supporting rapid growth (Lipid Allocation). However, dietary bacterial fatty acids promoted fish survival, consistent with the Heterotroph Facilitation hypothesis, which states that indirect detritivory supplements the herbivorous diet. Finally, I quantified periphyton quality/availability and consumer density across the Everglades landscape to examine the correlates of trophic dynamics in nature. Results revealed that herbivores can persist in diverse habitats and survive on varying resources when habitats are unfavorable, supporting the Suboptimal Habitat hypothesis.

No description available.

Background: Multidirectional interactions in social networks can have a profound effect on mate choice behavior; e.g., Poecilia mexicana males show weaker expression of mating preferences when being observed by a rival. This may be an adaptation to reduce sperm competition risk, which arises because commonly preferred female phenotypes will receive attention also from surrounding males, and/or because other males can copy the focal male's mate choice. Do P. mexicana males indeed respond to perceived sperm competition risk? We gave males a choice between two females and repeated the tests under one of the following conditions: (1) an empty transparent cylinder was presented (control); (2) another ("audience") male inside the cylinder observed the focal male throughout the 2nd part, or (3) the audience male was presented only before the tests, but could not eavesdrop during the actual choice tests (non-specific sperm competition risk treatments); (4) the focal male could see a rival male interact sexually with the previously preferred, or (5) with the non-preferred female before the 2nd part of the tests (specific sperm competition risk treatments). Results: The strength of individual male preferences declined slightly also during the control treatment (1). However, this decrease was more than two-fold stronger in audience treatment (2), i.e., with non-specific sperm competition risk including the possibility for visual eavesdropping by the audience male. No audience effect was found in treatments (3) and (5), but a weak effect was also observed when the focal male had seen the previously preferred female sexually interact with a rival male (treatment 4; specific sperm competition risk). Conclusion: When comparing the two 'non-specific sperm competition risk' treatments, a very strong effect was found only when the audience male could actually observe the focal male during mate choice [treatment (2)]. This suggests that focal males indeed attempt to conceal their mating preferences so as to prevent surrounding males from copying their mate choice. When there is no potential for eavesdropping [treatment (3)], non-specific specific sperm competition risk seems to play a minor or no role. Our results also show that P. mexicana males tend to share their mating effort more equally among females when the resource value of their previously preferred mate decreases after mating with a rival male (perceived specific sperm competition risk), but this effect is comparatively weak.

Male mating signals convey important mate-quality information to females and are regulated by androgens. Endocrine disrupting compounds (EDCs) are chemicals that interfere with proper hormonal functioning in exposed animals, causing altered hormone levels and resulting in changed reproductive characteristics, including mating signals. Altered signals can have ecological implications by influencing population and community dynamics and evolutionary implications via trans-generational reduction in signal reliability leading to reduced preference and eventual loss of the signal trait. I examined the effects of exposure to environmentally relevant concentrations of atrazine, a widely used herbicide and EDC, on mating signals and behaviors in male guppies, a sexually dimorphic freshwater fish. Guppies were exposed either during adulthood or embryonic development. Prolonged atrazine exposure during adulthood reduced the size of the carotenoid-based ornament, the number of courtship displays performed, and aggression towards competing males. Embryonic exposure did not affect survival to adulthood and the time to develop male-specific morphologies. But there was a trend for smaller genitalia, and the ornament size was significantly increased. Possible increases in immunocompetence as a result of slight estrogenecity may have allowed for greater carotenoid allocation to the ornament. Embryonic exposure also resulted in reduced courtship behavior, forced copulatory attempts and aggression towards competitors; female guppies found these males less attractive. The low dose had the strongest effects with embryonic exposure, indicating the importance of low-dose exposures. These studies highlight the effects of low and environmentally relevant doses of atrazine on mating signals and behaviors in exposed wildlife. A mathematical model was used to understand the evolutionary effects of EDCs on the optimal allocation of carotenoids between ornament and immunocompetence. Animals obtain carotenoids through their diet, and allocate some of this to enhance immune function and the rest to ornaments for mate attraction. The model replicates the disruption of carotenoid-based ornaments as a result of EDC-exposure, and predicts that signal reliability will be reduced. The model simulates an evolutionary shift in the optimal allocation if exposure spanned multiple generations, but signal reliability is not restored. Including additional selective forces like predation further suppresses signal reliability.

This thesis demonstrates how the intermittent nature of seasonal tropical fresh waters facilitates and impedes the dispersal of fish and how the variability among residual dry season pools affects the dynamics of isolated populations. I focused on the seasonal ecology of Poecilia gillii from pools in a steep gradient, intermittent stream in Costa Rica. Water temperature and dissolved oxygen concentration were affected by season, by between-pool differences, and by the interaction between seasonal and spatial influences. Seasonal flooding resulted in a catastrophic loss of fish from most pools. Population loss was influenced by the susceptibility of the pools to flooding and population density, with mortality occurring primarily in nearby desiccating "graveyard" pools. Pools increased in population size and density over the 5-month post-flood study period, and their densities converged to their pre-flood values. Variability in the rate of increase among pools was related to water quality and population density. Striking changes in the size and abundance of males over the season suggest social influences on maturation in Poecilia gillii.

Lithium is widely used in the management of bipolar disorder, yet memory impairment is a serious side effect. To assess the effects of lithium on spatial working and reference memories, we have employed a plus maze utilizing spontaneous alternation (SA) and place-learning paradigms in two experiments with the black molly fish. Four treatment groups were gavaged with 20 μl of a 10, 100, or 1000 mM lithium chloride (LiCl) solution or ddH2O vehicle every 12 h for 22 to 24 days. On Day 15, subjects began an 8-day SA task or a 10-day place-learning task. Results indicate that there is a significant difference in SA performance among the treatment groups for Days 1, 2, and 3. Results of the place-learning task indicate that the 1 M dose group needed significantly more trials to reach criterion and made significantly fewer correct first choices than the other dose groups. Capillary ion analysis determinations of plasma and brain lithium levels illustrate linear dose-response relationships to doses administered. Regression analyses indicate that there is a relationship between SA performance and plasma/brain lithium levels during the initial part of testing. Collectively, the results indicate that chronic lithium administration impairs spatial working and reference memories.

Several species‐specific proteins have been identified by polyacrylamide gel electrophoresis (PAGE) of skeletal muscle extracts from the diploid gynogen, Poecilia formosa, its related triploid unisexuals, and their sympatric, bisexual species, P. mexicana and P. latipinna. These water‐soluble, low molecular weight proteins (7,000‐13,000) comigrate with a fraction of purified rabbit parvalbumin on nondenaturing gels and show staining properties similar to rabbit parvalbumins. The electrophoretic patterns of these muscle proteins provide a set of distinctive phenotypic markers for each of the host species involved in naturally occurring breeding complexes with P. mexicana × P. latipinna show no evidence of sexual dimorphisms. Furthermore, the hybrid phenotypes are those that would be predicted from appropriate combinations of parental alleles at three gene loci. The patterns found by PAGE for several generations of pedigreed stocks of P. formosa show strictly matroclinous inheritance of a characteristic muscle protein phenotype and coupled with the electrophoretic patterns of several enzymic proteins reflect the probable hybrid origin of this diploid unisexual. Finally, paternal contributions by P. mexicana to the hybrid genome of triploid unisexuals are clearly demonstrated by comparative analyses of muscle protein phenotypes for P. formosa and its contemporary host species. Our identification of distinctive phenotypic markers in the muscle proteins of several poeciliid species involved in unisexual‐bisexual breeding complexes provides an important new tool for further studies on the adaptive significance of unisexuality, hybridization, and fixed heterozygosity in the evolutionary biology of these fishes.