5,471 research outputs found
Activities of trading vessels and supplying fishers in the Grenadine Islands, Lesser Antilles
Molecular Phylogenetics of Perciform Fishes Using the Nuclear Recombination Activating Gene 1
The order Perciformes contains one-third of all extant fishes in twenty different suborders and over 10,000 species. Few systematic investigations have been performed on this large group of fishes at the suborder level and their evolutionary history is widely recognized as problematic. This dissertation presents three studies: a molecular phylogenetic analysis of the putative suborders of the order Perciformes, an analysis of interrelationships of the families of the perciform suborder Percoidei, and a multi-gene investigation of the percoid superfamily Sparoidea.
The taxa sampled in this dissertation represent one of the most inclusive molecular datasets, to date, testing the monophyly of the Perciformes and relationships of its suborders, including the Percoidei. Analyses are performed using a 1425-1431 base fragment of exon three of the single copy, nuclear recombination activating gene 1 (RAG1). Results of these tests reject the monophyly of the Perciformes and of its largest suborder, the Percoidei. However, this study does support some previous relationships at the suborder and family level for these groups and also presents novel interpretations of many groups. A lack of nodal support is seen for mid-level clades in these analyses. Genetic bias, such as high GC content and low effective number of codons, in some taxa, is hypothesized to be one of the causes for some of the unexpected relationships found in this work.
A multi-gene approach was taken to test the monophyly of the superfamily Sparoidea and its families. Analyses of RAG1, cytochrome b (cytB), and combined RAG1 + cytB datasets reject a monophyletic Sparoidea but find the Nemipteridae, Sparidae plus Centracanthidae, and Lethrinidae to be individually monophyletic. The one exception to this is in the cytB maximum likelihood phylogeny, which fails to resolve a monophyletic Lethrinidae.
The phylogenetic hypotheses discussed in this dissertation are an important step toward an understanding of perciform, percoid, and sparoid relationships and deserve further testing. The high level of taxon sampling presented here should be replicated and expanded using other molecular markers to help resolve the bush at the top of the teleostean tree
Caribbean coastal resources co-management -- part 1; Recursos costeros del Caribe co-gerencia de los recursos: parte 1
Report of the workshop on assessing governance in the Bay of Bengal Large Marine Ecosystem, Bangkok, Thailand, 28-30 October, 2014
The objective of the workshop was to begin a structured discussion on regional governance in the BOBLME, drawing on lessons from a region with similar issues, the Carribean. Conclusions were made about principles, regional governance arrangements, national-regional interface and national science-policy interfaces. Future work was also planned
Management of tunas and tuna-like species in CARICOM countries: recent trends urge a new perspective and approach
The role of attention in eye-movement awareness
People are unable to accurately report on their own eye movements most of the time. Can this be explained as a lack of attention to the objects we fixate? Here, we elicited eye-movement errors using the classic oculomotor capture paradigm, in which people tend to look at sudden onsets even when they are irrelevant. In the first experiment, participants were able to report their own errors on about a quarter of the trials on which they occurred. The aim of the second experiment was to assess what differentiates errors that are detected from those that are not. Specifically, we estimated the relative influence of two possible factors: how long the onset distractor was fixated (dwell time), and a measure of how much attention was allocated to the onset distractor. Longer dwell times were associated with awareness of the error, but the measure of attention was not. The effect of the distractor identity on target discrimination reaction time was similar whether or not the participant was aware they had fixated the distractor. The results suggest that both attentional and oculomotor capture can occur in the absence of awareness, and have important implications for our understanding of the relationship between attention, eye movements, and awareness
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