963 resultados para Species identification


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DNA Barcoding (Hebert et al. 2003) has the potential to revolutionize the process of identifying and cataloguing biodiversity; however, significant controversy surrounds some of the proposed applications. In the seven years since DNA barcoding was introduced, the Web of Science records more than 600 studies that have weighed the pros and cons of this procedure. Unfortunately, the scientific community has been unable to come to any consensus on what threshold to use to differentiate species or even whether the barcoding region provides enough information to serve as an accurate species identification tool. The purpose of my thesis is to analyze mitochondrial DNA (mtDNA) barcoding’s potential to identify known species and provide a well-resolved phylogeny for the New Zealand cicada genus Kikihia. In order to do this, I created a phylogenetic tree for species in the genus Kikihia based solely on the barcoding region and compared it to a phylogeny previously created by Marshall et al. (2008) that benefits from information from other mtDNA and nuclear genes as well as species-specific song data. I determined how well the barcoding region delimits species that have been recognized based on morphology and song. In addition, I looked at the effect of sampling on the success of barcoding studies. I analyzed subsets of a larger, more densely sampled dataset for the Kikihia Muta Group to determine which aspects of my sampling strategy led to the most accurate identifications. Since DNA barcoding would by definition have problems in diagnosing hybrid individuals, I studied two species (K. “murihikua” and K. angusta) that are known to hybridize. Individuals that were not obvious hybrids (determined by morphology) were selected for the case study. Phylogenetic analysis of the barcoding region revealed insights into the reasons these two species could not be successfully differentiated using barcoding alone.

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Las aguas residuales son potenciales portadoras de enteroparásitos patógenos para el hombre cuya dosis infectiva puede ser mínima y prolongado el tiempo de sobrevivencia de huevos y quistes en el ambiente. La reglamentación limita la presencia de huevos de helmintos y, hasta el año 2000, no proponía una técnica para su detección. Este trabajo se realizó para caracterizar parasitológicamente los efluentes procedentes de agroindustrias. La capacitación en la identificación microscópica demandó la confección de fichas que describen las características de huevos de helmintos. Se efectuaron ensayos con muestras de bodegas y aceiteras en los puntos detectados de contaminación. Los métodos fueron adaptados a las particularidades de los efluentes. Los resultados no señalaron presencia de helmintos; no obstante, se hallaron Cyclospora e Isospora, protozoarios que, por su alto poder infectivo, también constituyen un riesgo para el hombre. Sin embargo, no están contemplados por la legislación. Respecto a helmintos, es necesario un estudio comparativo de las técnicas de detección para efluentes agroindustriales, con el fin de establecer las que optimicen su recuperación. En cuanto a otras especies es preciso continuar investigando su presencia para evaluar la conveniencia de incorporarlas a la reglamentación.

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The samples were concentrated down to 50 cm**3 by slow decantation after storage for 20 days in a cool and dark place. The species identification was done under light microscope OLIMPUS-BS41 connected to a video-interactive image analysis system at magnification of the ocular 10X and objective - 40X. A Sedgwick-Rafter camera (1ml) was used for counting. 400 specimen were counted for each sample, while rare and large species were checked in the whole sample (Manual of phytoplankton, 2005). Species identification was mainly after Carmelo T. (1997) and Fukuyo, Y. (2000). Total phytoplankton abundance was calculated as sum of taxon-specific abundances. Total phytoplankton biomass was calculated as sum of taxon-specific biomasses. The cell biovolume was determined based on morpho-metric measurement of phytoplankton units and the corresponding geometric shapes as described in detail in (Edier, 1979).

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The dataset is composed of 57 samples from 15 stations. The phytoplankton samples were collected by 5l Niskin bottles attached to the CTD system. The sampling depths were selected according to the CTD profiles and the in situ fluorometer readings. The samples (50 ml sea water) were preserved with prefiltered (0.2 micron) glutardialdehyde solution (1.5 ml of commercial glutardialdehyde (25%)) into dark colored glass bottles. Preserved samples were poured into 10 or 25 ml settling chambers (Hydro-Bios) for cells to settle on the bottom over a day. Species identification and enumeration were done under an inverted microscope (Olympus IX71). At least 400 specimen were tried to be counted in each sample.

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The dataset is composed of 34 samples from 23 stations. The phytoplankton samples were collected by 5l Niskin bottles attached to the CTD system. The sampling depths were selected according to the CTD profiles and the in situ fluorometer readings. The samples (50 ml sea water) were preserved with prefiltered (0.2 micron) glutardialdehyde solution (1.5 ml of commercial glutardialdehyde (25%)) into dark colored glass bottles. Preserved samples were poured into 10 or 25 ml settling chambers (Hydro-Bios) for cells to settle on the bottom over a day. Species identification and enumeration were done under an inverted microscope (Olympus IX71). At least 400 specimen were tried to be counted in each sample.

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The dataset is composed of 22 samples from 14 stations. The phytoplankton samples were collected by 5l Niskin bottles attached to the CTD system. The sampling depths were selected according to the CTD profiles and the in situ fluorometer readings. The samples (50 ml sea water) were preserved with prefiltered (0.2 micron) glutardialdehyde solution (1.5 ml of commercial glutardialdehyde (25%)) into dark colored glass bottles. Preserved samples were poured into 10 or 25 ml settling chambers (Hydro-Bios) for cells to settle on the bottom over a day. Species identification and enumeration were done under an inverted microscope (Olympus IX71). At least 400 specimen were tried to be counted in each sample.

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The dataset is composed of 61 samples from 15 stations. The phytoplankton samples were collected by 5l Niskin bottles attached to the CTD system. The sampling depths were selected according to the CTD profile and the in situ fluorometer readings: surface, temperature, salinity and fluorescence gradients and 1 m above the bottom. At some stations phytoplankton net samples (20 µm mesh-size) were collected to assist species biodiversity examination. The samples (1l sea water) were preserved in 4% buffered to pH 8-8.2 with disodiumtetraborate formaldehyde solution and stored in plastic containers. On board at each station few live samples were qualitatively examined under microscope for preliminary analysis of taxonomic composition and dominant species. Taxon-specific phytoplankton abundance were concentrated down to 50 cm**3 by slow decantation after storage for 20 days in a cool and dark place. The species identification was done under light microscope OLIMPUS-BS41 connected to a video-interactive image analysis system at magnification of the ocular 10X and objective - 40X. A Sedgwick-Rafter camera (1ml) was used for counting. 400 specimen were counted for each sample, while rare and large species were checked in the whole sample (Manual of phytoplankton, 2005). Species identification was mainly after Carmelo T. (1997) and Fukuyo, Y. (2000). The cell biovolume of the taxon-specific phytoplankton biomass was determined based on morpho-metric measurement of phytoplankton units and the corresponding geometric shapes as described in detail in (Edier, 1979).

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The dataset is composed of 46 samples from 9 stations. The phytoplankton samples were collected by 5l Niskin bottles attached to the CTD system. The sampling depths were selected according to the CTD profiles and the in situ fluorometer readings. The samples (50 ml sea water) were preserved with prefiltered (0.2 micron) glutardialdehyde solution (1.5 ml of commercial glutardialdehyde (25%)) into dark colored glass bottles. Preserved samples were poured into 10 or 25 ml settling chambers (Hydro-Bios) for cells to settle on the bottom over a day. Species identification and enumeration were done under an inverted microscope (Olympus IX71). At least 400 specimen were tried to be counted in each sample.

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The dataset is composed of 48 samples from 17 stations. The phytoplankton samples were collected by 5l Niskin bottles attached to the CTD system. The sampling depths were selected according to the CTD profiles and the in situ fluorometer readings. The samples (50 ml sea water) were preserved with prefiltered (0.2 micron) glutardialdehyde solution (1.5 ml of commercial glutardialdehyde (25%)) into dark colored glass bottles. Preserved samples were poured into 10 or 25 ml settling chambers (Hydro-Bios) for cells to settle on the bottom over a day. Species identification and enumeration were done under an inverted microscope (Olympus IX71). At least 400 specimen were tried to be counted in each sample.

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The dataset is composed of 20 samples from 14 stations. The phytoplankton samples were collected by 5l Niskin bottles attached to the CTD system. The sampling depths were selected according to the CTD profiles and the in situ fluorometer readings. The samples (50 ml sea water) were preserved with prefiltered (0.2 micron) glutardialdehyde solution (1.5 ml of commercial glutardialdehyde (25%)) into dark colored glass bottles. Preserved samples were poured into 10 or 25 ml settling chambers (Hydro-Bios) for cells to settle on the bottom over a day. Species identification and enumeration were done under an inverted microscope (Olympus IX71). At least 400 specimen were tried to be counted in each sample.

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The dataset is composed of 41 samples from 10 stations. The phytoplankton samples were collected by 5l Niskin bottles attached to the CTD system. The sampling depths were selected according to the CTD profile and the in situ fluorometer readings: surface, temperature, salinity and fluorescence gradients and 1 m above the bottom. At some stations phytoplankton net samples (20 µm mesh-size) were collected to assist species biodiversity examination. The samples (1l sea water) were preserved in 4% buffered to pH 8-8.2 with disodiumtetraborate formaldehyde solution and stored in plastic containers. On board at each station few live samples were qualitatively examined under microscope for preliminary analysis of taxonomic composition and dominant species. The taxon-specific phytoplankton abundance samples were concentrated down to 50 cm**3 by slow decantation after storage for 20 days in a cool and dark place. The species identification was done under light microscope OLIMPUS-BS41 connected to a video-interactive image analysis system at magnification of the ocular 10X and objective - 40X. A Sedgwick-Rafter camera (1ml) was used for counting. 400 specimen were counted for each sample, while rare and large species were checked in the whole sample (Manual of phytoplankton, 2005). Species identification was mainly after Carmelo T. (1997) and Fukuyo, Y. (2000). Total phytoplankton abundance was calculated as sum of taxon-specific abundances. Total phytoplankton biomass was calculated as sum of taxon-specific biomasses. The cell biovolume was determined based on morpho-metric measurement of phytoplankton units and the corresponding geometric shapes as described in detail in (Edier, 1979).

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The samples were concentrated down to 50 cm**3 by slow decantation after storage for 20 days in a cool and dark place. The species identification was done under light microscope OLIMPUS-BS41 connected to a video-interactive image analysis system at magnification of the ocular 10X and objective - 40X. A Sedgwick-Rafter camera (1ml) was used for counting. 400 specimen were counted for each sample, while rare and large species were checked in the whole sample (Manual of phytoplankton, 2005). Species identification was mainly after Carmelo T. (1997) and Fukuyo, Y. (2000). Taxon-specific phytoplankton abundance and biomass were analysed by Moncheva S., B. Parr, 2005. Manual for Phytoplankton Sampling and Analysis in the Black Sea. The cell biovolume was determined based on morpho-metric measurement of phytoplankton units and the corresponding geometric shapes as described in detail in (Edier, 1979).

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The "MARECHIARA-phytoplankton" dataset contains phytoplankton data collected in the ongoing time-series at Stn MC ( 40°48.5' N, 14°15' E) in the Gulf of Naples. This dataset spans over the period 1984-2006 and contains data of phytoplankton species composition and abundance. Phytoplankton sampling was regularly conducted from January 1984 till July 1991 and in 1995-2006. Sampling was interrupted from August 1991 till January 1995. The sampling frequency was fortnightly till 1991 and weekly since 1995. Phytoplankton samples were collected at 0.5 m depth using Niskin bottles and immediately fixed with formaldehyde (0.8-1.6% final concentration) for species identification and counts.