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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

Interactions of seasonally changing physical factors and grazing affecting intertidal communities on a rocky shore

Cubit, John David, 1944- 03 1900 (has links)
Thesis (Ph.D.)--Oregon, Dept. of Biology Vita Bibliography: l. 118-122
2

The distribution and zonation of intertidal organisms of rocky coasts in south eastern Australia /

King, R. J. January 1972 (has links)
Thesis (Ph. D.)--University of Melbourne, 1972. / Includes appendices. Includes bibliographical references (p. 243-263).
3

Rocky intertidal zonation and habitat ecology of gammaridean Amphipods in Long Island Sound /

Chavanich, Suchana. January 1997 (has links)
Thesis (M.A.)--Central Connecticut State University, 1997. / Thesis advisor: Dr. Kim A. Wilson. " ... in partial fulfillment of the requirements for the degree of Master of Arts in Biology." Includes bibliographical references (leaves 47-56).
4

Estrutura da comunidade macrobentônica intertidal em praias invadidas pelo bivalve Isognomon bicolor (C.B. Adams, 1845) (Mollusca: Pteriidae) no Nordeste brasileiro

Queiroz, Romilda Narciza Mendonça de 27 February 2015 (has links)
Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2016-02-29T13:38:50Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) PDF - Romilda Narciza Mendonça de Queiroz.pdf: 1184612 bytes, checksum: c662ab49132bf777a48debcd6101143e (MD5) / Approved for entry into archive by Secta BC (secta.csu.bc@uepb.edu.br) on 2016-04-12T17:18:00Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) PDF - Romilda Narciza Mendonça de Queiroz.pdf: 1184612 bytes, checksum: c662ab49132bf777a48debcd6101143e (MD5) / Made available in DSpace on 2016-04-12T17:18:00Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) PDF - Romilda Narciza Mendonça de Queiroz.pdf: 1184612 bytes, checksum: c662ab49132bf777a48debcd6101143e (MD5) Previous issue date: 2015-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The invasive bivalve Isognomon bicolor is native to the Caribbean Sea and today is among the key invasive marine species in coastal habitats of the Brazilian coast. Before this problem, this study aims to characterize the structure of the macrobenthic community on beaches in the presence Isognomon bicolor and assess whether their presence may be influencing or being influenced by the distribution and density of native species. The study was conducted in the rocky beaches of Carapibus and Jacumã, Paraíba state (NE Brazil). On Carapibus beach were recorded the highest densities of the invasive I. bicolor (300 ind/m 2 ) and native benthic species (11,372.22 ind/m²). Density of I. bicolor was highest in the mesolittoral zone (347.68 ind/m²) in the rainy season (158.56 ind/m²). However, there was no difference in benthic communities of these beaches between the dry and rainy periods (p = 0.054), but beaches (p = 0.001) and mesolittoral zones (p = 0.005) were significantly different. In characterizing the distribution and zoning of the benthic community, it was observed that in the upper mesolittoral zone these two beaches, the dominant species was the bivalve Brachidontes exustus and the microgastropod Echinolittorina lineolata, and the barnacle Chthamalus sp. In the lower mesolitoral zone, B. exustus, Chthamalus sp., and I. bicolor were the main differentiating factors of the observed zonation. It was also a positive correlation between the density of I. bicolor and some native species. With the results obtained, it can be concluded that certain benthic macroinvetebrates, structural characteristics and benthic cover of the studied beaches are influencing the density and distribution of I. bicolor. / A invasão por espécies exóticas tem causado um grande impacto sobre os ecossistemas, além de prejuízos econômicos, sociais e à saúde humana. Espécie exótica invasora é aquela que foi introduzida a partir de outro ambiente, se estabeleceu, e constitui uma ameaça a biodiversidade nativa, aos recursos naturais ou a saúde humana. O bivalve Isognomon bicolor é uma espécie originária do Caribe e desde seu primeiro registro em 1994, esta espécie tem se expandido e hoje está entre as principais espécies marinhas invasoras que tem causado impactos nas comunidades entremarés na costa brasileira. Mudanças no padrão de distribuição, na disponibilidade de alimento e no tamanho ou estrutura dos substratos e refúgios tem sido ocasionadas pelo I. bicolor. Provavelmente I. bicolor foi introduzido de maneira involuntária na costa do Rio de Janeiro (Sudeste do Brasil) via incrustações em plataformas de petróleo ou nos cascos de navios, e atualmente ele tem sido registrado do litoral do Nordeste até o Sul do país. Para que uma invasão seja bem sucedida, o invasor deve possuir estratégias eficientes para a ocupação do ambiente e tolerância aos fatores abióticos. No caso do I. bicolor, sabe-se que a influência da hidrodinâmica local, temperatura, estrutura do substrato e associação com espécies nativas podem favorecer o estabelecimento deste invasor. Apesar disso, o conhecimento sobre a ecologia e distribuição espaço-temporal do I. bicolor ainda é escasso, principalmente para a região Nordeste do país, que possui características e condições ambientais diferentes dos locais onde ele tem sido estudado. Há muitos questionamentos que ainda precisam ser esclarecidos acerca dos impactos causados por esta espécie e dos fatores que permitem sua expansão relativamente rápida pelos ambientes costeiros no Brasil. Neste contexto, este estudo tem como objetivo principal caracterizar a estrutura da comunidade macrobentônica em praias com a presença do bivalve invasor Isognomon bicolor e avaliar se sua presença pode estar influenciando ou sendo influenciada pela distribuição e densidade das espécies nativas. Os dados fornecidos poderão nortear a elaboração de medidas de controle desta espécie invasora.
5

The distribution and zonation of intertidal organisms of rocky coasts in south eastern Australia

King, Robert John Unknown Date (has links) (PDF)
The intertidal flora and fauna of S.E. Australia (Robe, South Australia to S. New South Wales, including Tasmania) is described in terms of its horizontal and vertical distribution. A detailed account of intertidal zonation, on the central Victorian coast and Bass Strait islands, is included. Environmental features are discussed and sea temperature data for Pt. Lonsdale is presented. / Analysis of the marine flora in S.E. Australia suggests that the concept of separate biogeographic provinces in this region is invalid and the flora is best interpreted as a continuum.
6

The distribution and zonation of intertidal organisms of rocky coasts in south eastern Australia

King, R. J. January 1972 (has links)
Thesis (Ph. D.)--University of Melbourne, 1972. / Includes bibliographical references.
7

The structure of experimental clastic-substrate marine communities

Evans, Wayne Aloysius 01 January 1976 (has links)
It is hypothesized that difference between containers and between sediments will produce structural differences in the resulting communities by intensifying competition for resources, and by excluding certain classes of predators. It is also hypothesized that the level of the effect of container, substrate, and time on community structures will be dependent on tidal level. Paine (1969) and Dayton (1972) have demonstrated that the structure of some communities is largely determined by the effects of foundation, or keystone, species. It is suggested that the structure of classic-substrate communities may be determined similarly.
8

Effects of Intertidal Position on the Capacity for Anaerobic Metabolism and Thermal Stress Response in the Common Acorn Barnacle, Balanus glandula

Anderson, Kyra 01 February 2022 (has links) (PDF)
Intertidal habitats are characterized by dynamic, tidally-driven fluctuations in abiotic and biotic factors. Many of the environmental stressors that vary across the intertidal (e.g., temperature, oxygen, food availability, predation pressure) are strong drivers of metabolic rate in ectotherms. As such, we predicted that there may be pronounced differences in the metabolic and stress physiology of conspecific sessile invertebrates occupying at different relative tidal heights. The common acorn barnacle Balanus glandula represents an ideal model organism in which to investigate the possibility of tidal height-dependent physiological differences, owing to their wide distribution in the intertidal zone and their eurytolerant nature. In the first chapter of my thesis, we investigate the hypothesis that B. glandula anchored in the low intertidal have a greater capacity for anaerobic metabolism than conspecifics in the high intertidal, and that this is due to increased predation pressure during submersion. Further, we explore the temporal and spatial fidelity of certain tidal-height driven trends in lactate dehydrogenase activity previously observed in our lab (i.e., higher LDH activity in low intertidal barnacles; Horn et al., 2021), and attempt to identify environmental variables that drive plasticity in LDH activity. We found that, in general, there were higher densities of B. glandula and gastropod whelk predators in the low intertidal compared to the high intertidal, but follow-up studies in the lab revealed that opercular closure in B. glandula was induced by predator exposure (Acanthinucella spirata) for less than 24h. This time frame for shell closure is unlikely to result in internal hypoxia or enhance capacity for anaerobic metabolism. We were therefore not surprised to find that LDH activity in B. glandula was likewise not affected by predator exposures (48h) carried out in the lab. After failing to find an effect of predators on LDH activity in B. glandula, we attempted to replicate the previous finding that LDH activity was highest in low intertidal populations of B. glandula. We did this at the original location in San Luis Obispo Bay, CA as well as at three novel field sites and across seasons and years. While we did observe variation in LDH activity over time and between sites, we did not consistently observe the same trend in LDH activity whereby low intertidal barnacles had the highest activity. In response to these variable patterns, we attempted to identify what environmental parameters, other than predation, might be responsible for plasticity in LDH activity. Unfortunately, neither temperature nor emersion stress – the two variables we examined – had any significant an effect on LDH activity in B. glandula. These data suggest that there must be multiple, interacting stressors – including tidal position - that influence the anaerobic metabolic capacity of B. glandula. In the second chapter of my thesis, we went on to investigate how the response to thermal stress might differ between populations of B. glandula from different vertical heights in the intertidal zone. To this end, we assessed how aerial temperature stress affected oxygen consumption rates (MO2), superoxide dismutase (SOD) activity, and time to mortality in B. glandula collected from both low and high intertidal positions. We found that barnacles from the low intertidal showed a significant increase in MO2 with higher temperature, while MO2 was unaffected by temperature in B. glandula from the high intertidal. We also observed that SOD activity levels were higher in the high intertidal barnacles compared to the low intertidal barnacles, although neither group was increasing SOD activity under higher temperature. Finally, we observed significantly longer survival times during thermal stress in barnacles from the high intertidal zone (e.g., LT50 = 8.75 h vs 5 h at 33˚C for the high and low barnacles, respectively), although this advantage seemed to be lost with the addition of desiccation stress at these same temperatures. It is evident that life in highest reaches of the intertidal zones is physiologically challenging, and this has resulted in a population of B, glandula barnacles that are less sensitive to and better suited to tolerate temperature extremes than conspecifics in the lowest intertidal regions. Understanding how habitat variation may differentially impact the metabolic and thermal stress physiology of B. glandula is increasingly important as climate change progresses. This is particularly significant considering that organisms in the intertidal already reside within a relatively stressful environment and may be living closer to their thermal tolerance limits than animals from less extreme habitats.
9

ZONATION AND PHENOLOGY OF THREE SPECIES OF SARGASSUM IN THE INTERTIDAL ZONE OF THE NORTHERN GULF OF CALIFORNIA.

MCCOURT, RICHARD MATTHEW. January 1983 (has links)
Three species of Sargassum are the P10st abundant intertidal macroalgae at Puerto Penasco, Sonora, Mexico. Sargassum johnstonii Setchell & Gardner, S. herporhizum Setchell & Gardner, and S. sinicola Setchell & Gardner var. camouii (Dawson) Norris & Yensen are zoned on emergent reef in low intertidal areas. Sargassum johnstonii occurs in a zone above dense stands of S. herporhizum, and scattered patches of S. 8inicola occur on the lowest emergent reef. Sargassum sinicola, the most abundant species, predominates in pools throughout the intertidal zone. In mid-intertidal pools the species show the same zonation with respect to water depth that they do on emergent reef. Ecological separation is clear, the species occurring in different vertical zones or different habitats (pools or emergent reef). At some sites where S. herporhizum is rare or absent, the upper limit of emergent S. sinicola plants shifts upward probably because of a combination of physical and biological factors. The three species in this highly seasonal region reach maximum size and canopy cover in early spring. All produce fertile receptacles in the spring and shed their branches and die back in summer. Surviving S. sinicola persist through the summer at larger sizes, recommence growth and produce a second crop of receptacles in the fall; the other two species grow but are not fertile until the following spring. The species differ in allocation of biomass to vegetative and sexual reproductive structures. Sargassum herporhizum invests a high proportion of its wet and dry biomass into extensively branched, rhizoidal holdfasts. The holdfasts of the other two species are smaller relative to their upper branches, and are not rhizoidal. Experimental clearings showed that S. herporhizum was the most effective at recovering continuous space after disturbance and also after normal summer dieback. Sargassum johnstonii and S. sinicola produce large volumes of sexual receptacles on buoyant branches, which have the potential for wide dispersal, whereas S. herporhizum produces a relatively small volume. A trade-off between short-range vegetative encroachment abilities and potential for long-range dispersal of sexual propagules may have occurred in the evolution of reproductive strategies of these Sargassum species.
10

Estrutura populacional e variabilidade genetica de anemonas-do-mar da região entremares de costão rochoso / Population structure and genetic variability of sea anemones from the intertidal rocky shore

De Capitani, Joana Dutilh 08 January 2007 (has links)
Orientadores: Luiz Francisco Lembo Duarte, Vera Nisaka Solferini / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-09T03:13:57Z (GMT). No. of bitstreams: 1 DeCapitani_JoanaDutilh_M.pdf: 5636529 bytes, checksum: 9756e9e22fb0418a7a5cd700c6e0c60d (MD5) Previous issue date: 2007 / Resumo: A riqueza de espécies, abundância, proporção de jovens, crescimento corporal, seleção de microhabitat, diversidade genotípica, variabilidade e estrutura genética de anêmonas-do-mar da região entremarés foram estudados no período de agosto de 2005 a julho de 2006. Cinco espécies foram encontradas e tiveram as suas populações acompanhadas em duas praias do município de São Sebastião, SP: Bunodosoma caissarum, Bunodosoma cangicum, Anthopleura cascaia, Actinia bermudensis e Phyllactis flosculifera. Destas, as mais abundantes foram Bunodosoma caissarum, Bunodosoma cangicum e Anthopleura cascaia. Estas três espécies mostraram oscilações muito grandes em seus tamanhos populacionais, padrão não esperado considerando a longevidade de anêmonas-do-mar. As espécies B. caissarum e B. cangicum mostraram um padrão de recrutamento aparentemente contínuo e pequeno enquanto A. bermudensis e A. cascaia apresentaram um maior número de jovens principalmente na primavera. Não foi verificado um padrão claro de crescimento corporal das espécies estudadas, devido, possivelmente, à variação no número de indivíduos amostrados em cada mês, ou a uma taxa de crescimento muito pequena para ser detectada no período de um ano. Os microhabitats ocupados pelas espécies foram significativamente relacionados às suas preferências, mostrando que a localização espacial não acontece aleatoriamente. Bunodosoma caissarum, B. cangicum e Phyllactis flosculifera foram as espécies escolhidas para as análises genéticas. Cada uma delas teve duas populações amostradas, e as populações de B. caissarum foram também organizadas localmente em subgrupos. As três espécies apresentaram altos valores de diversidade genética e todas as populações apresentaram déficits de heterozigotos. Os valores de diferenciação genética encontrados para B. caissarum (? = 0.039) são significativos, considerando que a espécie apresenta larva planctônica e as populações amostradas estavam separadas por apenas 13 km. Além disso, foi encontrada evidência de estruturação microgeográfica para esta espécie. Bunodosoma cangicum apresentou valores baixos de estruturação genética (? = 0.021) e P. flosculifera valores moderados (? = 0.080). Phyllactis flosculifera e B. cangicum apresentam populações distantes (1000 km e 1300 km, respectivamente) geneticamente conectadas, o que sugere que ambas as espécies tenham larvas com capacidade de dispersão em grandes distâncias. Todos os indivíduos das populações estudadas das três espécies apresentaram genótipos únicos, o que sugere que nenhuma delas tenha reprodução assexuada / Abstract: We studied the richness of species, abundance, proportion of juveniles, growth, microhabitat selection, genotypic diversity, genetic variability and structure of intertidal sea anemones between August 2005 and July 2006. Five species were found and their populations were studied in São Sebastião, SP: Bunodosoma caissarum, B. cangicum, Anthopleura cascaia, Actinia bermudensis and Phyllactis flosculifera. The most abundant ones were Bunodosoma caissarum, B. cangicum and Anthopleura cascaia. These three species showed important oscillations in their populations sizes, a pattern that was not expected considering the long life of sea anemones. Bunodosoma caissarum and B. cangicum showed small and continuous recruitment, while A. bermudensis and A. Cascaia presented a bigger number of juveniles mainly in the spring. A clear pattern of growth was not observed for any of the species studied, probably due to the variation in populations¿ size during the study or it could have been caused by a growth rate too small to be detected in one year time. The microhabitats occupied by all five species were related to their preferences, indicating that the spatial distribution found was not at random. Bunodosoma caissarum, B. cangicum and P. flosculifera were also genetically analyzed. Each one of them had two populations sampled, and the ones of B. caissarum were sampled in subgroups following spatial distribution in situ. All the species showed high levels of genetic diversity and all the populations presented a deficit of heterozygotes. The values of genetic differentiation found for B. caissarum (? = 0.039) are significant given the long-lived planktonic larva of the species and the small distance between the samples (13 km) and we also found evidence of microgeographic structuring in this species. Bunodosoma cangicum showed low levels of genetic structuring (? = 0.021) while P. flosculifera presented a moderate value of structuring (? = 0.080). Phyllactis flosculifera and B. cangicum present distant populations (1000 km and 1300 km apart, respectively) genetically connected suggesting that both species have larvae capable of good dispersal distances. All of the individuals of the three species showed unique genotypes, suggesting that none of them have asexual reproduction / Mestrado / Ecologia / Mestre em Ecologia

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