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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.
101

Variabilidade fenot?pica e genot?pica do camar?o Macrobrachium jelskii (Miers, 1877) das Bacias do Nordeste Brasileiro: uma abordagem de sistem?tica integrativa

Moraes, S?vio Arcanjo Santos Nascimento de 21 February 2017 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-06-02T22:53:27Z No. of bitstreams: 1 SavioArcanjoSantosNascimentoDeMoraes_DISSERT.pdf: 3382313 bytes, checksum: d29b0d639c0367f1cb819ebeb2afb377 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-06-09T22:09:38Z (GMT) No. of bitstreams: 1 SavioArcanjoSantosNascimentoDeMoraes_DISSERT.pdf: 3382313 bytes, checksum: d29b0d639c0367f1cb819ebeb2afb377 (MD5) / Made available in DSpace on 2017-06-09T22:09:38Z (GMT). No. of bitstreams: 1 SavioArcanjoSantosNascimentoDeMoraes_DISSERT.pdf: 3382313 bytes, checksum: d29b0d639c0367f1cb819ebeb2afb377 (MD5) Previous issue date: 2017-02-21 / Macrobrachium jelskii ? uma esp?cie de ampla distribui??o no nordeste brasileiro, e ocorrendo em toda Am?rica do Sul. Contudo, nenhum estudo acerca a filogeografia, varia??es morfol?gicas locais e variabilidade gen?tica das popula??es desta esp?cie foi efetuado. Esta esp?cie de camar?o, pode revelar informa??es importantes sobre o padr?o de dispers?o e vicariantes correlatos ? cen?rios de arranjos tect?nicos pret?ritos e outros eventos que possam ter influenciado a biogeografia dos taxa aqu?tico. Portanto, o presente trabalho tem como objetivo investigar a diversidade fenot?pica e molecular das popula??es do camar?o Macrobrachium jelskii, nas ecorregi?es Nordeste M?dio Oriental, Maranh?o Piau? e S?o Francisco, frente a influ?ncia de cen?rios pret?ritos e respostas ambientais locais. Este trabalho utilizou uma abordagem de Sistem?tica integrativa, a morfometria geom?trica multivariada, an?lises filogen?ticas e de estrutura??o gen?tica. A morfometria geom?trica, revelou dimorfismo sexual evidente, em que f?meas apresentaram cefalot?rax e abd?men mais estirados horizontalmente. Isto, possivelmente, favorece o desenvolvimento gonadal, vitelog?nese e armazenamento dos ovos. Abstra??o da forma dos tr?s planos corporais n?o demostrou um consenso acerca da estrutura??o das popula??es entre de M. jelskii no Nordeste Brasileiro. Tal fato corrobora com a baixa diversidade nucleot?dica e haplot?pica, em que foi relatado apenas um hapl?tipo compartilhado entre as popula??es das bacias. Assim, ratificando a possibilidade de introdu??o da esp?cie nos corpos d??gua do Nordeste pelo DNOCS. Em adi??o, os dados gen?ticos relataram a presen?a de ru?dos e picos duplos no eletroferograma, que representa co-amplifica??o de pseudogenes mitocondriais da regi?o Citocromo Oxidase I, pouco relatadas na literatura para o g?nero Macrobrachium. Este fato abre um precedente de desconfian?a para rela??es filogen?ticas e filogeogr?ficas publicadas, recentemente que n?o retratam isto. Sabendo que esta caracter?stica pode gerar uma superestima??o de linhagens evolutivas e, assim, conclus?es err?neas sobre eventos dispersivos, vicariantes ou de especia??o, se faz de suma import?ncia retratar os casos de pseudogenes e a utiliza??o de iniciadores espec?ficos para cada t?xon. / Macrobrachium jelskii is a widely distributed species in northeastern Brazil, occurring throughout South America. However, no studies on phylogeography, local morphological variations and genetic variability of the populations of this species were carried out. This prawn species can reveal important information on the dispersion pattern and related vicariates for scenarios of past tectonic arrangements and other events that have influenced the biogeography of the aquatic taxa. The aim of this manuscript is to investigate a phenotypic and molecular diversity of the prawn M. jelskii populations in the Mid-Northeast Caatinga, Maranho Piau? and S?o Francisco ecoregions, influenced by past scenarios and environmental local responses. This scientific article uses an approach of Integrative Systematics, a multivariate geometric morphometry, phylogenetic analyzes and genetic structuring. Geometric morphometry showed evident sexual dimorphism, in which females presented cephalothorax and abdomen more horizontally stretched. This possibly favors gonadal development, vitellogenesis and egg storage. Abstraction of the shape of the three body planes does not demonstrate a consensus on the structuring of the populations between M. jelskii in the Northeast of Brazil. This fact corroborates a low nucleotide and haplotype diversity, in which only one haplotype was shared among the populations of the basins. Thus, ratifying a possibility of introduction in the Northeast area by DNOCS. In addition, the genetic data reported a presence of noises and double peaks not electropherogram, which represents co-amplification of mitochondrial pseudogenes of the region Cytochrome Oxidase I, little reported in the literature for the genus Macrobrachium. This fact show a precedent of mistrust for published phylogenetic and phylogeographic relationships, which recently did not depict this. Knowing that this characteristic can generate an overestimation of evolutionary lineages and, thus, erroneous conclusions on dispersive, vicarious or speciation events, it is of importance to report the cases of pseudogenes and the use of specific molecular primers for each taxon.
102

Utilities of Extinct and Extant Marine Arthropod Cuticle

Tashman, Jessica Nichole 14 July 2022 (has links)
No description available.
103

Ecologia populacional do caranguejo Dissodactylus crinitichelis Moreira, 1901 (Crustacea: Decapoda) e seu hospedeiro Encope emarginata Leske, 1778 (Echinodermata: Clypeasteroidea) no litoral nordestino brasileiro

CUNHA , Aislan Galdino da 11 August 2015 (has links)
Submitted by Irvana Coutinho (irvana@ufpa.br) on 2017-05-05T16:17:39Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese_EcologiaPopulacionalCaranguejo.pdf: 1818740 bytes, checksum: b1b855b89bfd8d317a66e33be32d2be6 (MD5) / Approved for entry into archive by Irvana Coutinho (irvana@ufpa.br) on 2017-05-05T16:17:59Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese_EcologiaPopulacionalCaranguejo.pdf: 1818740 bytes, checksum: b1b855b89bfd8d317a66e33be32d2be6 (MD5) / Made available in DSpace on 2017-05-05T16:17:59Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Tese_EcologiaPopulacionalCaranguejo.pdf: 1818740 bytes, checksum: b1b855b89bfd8d317a66e33be32d2be6 (MD5) Previous issue date: 2015-08-11 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Esta tese apresenta informações a respeito dos efeitos das variáveis ambientas sobre a ecologia populacional do caranguejo Dissodactylus crinithichelis e seu hospedeiro Encope emarginata e as influências que as bolachas-da-praia exercem sobre a população do caranguejo no litoral nordestino brasileiro. Foram realizadas amostragens biótica e abiótica, ao longo de nove praias que compõem o litoral pernambucano, que faz parte do Atlântico Sul-ocidental. A granulometria foi a variável abiótica com maior influência sobre as duas espécies. As bolacha-da-praia tendem a ocupar, com maior densidade, a costa norte de Pernambuco, sendo as fêmeas adultas a maioria da população. O período de recrutamento foi descrito para agosto e maio. Os indivíduos de bolacha-da-praia apresentaram maior densidade nas classes de comprimento intermediária, com destaque para os comprimentos de 10 à 12 cm. As bolachas-da-praia não apresentaram crescimento polifásico, com alometria negativa. Em relação aos parâmetros populacionais de D. crinitichelis, residindo nas bolachas-da-praia, não foi observado variação ao longo dos meses do ano. Os caranguejos também apresentaram maior densidade nas praias do litoral norte. Houve um domínio de machos nos meses do período de estiagem, enquanto que de fêmeas no período chuvoso. Foi observado recrutamento de indivíduos juvenis ao longo de todo ano, com um pico no mês de maio. A espécie apresentou elevada correlação entre os indivíduos juvenil, imaturo e macho adulto, com crescimento polifásico, com alometria positiva juvenis, imaturos e machos adultos, assim como para as fêmeas adultas, com maior evidenciamento da alometria positiva. Em relação da influência de E. emarginata sobre a população de D. crinitichelis, foi verificado que os caranguejos apresentam habitam com maior intensidade as bolachas-da-praia adultas, em suas classes intermediárias. No entanto, quando essas encontram-se ocupadas, as bolachas-da-praia imaturas podem ser ocupadas pelos caranguejos. Observou-se uma diminuição na densidade dos estágios subsequentes dos caranguejos, independente dos estágio de desenvolvimento da bolacha-da-praia. Foi observado uma maior abundância de caranguejos machos, nas classes de área da bolacha-da-praia. Desta forma, o presente trabalho contribui com informações sobre a biologia populacional de E. emarginata e D.crinitichelis, além de contribuir com papel que uma espécie exerce sobre a outra. Visto que, são espécies bioturbadoras da camada superficial do sedimento marinho, com função de manutenção da trofia nas praias arenosas, tanto para as espécies residentes como para as espécies visitantes. Sendo estas áreas como locais de manutenção das populações circunvizinhas de caranguejo D. crinitichelis como da bolacha-da-praia E. emarginata. E de relevante interesse a ecologia das populações, pesca subsistência da população ribeirinha e lazer da população humana.
104

Evolutionary and Population Dynamics of Crustaceans in the Gulf of Mexico

Timm, Laura 07 June 2018 (has links)
Evolution occurs and can be conceptualized along a spectrum, bounded on one extreme by the relationships between deep lineages – such as phyla, classes, and orders – and on the other by the molecular dynamics of operational taxonomic units within a species, defined as population genetics. The purpose of this dissertation was to better understand the evolutionary and population dynamics of crustaceans within the Gulf of Mexico. In the second chapter of my dissertation, I provide a guide to best phylogenetic practice while reviewing infraordinal relationships within Decapoda, including the promise held by next-generation sequencing (NGS) approaches such as Anchored Hybrid Enrichment. Chapter III is a phylogenetic study of species relationships within the economically important shrimp genus, Farfantepenaeus, targeting three mitochondrial genes and uncovering an intriguing pattern of latitudinal speciation. As the first inclusive molecular phylogeny of the genus, we find support for the newly described species F. isabelae, but a lack of support for the species status of F. notialis. Additionally, our results suggest the existence of two distinct subspecies of F. brasiliensis. Chapter IV investigates the relative impacts of habitat heterogeneity and the presence of a possible glacial refugium in determining population dynamics of the Giant Deep-Sea Isopod, Bathynomus giganteus in the northern Gulf of Mexico. Through hybrid population genetics/genomics analyses and Bayesian testing of population models, we find strong evidence for habitat heterogeneity determining population dynamics for this charismatic deep-sea invertebrate. Chapter V further investigates the role of environment in determining and maintaining genetic diversity and population connectivity, specifically focused on establishing biological baselines with which we can diagnose health and resilience of the Gulf of Mexico. This was accomplished through a comparative NGS population genomics study of three species of mesopelagic crustaceans: Acanthephyra purpurea, Systellaspis debilis, and Robustosergia robusta. While diversity and connectivity differs in each species, the comparative results bespeak the importance of access to the Gulf Loop Current in determining and maintaining population dynamics. Overall, my work significantly contributes to our knowledge of Crustacea at the phylogenetic- and population genetic-level.
105

The condition at settlement of the western rock lobster, Panulirus cygnus George : spatial and temporal fluctuations

Limbourn, Andrew John January 2010 (has links)
The condition at settlement of the western rock lobster pueruli presumably reflects both their energetic condition in reaching the near shore and subsequent recruitment into adult populations. In recruiting to the near shore the pueruli swim across the continental shelf where oceanographic conditions are complex and likely influence the success of recruitment. The results from the biochemical studies are interpreted in light of the oceanography off the coast of Western Australia. I investigated the nutritional condition of larval phyllosomata, post-larval puerulus and first instar post-pueruli juveniles of the spiny lobster, Panulirus cygnus, to determine energy use during the non-feeding transitional puerulus stage. Biochemical analyses of lipid, fatty acid (FA) and protein revealed that lipid, in particular phospholipids, is primarily used for energy during the nonfeeding puerulus stage. Monounsaturated FA showed the greatest decline with development, whereas the polyunsaturated FA showed a high degree of sparing, suggesting these FA are not used as a substrate for energy production. The knowledge gained on the biochemistry of energy use in P. cygnus was then used to investigate the spatial and temporal variability in the nutritional condition, in particular lipid condition, of puerulus collected at three near shore locations (Alkimos, Jurien Bay and Dongara) along the Western Australia coast, and one offshore location (Houtman Abrolhos Islands). The one offshore location was chosen as I hypothesised that arriving pueruli are likely to be in a better state of nutrition than those arriving at more coastal locations where the potential journey from offshore larval feeding grounds to the near shore is considerably greater. This element of my research showed lipid levels to be inversely related, generally, to shelf width but were variable, suggesting pueruli may travel complex trajectories to reach nearshore settlement. The lipid and FA composition of pueruli was also consistent with spatial and seasonal variation in Leeuwin Current and coastal productivity regimes.
106

Recruitment of larvae of the ghost shrimp, Callianassa californiensis (Crustacea, Decapoda), in the South Slough Estuary, Oregon

Pimentel, Gliceria Estandian January 1986 (has links)
x, 53 leaves : ill., map ; 29 cm Notes Typescript Thesis (M.S.)--University of Oregon, 1986 Includes vita and abstract Bibliography: leaves 48-53 Another copy on microfilm is located in Archives
107

Spatial and temporal patterns in the population and the feeding of Palaemon peringueyi (MacPherson 1990) (Decapoda, Palaemonidae) in the Kariega estuary, South Africa

Nyalungu, Nonhlanhla Precotia Dudu January 2013 (has links)
The spatial and temporal patterns in the population demographs and feeding ecology of the caridean shrimp, Palaemon peringueyi, was investigated over a 12 month period in the permanently open Kariega Estuary situated on the south-east coastline of South Africa. Shrimps were sampled monthly from three stations corresponding to the lower, middle and upper reaches of the Kariega Estuary. The shrimps were collected at the different stations using a pull net. Temperature, salinity, dissolved oxygen and % cover of submerged vegetation were measured at each sampling station. Finally, the feeding ecology of the shrimp was investigated employing stable carbon (δ¹³C) and nitrogen (δ¹⁵N) isotopes analysis. Temperature, salinity, dissolved oxygen and vegetation cover showed distinct seasonal patterns. The shrimps attained total abundances and biomass of between 0 and 245.6 individuals per m² (ind.m⁻²) and between 0 and 13.6 grams wet weight per m² (g wwt.m⁻²), respectively. Mean abundance ranged between 2.3 (± 3.0) and 88 (± 27.3) ind.m⁻² in the lower reach, between 0.9 (± 0.4) to 21.5 (± 4.5) ind.m⁻² in the middle reach and 0 to 1.6 (± 0.5) ind.m⁻² in the upper reach. Mean biomass ranged between 0.4 (± 0.5) and 4.4 (± 1.4) g wwt.m⁻² in the lower reach, between 0.1 (± 0) to 4.3 (± 0.9) g wwt.m⁻² in the middle reach and between 0 to 1.6 (± 0.5) g wwt.m⁻² in the upper reach. Greatest abundances and biomasses were recorded in winter following heavy rainfall within the catchment area. Freshwater inflow which is due to rainfall is thought to provide a cue for the recruitment of marine breeding organisms. The spatial patterns in the distribution of the shrimps showed that juveniles occupied the lower and middle reaches and adults the entire length of the estuary. There were no significant relationships between the abundance and biomass of the shrimps and the selected physico-chemical variables (p > 0.05 in all cases). Results of the stable isotope study indicated that the mean δ¹³C of the shrimps in the lower, middle and upper reaches were -12.4 (± 1.3) ‰, -15.6 (± 0.5) ‰ and -17.5 (± 0.5) ‰, respectively. The δ¹⁵N isotopes of the shrimps in the lower reach was 11.6 (± 0.5) ‰ with middle and upper reaches having similar δ¹⁵N values, 13.5 (± 0.4) ‰ and 13.4 (± 0.4) ‰, respectively. There was no significant difference in the δ¹³C and δ¹⁵N isotope (p > 0.05) between the sexes of the shrimps. Two-way ANOVA indicated a significant difference in the δ¹³C isotope of the shrimps between the sites (p < 0.05). The difference in the δ¹³C and δ¹⁵N ratios of the shrimps suggests spatial variability in the diet of P. peringueyi within the Kariega Estuary. The diet of the shrimps in the lower reach is primarily composed of Nanozostera capensis epibionts. In the middle reach the diet of the shrimps is likely comprised of the detritus of benthic algae. In the upper reach of the estuary, P. peringueyi likely derives its carbon from a combination of epibionts, benthic algae and detritus derived from Codium.
108

CRETACEOUS CONFLUENCE IN THE COON CREEK FORMATION (MAASTRICHTIAN) OF MISSISSIPPI AND TENNESSEE, USA: TAPHONOMY AND SYSTEMATIC PALEONTOLOGY OF A DECAPOD KONSENTRAT-LAGERSTATTE

Kornecki, Krystyna Maria 31 October 2014 (has links)
No description available.
109

Evolution and function of cellulase genes in Australian freshwater crayfish

Crawford, Allison Clare January 2006 (has links)
The most abundant organic compound produced by plants is cellulose, however it has long been accepted that animals do not secrete the hydrolytic enzymes required for its degradation, but rely instead on cellulases produced by symbiotic microbes. The recent discovery of an endogenous cDNA transcript encoding a putative GHF9 endoglucanase in the parastacid crayfish Cherax quadricarinatus (Byrne et al., 1999) suggests that similar cellulase genes may have been inherited by a range of crustacean taxa. In this study, the evolutionary history of the C. quadricarinatus endoglucanase gene and the presence of additional GHF9 genes in other decapod species were investigated. The activity of endoglucanase and endoxylanase enzymes within several cultured decapod species were also compared. The evolutionary history of the C. quadricarinatus endoglucanase gene was assessed by comparing intron/exon structure with that of other invertebrate and plant GHF9 genes. The coding region of the gene was found to be interrupted by eleven introns ranging in size from 102-902 bp, the position of which was largely conserved in both termite and abalone GHF9 genes. These structural similarities suggest GHF9 genes in crustaceans and other invertebrate taxa share a common ancestry. In addition, two introns were observed to share similar positions in plant GHF9 genes, which indicates this enzyme class may have been present in ancient eukaryote organisms. The presence of GHF9 genes in C. quadricarinatus and various other decapod species was then explored via degenerate primer PCR. Two distinct GHF9 gene fragments were determined for C. quadricarinatus and several other Cherax and Euastacus parastacid freshwater crayfish species, and a single GHF9 gene fragment was also determined for the palaemonid freshwater prawn Macrobrachium lar. Phylogenetic analyses of these fragments confirmed the presence of two endoglucanase genes within the Parastacidae, termed EG-1 and EG-2. The duplication event that produced these two genes appears to have occurred prior to the evolution of freshwater crayfish. In addition, EG-2 genes appear to have duplicated more recently within the Cherax lineage. The presence of multiple GHF9 endoglucanase enzymes within the digestive tract of some decapod species may enable more efficient processing of cellulose substrates present in dietary plant material. Endoglucanase and endoxylanase enzyme activities were compared in several parastacid crayfish and penaeid prawn species using dye-linked substrates. Endoglucanase activity levels were higher in crayfish compared with prawn species, which corresponds with the known dietary preferences of these taxa. Endoglucanase temperature and pH profiles were found to be very similar for all species examined, with optimum activity occurring at 60°C and pH 5.0. These results suggest endoglucanase activity in penaeid prawns may also be derived from endogenous sources. Additional in vitro studies further demonstrated crayfish and prawn species liberate comparable amounts of glucose from carboxymethyl-cellulose, which indicates both taxa may utilise cellulose substrates as a source of energy. Endoxylanase temperature and pH profiles were also similar for all crayfish species examined, with optimal activity occurring at 50°C and pH 5.0. These results suggest xylanase activity in crayfish may originate from endogenous enzymes, although it is unclear whether this activity is derived from GHF9 enzymes or a different xylanase enzyme class. In contrast, no endoxylanase activity was detected in the three prawn species examined. Together, these findings suggest a wide range of decapod crustacean species may possess endogenous GHF9 endoglucanase genes and enzymes. Endoglucanases may be secreted by various decapod species in order to digest soluble or amorphous cellulose substrates present in consumed plant material. Further biochemical studies may confirm the presence and functional attributes of additional endoglucanase genes and enzymes in decapods, which may ultimately assist in the design of optimal plant based crustacean aquaculture feeds.
110

The role of the sandprawn, Callichirus kraussi, as an ecosystem engineer in a temporarily open/closed Eastern Cape estuary, South Africa

Njozela, Cuma January 2013 (has links)
The role of the sandprawn, Callichirus (=Callianassa) kraussi (Stebbing), as an ecosystem engineer was assessed in the lower reach of the temporarily open/closed Kasouga Estuary situated along the Eastern Cape coastline of southern Africa over the period April 2010 to June 2011. The study comprised two distinct components, a field study and a caging experiment. The field study assessed the correlation between sand prawn densities and selected physico-chemical (organic content of the sediment and bioturbation) and biological (microphytobenthic algal concentrations and macrobenthic abundance and biomass) variables in 50 quadrants in the lower reach of the estuary. Densities of the sand prawn within the quadrants ranged from 0 to 156 ind m⁻² (mean = 37 ind m⁻²). There were no significant correlations between the densities of the sandprawn and the estimates of the organic content of the sediment and the abundance and biomass of the macrofauna (P > 0.05 in all cases). Numerical analyses failed to identify any effect of the sandprawn density on the macrofaunal community structure. The rate of bioturbation was, however, strongly correlated to the sand prawn density. Similarly, the microphytobenthic alga concentrations were significantly negatively correlated to the sand prawn densities ((P < 0.05). The absence of any distinct impact of the sandprawn on the macrobenthic community structure appeared to be related to their low densities in the lower reach of the estuary during the study. To better understand the role of the sandprawn as an ecosystem engineer, a caging experiment was conducted using inclusion and exclusion treatments (n= 5 for each treatment). Densities of the sandprawn in the inclusion treatments (80 ind m⁻²) were in the range of the natural densities within the estuary. The experiment was conducted over a period of 18 weeks in the lower reach of the estuary during summer. The presence of the sandprawn, C kraussi, contributed to a significant decrease in the microphytobenthic algal concentrations and the abundance and biomass of the macrofauna (P < 0.05 in all cases). The decrease in the microphytobenthic algal concentrations in the presence of the sandprawn appeared to be related to the res-suspension of the sediments (bioturbation) generated by the burrowing and feeding activities of the sandprawn. The observed decrease in macrofaunal abundances and biomass in the inclusion treatments appeared to be mediated by both the decreased food availability (mainly the microphytobenthic algae) and the burial of organisms within the sediments. Numerical analysis indicated that the sandprawn did, however, not contribute to a change in the species composition of the macrofauna. Results of the current study indicate that C.kraussi plays an important role in structuring the invertebrate community and energy flow within temporarily/open closed Kasouga Estuary.

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