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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Promene trofičkih karakteristika obične krastače Bufo bufo, Mertens and Müller, 1928 (Bufonidae: Anura) tokom postmetamorfoze / Changes in trophic characteristics of common toad Bufo bufo, Mertens and Müller, 1928 (Bufonidae: Anura) during postmetamorphosis

Čađenović Natalija 10 October 2014 (has links)
<p>Analiza ishrane je urađena na uzorcima 16 populacija vrste <em>Bufo bufo</em>, sa&nbsp;ukupno 356 adultnih jedinki. Od toga 8 uzoraka pripada podvrsti<em> B.b. bufo</em>-populacija sa 158, a 8 uzoraka <em>B.b spinosus</em> populacija sa 198 jedinki. Za analizu&nbsp;ishrane je kori&scaron;ćen i uzorak od 150 primjeraka, tek metamorfoziranih jedinki.&nbsp;Uzorci populacija su prikupljeni sa teritorije Srbije i Crne Gore. Ishranu ispitivanih&nbsp;podvrsta roda <em>Bufo</em>, na svim lokalitetima čine jedinke plijena isključivo predstavnici&nbsp;Invertebrata. Kod obje podvrste dominantan plijen su pripadnici reda Coleoptera i&nbsp;Hymenoptera kod <em>B.b. spinosus&nbsp;</em>(70,05%,16,92%), &nbsp;kod <em>B.b. bufo&nbsp;</em>(59,69%, 22,61%).&nbsp;Multivarijantna analiza urađena na ukupnom uzorku pokazujeda postoji statistički&nbsp;značajna zavisnost ispitivanih morfolo&scaron;kih karaktera žaba i promjenljive&nbsp;morfologije plijena. Korespodentna analiza je pokazala da jedinke obje &nbsp;podvrste&nbsp;preferiraju sličan plijen samo &scaron;to je učestalost tog plijena različita po podvrstama i&nbsp;polovima. Kod tek metamorfoziranih jedinki Anura na oba lokaliteta prisutan je isti&nbsp;plijen sa malim procentualnim razlikama. Prisustvo relativno visokog procenta&nbsp;Chironomidae ukazuje da ove jedinke nisu u potpunosti pre&scaron;le na terestrični način&nbsp;života. Dok prisustvo visokog procenta familija Formicidae i Byrrhidae ukazuje na&nbsp;<br />ishranu kojoj inače teže pripadnici vrste <em>B. bufo</em>, prelaskom na terestrični način&nbsp;života. Vrijednosti &scaron;irina trofičkih ni&scaron;a (B<sub>A</sub>) po podvrstama pokazuju da je podvrsta <em>B.b. spinosus</em><i>&nbsp;</i>(B<sub>1</sub>A=0,15) imala neznatno manju vrijednost u odnosu na podvrstu&nbsp;<em>B.b. bufo</em> (B<sub>1</sub>A=0,16) , &scaron;to ukazuje na to da su pripadnici obje podvrste imale&nbsp;prilično ujednačenu ishranu. Na osnovu taksonomije plijena zabilježeno je veoma&nbsp;visoko preklapanje ni&scaron;a ishrane između podvrsta (95%). Veoma su oskudni&nbsp;literaturni podaci o ishrani ove dvije podvrste, &scaron;to podatke i rezultate ovog rada čini&nbsp;posebno vrijednim.</p> / <p>Diet analysis was conducted on the samples of 16 populations of species&nbsp;<em>Bufo bufo</em>, &nbsp;with total of 356 adult individuals. Among that, 8 samples belonged to&nbsp;sub-species <em>B.b. bufo</em> &ndash; population with 158 samples, and another 8 samples&nbsp;belonged to <em>B.b. spinosus</em>, with population of 198 individuals. For diet analysis we&nbsp;also used the sample of 150 individuals which have just finished metamorphosis.&nbsp;Population samples were collected from the territories of Serbia and Montenegro.&nbsp;The diet of investigated subspecies belonging to the genus <em>Bufo</em> from all localities,&nbsp;was composed of the Invertebrata exclusively. Coleoptera and Hymenoptera were dominant prey items in both groups <em>B.b. spinosus&nbsp;</em>(70.05%, 16.92%), and <em>B.b. bufo&nbsp;</em>(59.69%, 22.61%). Multivariate statistical analysis which was performed on the&nbsp;entire sample, showed existence of statistically significant dependence of&nbsp;morphological traits of common toadand variable morphology of prey. &nbsp;Correspondent analysis showed that individuals of both subspecies prefer similar&nbsp;prey, but the frequency of the prey occurance at different subspecies and sexes is&nbsp;different. Recently metamorphosed Anuran individuals from both localities, take&nbsp;the same prey with a small differences inpercentage. The presence of a relatively&nbsp;high percentage of Chironomidae indicates that these individuals are not completely&nbsp;moved on to terrestrial life. While the presence of a high percentage of the families&nbsp;Formicidae and Byrrhidae indicates a diet which usually species <em>B. bufo </em>aspire&nbsp;during the transition to terrestrial life. Values (B<sub>A</sub>) of trophic niche width (B<sub>A</sub>)&nbsp;indicate that the subspecies <em>B.b. spinosus&nbsp;</em>(B<sub>A</sub> =15) had a slightly lower value&nbsp;compared to subspecies <em>B.b. bufo</em> (B<sub>A</sub> =15) which indicates that both subspecies had&nbsp;a fairly uniform diet. Based on the taxonomy of prey, very high dietary &nbsp;niche&nbsp;overlap between subspecies was recorded (95%). Since there are very scarce&nbsp;<br />literature data about diet of the two subspecies, the data and results of this thesis are&nbsp;<br />particularly valuable.&nbsp;</p>
2

Diversidade de vespas sociais (Hymenoptera: Vespidae) e utilização de recursos florais em uma área de caatinga na Bahia

Melo, André Carneiro 09 February 2007 (has links)
Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-10-31T13:07:49Z No. of bitstreams: 1 andrecarneiromelo.pdf: 1141678 bytes, checksum: c1d480fce80e0298d42b456806dd9e19 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-12-15T13:00:03Z (GMT) No. of bitstreams: 1 andrecarneiromelo.pdf: 1141678 bytes, checksum: c1d480fce80e0298d42b456806dd9e19 (MD5) / Made available in DSpace on 2016-12-15T13:00:03Z (GMT). No. of bitstreams: 1 andrecarneiromelo.pdf: 1141678 bytes, checksum: c1d480fce80e0298d42b456806dd9e19 (MD5) Previous issue date: 2007-02-09 / A entomofauna de visitantes florais da caatinga, de modo geral, tem sido pouco estudada, e entre os grupos de insetos mais importantes no estudo de comunidade estão os Hymenoptera, em particular as vespas sociais. Embora os estudos de insetos visitantes de flores focalizem uma ou poucas espécies, uma perspectiva de comunidade é importante para apontar caminhos para entender a partição e competição por recursos e seus efeitos sobre a estrutura da comunidade. Em função disso, este trabalho visou caracterizar a estrutura da comunidade de vespas sociais visitantes de flores da caatinga, identificando as espécies vegetais e o modo de utilização desses recursos. O trabalho de campo foi conduzido de Outubro de 2005 a Setembro de 2006, sendo realizadas coletas mensais constituídas de dois dias de atividades, totalizando-se 10 horas de trabalho/dia. Em cada dia de amostragem, dois coletores percorriam uma trilha pré-existente ao longo da qual eram vistoriadas as plantas floridas, onde foram coletadas as espécies de vespas sociais que visitavam as inflorescências, com auxílio de rede entomológica. A comunidade de vespas sociais foi caracterizada por meio de diferentes índices: freqüência relativa, constância e diversidade (H’) e os padrões de uso dos recursos florais por esses insetos foram investigados através da comparação da amplitude dos nichos tróficos. Foram registrados 172 indivíduos de vespas sociais, distribuídos em oito espécies. A abundância mensal do número de indivíduos de vespas apresentou uma variação significativa (χ2= 169,16; p<0,0001) e a diversidade obtida no presente estudo foi de H’=0,66, este valor de diversidade foi menor que os obtidos em outros trabalhos com vespas em diferentes localidades. Essa diferença se deve ao fato do bioma caatinga está sujeito a uma ampla variação sazonal. As vespas visitaram flores de 26 espécies vegetais, destas, 11 (42%) foram visitadas por apenas um ou dois indivíduos e 16 (61%) foram visitadas por apenas uma ou duas espécies. A vespa Polybia ignobilis (Haliday, 1836) visitou 21 espécies vegetais, apresentando o nicho trófico mais amplo (4,64). Já as espécies Mischocyttarus cearensis Richards, 1945 e Brachygastra lecheguana (Latreille, 1824), apresentaram os nichos mais estreitos (0,76 e 0,67, respectivamente). A variação nos valores de amplitude de nicho para as espécies de vespas pode estar relacionada a alguns fatores que influenciam a atividade forrageadora, como diferenças da biomassa de algumas espécies, que revela a capacidade de forrageio destes insetos e o tamanho da população, que aliado à necessidade de suprimento energético da colônia, determina o nível de consumo dos recursos, o que interfere na amplitude de forrageio dessas espécies. A plasticidade dessas espécies em utilizar inúmeras fontes florais revela a importância destes insetos na coleta de néctar de diferentes espécies vegetais da caatinga, demonstrando a necessidade de estudos mais acurados que visem avaliar a eficiência das vespas sociais no processo de polinização das plantas. / The insect fauna of the caatinga floral visitors in general, has been little studied, and among the most important groups of insects in the study community are the Hymenoptera, in particular social wasps. Although studies of insect visitors to flowers focus on one or a few species, a perspective of community is important to point out ways to understand the partition and competition for resources and their effects on community structure. As a result, this study aimed to characterize the community structure of social wasps visitors to flowers of the savanna, identifying plant species and mode of use of those resources. Fieldwork was conducted from October 2005 to September 2006, and collected monthly consist of two days of activities, totaling up to 10 hours of work / day. On each sampling day, two collectors traveled a pre-existing track along which were inspected flowering plants, which were collected species of social wasps visiting the inflorescences with entomological net. The community of social wasps was characterized by means of different indices: relative frequency, consistency and diversity (H ') and the patterns of use of floral resources by these insects were investigated by comparing the amplitude of trophic niches. We recorded 172 individuals of social wasps, distributed in eight species. The abundance of the monthly number of individuals of wasps showed a significant variation (χ 2 = 169.16, p <0.0001) and diversity obtained in the present study was to H '= 0.66, this value was smaller than the range obtained in other studies with wasps in different localities. This difference is due to the savanna biome is subject to wide seasonal variation. The wasps visiting flowers of 26 species of these, 11 (42%) were visited by one or two subjects and 16 (61%) were visited by only one or two species. The wasp Polybia ignobilis (Haliday, 1836) visited 21 plant species, with the broader trophic niche (4,64). Already species Mischocyttarus cearensis Richards, 1945 and Brachygastra lecheguana (Latreille, 1824), showed narrower niches (0.76 and 0.67, respectively). The variation in the values of niche breadth for species of wasps can be related to some factors that influence the foraging activity, such as differences in biomass of some species, which shows the ability of these insects foraging and population size, which together with the need energy supply of the colony, determines the level of resource consumption, which interferes with foraging range of these species. The plasticity of these species using numerous floral sources reveals the importance of these insects in the collection of nectar from different plant species of the caatinga, demonstrating the need for more accurate studies aimed at evaluating the effectiveness of social wasps in pollination of plants.
3

A importância da Araucaria angustifolia na dieta de pequenos roedores silvestres em área de floresta com araucária no sul do Brasil

Perini, Adriana Albuquerque 24 February 2010 (has links)
Made available in DSpace on 2015-03-05T16:20:42Z (GMT). No. of bitstreams: 0 Previous issue date: 24 / Bolsa para curso e programa de Pós Graduação / Pequenos roedores formam um importante elemento faunístico na Floresta com Araucária. Em geral, considera-se que há uma forte relação entre a produção de sementes (pinhões) pela Araucaria angustifolia e a abundância desses animais. Isso devido ao alto conteúdo energético dos pinhões e alta produção dessas sementes, concentrada principalmente nos meses de inverno, quando há um decréscimo na disponibilidade de outros recursos tróficos. No presente estudo, avaliei a importância da A. angustifolia na dieta de pequenos roedores silvestres em área de Floresta com Araucária (Estação Ecológica de Aracuri-Esmeralda, no município de Muitos Capões, RS, Brasil). Realizei sete séries mensais ou bimestrais de captura de pequenos roedores (sete noites de captura por série), de outubro/2008 a julho/2009, representando períodos sem (out/08 a fev/09) e com (abr a jul/09) o recurso pinhão disponível na floresta. Utilizei 30 armadilhas do tipo “pitfall” (baldes de 62 litros) e 50 armadilhas tipo ratoeira (“snap trap”). Capt / Small rodents comprise an important faunal component of the Brazilian Araucaria Forests. It is suggested that there is a strong relation between seed production of the araucaria „pine&#8223; Araucaria angustifolia and small-rodent abundance. Such relation would be due to the high energetic content of this conifer&#8223;s seeds (known as „pinhões&#8223;) and also high seed production. Such production is concentrated during autumn and winter months, when there is reduction in overall resource availability. In the present study I evaluated the importance of A. angustifolia in the diet of wild small rodents in an area of Araucaria Forest in southern Brazil (Ecological Station of Aracuri-Esmeralda, Muitos Capões, RS, Brazil). I conducted seven capture sessions (seven nights each) monthly of bi-monthly from October/2008 to July/2009, representing a period out of A. angustifolia seed production (October to February) and during seed production (April to July). I used 30 pitfall traps (62 l) and 50 snap traps. Dur
4

Effect of submerged macrophytes on the structure of lake ecosystem and trophic relationships among fishes

VEJŘÍKOVÁ, Ivana January 2019 (has links)
This Ph.D. Thesis is focused on the effect of submerged vegetation on the structure of lake ecosystem and trophic relationships among fishes. Succession of submerged vegetation is a dynamic process and the vegetation community may change dramatically even during a year. Many environmental factors have impact on the succession of submerged vegetation and consequently the presence of the vegetation has substantial impact on the aquatic ecosystem. Nutrient level (mainly nitrogen and phosphorus) plays a key role in the succession of freshwater ecosystems. Further, herbivory significantly influences species composition and biomass of macrophytes and macroalgae. Herbivory of fish is a foraging strategy that is dependent on temperature. Foraging preferences of fish may suppress the palatable species. The rate of herbivory affects plant growth patterns and thus inpalatable species may be advantaged in the competition among plants. In aquatic ecosystems, herbivory is often performed by omnivorous species. The diet preferences of omnivorous fish differ among aquatic ecosystems and submerged vegetation can shape their trophic niches substantially.
5

Ecologia trÃfica de quatro espÃcies de peixes de um rio no semiÃrido, Pentecoste - Cearà / Trophic ecology four species of fish a river in the semiarid, Pentecost - Ceara

Ubirajara Lima Fernandes 21 June 2011 (has links)
A maioria dos rios do semiÃrido apresentam regimes irregulares e intermitentes, com um sà perÃodo anual de escoamento na chegada das precipitaÃÃes pluviomÃtricas que caracterizam o perÃodo chuvoso. Nesses rios, as perturbaÃÃes hidrolÃgicas naturais exercem forte influÃncia na organizaÃÃo do sistema, sendo as interaÃÃes alimentares complexas e modificadas pela sazonalidade e pela produtividade do sistema. A dieta de peixes pode variar de acordo com a disponibilidade de recursos alimentares de origem autÃctone ou alÃctone, bem como em resposta à variaÃÃo sazonal. A hipÃtese do presente estudo à de que em um rio do semiÃrido as espÃcies de peixes herbÃvoras/ onÃvoras apresentam partilha de recursos trÃficos. O objetivo foi determinar a partilha de recursos trÃficos a partir da dieta de quatro espÃcies de peixes no rio Curu. As coletas foram realizadas em um trecho do rio Curu (Pentecoste, CearÃ), no perÃodo chuvoso de 2010. Foi analisado o conteÃdo estomacal de 197 indivÃduos das seguintes espÃcies: Astyanax bimaculatus (27), Astyanax fasciatus (79), Poecilia vivipara (90) e Hypostomus jaguribensis (1), pelo mÃtodo volumÃtrico e frequÃncia de ocorrÃncia, para o cÃlculo do Ãndice alimentar (IAi). Com os dados morfomÃtricos foi obtido o Quociente Intestinal (QI). A amplitude de nicho foi estimada atravÃs do Ãndice de Levins e a sobreposiÃÃo trÃfica atravÃs do Ãndice de Pianka. PadrÃes de sobreposiÃÃo de nicho trÃfico foram calculados e estatisticamente testados contra um modelo nulo, atravÃs dos algoritmos de randomizaÃÃo RA3 e RA4. A dieta de A. bimaculatus foi constituÃda por 13 itens, e a de A. fasciatus constituÃda por 15, com preferÃncia alimentar pela alga filamentosa Spirogyra em ambas as espÃcies, sendo a importÃncia alimentar de 89,34% para A. bimaculatus e 96,86% A. fasciatus. A dieta de P. vivipara foi constituÃda por 60 itens, com maior importÃncia para as algas diatomÃceas (28,82%), clorofÃceas (23,17%) e cianofÃceas (5,2%), tendo as clorofÃceas Spirogyra e Closterium, maior importÃncia alimentar com 12,89% e 8,85%, respectivamente e fragmentos de insetos aquÃticos com 39,18%. A dieta de H. jaguribensis esteve constituÃda por 42 itens alimentares, com maior importÃncia para Spirogyra com 23,42%, e Compsopogon com 19%. O grupo diatomÃcea apresentou maior nÃmero de itens na dieta com 21 tÃxons e 16,38% de IAi, seguido pelo item alimentar detrito com 27,72% de importÃncia. De acordo com o quociente intestinal A. bimaculatus e A. fasciatus apresentam intestino caracterÃstico de carnÃvoro/onÃvoro e P. vivipara de herbÃvoro. A anÃlise de variÃncia (ANOVA) para os valores mÃdios do quociente intestinal dos peixes analisados foi significativa com F= 3,50, df = 2, p< 0,05. A largura de nicho foi maior em P. vivipara com 1.32, seguido por A. bimaculatus com 0,78 e A. fasciatus com 0,426. Maior sobreposiÃÃo de nicho ocorreu entre as espÃcies de Astyanax com o valor de 0,98. A anÃlise dos modelos nulos realizados pelos itens totais e os itens agrupados indicou que os valores observados foram sempre maiores do que os esperados para a matriz RA3 e RA4. A variÃncia mÃdia observada tambÃm foi maior do que a simulada. De acordo com a dieta das quatro espÃcies analisadas, destacam a importÃncia de itens de origem autÃctone, principalmente as algas. Os modelos nulos indicam que as espÃcies de peixes herbÃvoras/onÃvoras apresentam partilha de recursos trÃficos, ou seja, a competiÃÃo nÃo à o agente estruturador dessa comunidade. / The semiarid rivers present two patterns: the intermittent and the irregular one, with a single flowing off period per year, during the rainy season. In these rivers, the natural hydrological disturb acts as an important factor driving the organization of the system, in which feeding interactions are complex and modified by seasonality and system productiveness. Fishes often feed on autochthonous or allochthonous resources, with their diets varying according to the with seasonal variation of food availability. The hypothesis of this the present study is that in the semiarid river herbivorous/onivorous fish species present trophic resources partitioning. The major aim of this study the present investigation is was to determine the trophic resources partitioning for four species of fishes at in the Curu River. Field work collections were carried out throughout the rainy season, at the Curu River, in Pentecoste city town, in Cearà state. The stomach content of 197 individuals of the species Astyanax bimaculatus (27), Astyanax fasciatus (79), Poecilia vivipara (90) e Hypostomus jaguribensis (1) was analyzed through the volumetric method in order to obtain for the frequency of each feeding item, so that the Index of Alimentary Importance (IAi) could have been measured. The morphometric data were used to obtain the intestinal quotient (IQ), the niche breadth estimated for the Levinsâ index and the trophic overlap for the Piankaâs index. Patterns of trophic niche overlap were calculated and statistically tested against a null model using the randomization algorithms RA3 and RA4. A. bimaculatus and A. fasciatus fed on 13 and 15 items, respectively. Both species presented feeding preferences for the filamentous algae Spirogyra sp., encompassing 89.34% and 96.86% of their diets, respectively. Poecilia viviparaâs diet comprised 60 items, mainly made up of algae (Bacillariophyta - 28.82%, Chlorophyta - 23.17% and Cyanophyta â 5.2%). Amongst the âgreen algaeâ, Spirogyra sp. (12.89%) and the Closterium sp. (8.85%) were the chief principal items eaten. Aquatic insects (39.18%) made up the second most important item. A total of 42 items compounded the diet of H. jaguribensis, which detritus (27,72%), the algae Spyrogira sp. (23.42%) and Compsopogon sp. (19%) were the foremost most important items. The diatom group comprised the most abundant item, with 21 taxa and 16.38% of IAi. According to the intestinal quotient, A. bimaculatus e A. fasciatus showed a typical carnivorous/omnivorous intestine, whereas P. vivipara showed a herbivorous one. The analysis of variance shows that the intestinal quotient varied among species (F = 3.50; d.f = 2; p < 0.05). The niche breadth was greater for P. vivipara (1.32), followed by A. bimaculatus (0.78) and A. fasciatus (0.426). The higher niche overlap occurred within the Astyanax species (0.98). The null model analysis carried out for the total and clustered grouped items indicated that the observed values were always higher than the expected ones for the RA3 and RA4 matrices. In addition, the mean observed variance was higher than the simulated one. The four studied fish species fed mainly on autochthonous items, chiefly on algae. The null models demonstrated that there is a resource partitioning amongst these herbivorous/omnivorous fish species, where competition seems not to be the structuring agent.
6

A Lake Divided: Regional Shifts in Trophic Niche Structure of Lake Powell Fishes Corresponding to the Invasion of Quagga Mussels

St Andre, Nathan Richard 01 December 2020 (has links)
Introduced species can become invasive and cause catastrophic alterations to the system they invade. Both zebra mussels (Dreissena polymorpha) and quagga mussels (Dreissena bugensis) have caused significant ecosystem alterations wherever they have invaded. These Dreissena species have caused changes in water quality and biodiversity and have disrupted energy pathways which can have cascading effects on other trophic levels. Recently quagga mussels invaded Lake Powell, a reservoir located in the southwestern USA, creating the possibility of a trophic cascade that could alter energy flow in the reservoir and change the trophic niche structure of the fishes in the lake. However, due to Lake Powell’s large size, dynamic nature, and complex hydrological structure, the effects of quagga mussels on fish species is uncertain. To determine impacts of quagga mussels on Lake Powell fishes, we quantified trophic niches of five species of sport fish over three years (2017-2019) using stable isotopes of nitrogen, δ15N, and carbon, δ13C. We test the following hypothesis: quagga mussels will cause a shift in trophic niche in more pelagic fishes such that pelagic fishes decrease in trophic position and shift toward use of more littoral energy. In addition, we compare the trophic niche of these species with a previous study on the trophic niche of fish in Lake Powell prior to full colonization of the lake by quagga mussels (2014-2015). In general, fish in the southern region of the lake exhibited a trend of decreasing δ15N suggesting decreasing trophic position and an enrichment of δ13C indicating a littoral energy shift in some species. Fish in the northern region of the lake exhibited a slight increase in trophic position and a shift towards pelagic energy across the same time period. These shifts support the hypothesis with pelagic fish experiencing a trophic niche shift, in the direction predicted, but only in the southern region of Lake Powell. Additionally, this shift is not exclusive to pelagic fish, but happened in all five species. Sediment laden input from the Colorado River may offset the impact of quagga mussels in the northern region of the lake resulting in observed regional differences.
7

Changes in trophic structure of decomposer communities with land use in Central European temperate forests

Klarner, Bernhard 20 January 2014 (has links)
No description available.
8

Colour polymorphism and its function in Hippolyte obliquimanus: camouflage and resource use diversification / Polimorfismo de cor e sua função em Hippolyte obliquimanus: camuflagem e diversificação no uso de recursos

Rafael Campos Duarte 10 April 2017 (has links)
This thesis addresses the mechanisms regulating the evolution and maintenance of colour polymorphism in the shrimp Hippolyte obliquimanus. It includes four chapters that illustrate, in an integrative approach, the ecological and behavioural consequences of different camouflage and habitat use strategies selected in main colour morphs. In the first chapter entitled Camouflage through colour change: mechanisms, adaptive value, and ecological significance, the physiological and structural mechanisms underpinning colour change, and hence camouflage, in different species were detailed within a general framework. Also in this section, both the adaptive value and the ecological and evolutionary implications of these processes were discussed. In the second chapter entitled Shape, colour plasticity, and habitat use indicate morph-specific camouflage strategies in a marine shrimp morph-specific colour change and habitat selection were investigated as potential mechanisms affecting camouflage efficiency and the natural distribution of H. obliquimanus colour morphs between macroalgal habitats formed by Sargassum furcatum and Galaxaura marginata. Moreover, morph-specific morphology and behavioural traits were also assessed. Shrimp showing a homogeneous coloration (H) changed colour when placed in colour-mismatching backgrounds and also exhibited a more robust shape associated to high substrate fidelity and specialization. On the other hand, striped translucent shrimp (ST) were not capable of colour change and showed high mobility, consistent with a more streamlined shape and a generalised use of algal habitats. In the third chapter entitled The adaptive value of camouflage and colour change in a polymorphic shrimp visual models and predation trials were used to test the adaptive value of camouflage and colour change of H. obliquimanus colour morphs against colour-contrasting macroalgae, which provide different levels of colour concealment. The low colour discrimination predicted by a visual model of a seahorse predator for pink shrimp against the red weed Galaxaura was directly translated to lower detection and consumption rates on this morph by captive seahorses in a laboratory experiment, demonstrating the high adaptive value of camouflage in this species. Finally, in the fourth chapter entitled Habitat-dependent niche partitioning between colour morphs of the algal-dwelling shrimp Hippolyte obliquimanus the trophic ecology of H and ST morphs when using Sargassum and Galaxaura habitats were assessed through stable isotope analysis. Morphs showed different isotopic signatures only in Galaxaura, where the supply of food resources are limiting, leading to a tropic niche diversification between H and ST shrimp and a probable relaxation of intra-specific competition. Conversely, in Sargassum, where resources are abundant, morphs coexistence is possible even without niche partitioning. Altogether, the results of this thesis contributed to a better understanding of the adaptive value and the underlying mechanisms controlling for the maintenance of colour polymorphism in H. obliquimanus. From both an ecological and evolutionary perspective, morph-specific strategies of camouflage and habitat use likely promote the stability of shrimp populations in a spatially heterogeneous and markedly seasonal habitat. / Esta tese aborda os mecanismos que regulam a evolução e manutenção do polimorfismo de cor no camarão Hippolyte obliquimanus ao longo de quatro capítulos que ilustram de forma integrada as consequências ecológicas e comportamentais das distintas estratégias de camuflagem e de uso do habitat selecionadas nos principais morfótipos da espécie. No Capítulo 1, intitulado Camouflage through colour change: mechanisms, adaptive value, and ecological significance, são detalhados de maneira geral os mecanismos fisiológicos e estruturais responsáveis pelo processo de mudança de cor e obtenção de camuflagem em diferentes espécies de animais. Nessa seção também é detalhado o valor adaptativo e as implicações ecológicas e evolutivas desses processos. No Capítulo 2, intitulado Shape, colour plasticity, and habitat use indicate morph-specific camouflage strategies in a marine shrimp, são investigados os processos de mudança de cor e de seleção de habitat como possíveis mecanismos reguladores dos padrões de camuflagem e de distribuição dos morfótipos de cor de H. obliquimanus entre os bancos das algas Sargassum furcatum e Galaxaura marginata. Além disso, também são avaliadas diferenças morfológicas e comportamentais entre os morfótipos na utilização dos habitats vegetados. Camarões caracterizados por uma coloração homogênea (H) mudam de cor quando em contato com substratos de coloração diferente à sua, exibindo também uma morfologia mais robusta e um comportamento de alta fidelidade e especialização aos substratos de macroalgas. Por outro lado, camarões transparentes listrados (TL) não mudam de cor e apresentam elevada mobilidade, consistente com uma morfologia mais hidrodinâmica e com uso mais generalizado dos habitats estudados. No Capítulo 3, intitulado The adaptive value of camouflage and colour change in a polymorphic shrimp, são utilizados modelos visuais e experimentos de predação para testar o valor adaptativo da camuflagem e mudança de cor em diferentes morfótipos do camarão H. obliquimanus quando estes estão associados a macroalgas que fornecem diferentes graus de semelhança cromática. O baixo grau de discriminação cromática previsto para camarões rosa em associação à alga vermelha Galaxaura através da modelagem visual de um predador (cavalo-marinho) resultou em baixas taxas de detecção e predação desse morfótipo por cavalos-marinhos em um experimento de laboratório, demonstrando um alto valor adaptativo da camuflagem nessa espécie. Por fim, no Capítulo 4, intitulado Habitat-dependent niche partitioning between colour morphs of the algal-dwelling shrimp Hippolyte obliquimanus, a ecologia trófica dos morfótipos de cor H e TL na utilização dos bancos de Sargassum e Galaxaura é avaliada através de análises de isótopos estáveis. Os morfótipos de cor mostraram diferenças nas razões isotópicas apenas em Galaxaura, onde a abundância de recursos alimentares é limitante, levando à diversificação de nicho trófico entre camarões H e TL e uma provável redução da competição intraespecífica. Por outro lado, em Sargassum, onde há abundância de recursos, a coexistência entre os morfótipos é possível mesmo sem partição de nicho ecológico. Em conjunto, os resultados obtidos nessa tese detalham tópicos centrais sobre os mecanismos reguladores e o valor adaptativo do polimorfismo cromático em H. obliquimanus. Dentro de uma abordagem ecológica e evolutiva, as diferentes estratégias de camuflagem e de uso de habitat dos morfótipos de cor parecem ser essenciais para o equilíbrio populacional da espécie, uma vez que os bancos de macroalgas utilizados como habitat pelos indivíduos são bastante heterogêneos e sua disponibilidade varia sazonalmente.
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Diversidade floral dos m?is da abelha mel?fera africanizada (Apis mellifera Linaeus) do estado do Rio de Janeiro por meio da an?lise melissopalinol?gica / Floral diversity of honeys of africanized honeybee (Apis mellifera Linnaeus) of the state of Rio de Janeiro through melissopalinological analysis

HAIDAMUS, Susana Linhares 06 August 2015 (has links)
Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-07-14T19:27:20Z No. of bitstreams: 1 2015 - Susana Linhares Haidamus.pdf: 4430503 bytes, checksum: 8b067f3310cc073f8b11947a2a31ce98 (MD5) / Made available in DSpace on 2017-07-14T19:27:20Z (GMT). No. of bitstreams: 1 2015 - Susana Linhares Haidamus.pdf: 4430503 bytes, checksum: 8b067f3310cc073f8b11947a2a31ce98 (MD5) Previous issue date: 2016-08-06 / CAPES / The identification of the blossoms in honeys for marketing is a major challenge for the Brazilian beekeeping sector, which requires information on the botanical and geographical origin of honey and also assist in quality control of this bee product. The aim of this study is to identify the plant species that contribute mostly to the production of honey in the state of Rio de Janeiro, to evaluate the floral origin presents on the label is in line with the laboratory method, and check the quality of the product according to the presence of figurative elements. 152 honey samples were acquired in trade from the state of Rio de Janeiro, among informal and legalized brands. The melissopalinological analysis followed the European standard methodology without acetolysis, to identify the pollen types, their percentages in the sample and their arrangement in the frequency classes. Were identified 60 pollen types, belonging to 27 plant families, 34 genera and nine species. Fabaceae and Asteraceae presented the highest diversity of pollen types. Of all pollen types, 31% were more frequent as Eucalyptus sp., Myrcia sp. and Piptadenia sp. According to the predominance of pollen types in the honey samples, 58.5% were honeys classified as unifloral, the major is Eucalipto honey; 35.5% were heterofloral and 8% bifloral. In the melissopalinological analysis there was an important difference in the floral diversity from the report of the samples and from the frequency of sampling. When the floral identification is made from lab and check the brands of the honeys, there was a difference; only 13% from 89 monofloral samples were in agreement with its botanical origin; five were Eucalyptus, three Citrus, two Vernonia and two Gochnatia. The analysis of the figurative elements in the honey samples, either biological origin or dust, was high (73% of samples). In the sampling, 58% did not obey the standards and quality of honey, due to the presence of microorganism and distiness. / A identifica??o das floradas dos m?is comercializados ? um importante desafio para o segmento ap?cola brasileiro, que requer informa??es sobre a origem bot?nica e geogr?fica do mel e tamb?m por auxiliar no controle de qualidade deste produto da abelha. O objetivo do presente trabalho ? identificar as esp?cies vegetais que mais contribuem para a produ??o de mel no estado do Rio de Janeiro, verificar se a nomina??o da origem floral no r?tulo est? em conson?ncia com o m?todo de laborat?rio, e verificar a qualidade do produto por meio da presen?a de elementos figurativos. Foram avaliadas 152 amostras de m?is do com?rcio do estado do Rio de Janeiro, dentre marcas informais a legalizadas. A an?lise melissopalinol?gica seguiu a metodologia padr?o europ?ia, sem uso de acet?lise, para a identifica??o dos tipos pol?nicos, de suas porcentagens na amostra e da disposi??o em classes de frequ?ncia. Foram identificados 60 tipos pol?nicos, pertencentes a 27 fam?lias, 34 g?neros e nove esp?cies. Fabaceae e Asteraceae apresentaram a mais alta diversidade em tipos pol?nicos. Do total de tipos pol?nicos, 31% foram mais frequentes como, Eucalyptus sp., Myrcia sp. e Piptadenia sp. Segundo a predomin?ncia dos tipos pol?nicos nas amostras, 58,5% foram do tipo monofloral, sendo o mel de Eucalipto o mais predominante; 35,5% do tipo heterofloral e 8%, biflorais. H? importante diferen?a na diversidade floral pela an?lise melissoplanol?gica de laudo das amostras e das frequ?ncias na amostragem. A identifica??o floral pelo m?todo de laborat?rio diverge da presente no r?tulo, apenas 13% das 89 amostras tipo monofloral no r?tulo, estavam em concord?ncia com sua origem bot?nica; cinco eram de Eucalyptus, tr?s de Citrus, duas de Vernonia e duas de Gochnatia. A presen?a de elementos figurativos, sejam de origem biol?gica ou sujidades, foi alta (73% das amostras). Das amostras, 58% estavam fora dos padr?es de identidade e qualidade do mel, devido ? presen?a de microrganismos e sujidades.
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Foraging Ecology and Stress in Sea Turtles

Chelsea E Clyde-Brockway (6823772) 13 August 2019 (has links)
As ectothermic marine megafauna, sea turtle physiology and ecology are tightly intertwined with temperature, seasonality, and oceanography. Identifying how turtles respond when exposed to cold water, how they adapt to cold environments when they need to explore cold environments in order to forage, and what foraging resources are exploited by sea turtles are all components central to their conservation. Cold-stunning is a well-documented phenomenon that occurs when water induced decreases in sea turtle body temperature cause turtles to become immobilized and wash ashore. While most cold-stunned turtles are rescued and rehabilitated, we do not know whether cold-stunning is an acute transient occurrence, or a symptom of a bigger environmental problem. Further, while in some environments avoiding cold water is preferential, in other habitats, sea turtles need to inhabit cold environments in order to forage. Along the Eastern Pacific Rim, discrete upwelling locations are characterized by high primary productivity and unusually cold water. In these environments, avoidance is not possible and sea turtles require physiological adaptions to mitigate body temperature decreases in cold water. Little is known about how turtles handle upwelling environments, despite the fact that sea turtles remain in these habitats regardless of water temperature fluctuations. Because upwelling habitats provide increased nutrient presence, and sea turtles are opportunistic foragers, quantification of diet composition will further our understanding of why sea turtles remain in cold water environments year-round. Diet composition in multiple populations of cohabitating sea turtles revealed partitioning that results in reduced inter-specific competition. Further, flexibility in diets provides a wide range of ecosystem services central to habitat resiliency. Therefore, conservation of endangered sea turtles requires complete ecosystem conservation, and complete understanding of the interconnectivity of sea turtles and their environments is crucial.<br>

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