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dc.contributor.advisorSchizas, Nikolaos V.
dc.contributor.authorTorres-Pratts, Hernán
dc.date.accessioned2018-12-06T14:44:30Z
dc.date.available2018-12-06T14:44:30Z
dc.date.issued2009-12
dc.identifier.urihttps://hdl.handle.net/20.500.11801/1599
dc.description.abstractNatural populations of many marine invertebrates are under pressure by fisheries due to the increasing demand and unit prices leading to overexploitation. I examined the genetic variation of two marine invertebrates: the corallimorpharian Ricordea florida and the emerald crab Mithraculus sculptus both of which are heavily traded by the marine aquarium industry. A third species studied, the commensal barnacle Chelonibia caretta, was not under direct fishing pressure, but its host is an endangered species, the hawksbill sea turtle (Eretmochelys imbricata). Using direct sequencing of mitochondrial genes (COI and 16S) and the nuclear the ITS region (ITS1, 5.8S, and ITS2), the phylogeography and genetic population structure of these invertebrates were characterized. The genetic diversity in C. caretta was low compared to published sequences from populations of barnacles attached to fixed substrata. However, genetic diversity values from C. caretta were comparable to those reported from C. testudinaria, an epibiont barnacle on loggerhead turtles. Analysis of molecular variance and phylogenetic analysis of the sampled turtle epibionts indicated that they are genetically homogeneous, irrespective of the host or host gender. In contrast, the phylogeography of the ITS region of the coral R. florida uncovered two partial sympatric genetic lineages. These lineages showed two highly supported monophyletic groups when they were compared phylogenetically against published nuclear ribosomal sequences of other genera of Corallimorpharia (Actinodiscus, Amplexidiscus, Corynactis, and Rhodactis). Similarly to R. florida, the phylogeographic analysis of M. sculptus based on 16S revealed two distinct lineages distributed throughout the sampled region. The analysis of molecular variance and the phylogeography of the sampled populations of M. sculptus reflected that most of the specimens within each lilneage were collected from demographically open populations within the western Caribbean. In general, the three species studied are consistent with the prediction that higher rates of dispersal reduce population divergence and estimates of nucleotide diversity. As in previous studies, the absence of genetic differentiation between geographical distant populations of these species suggests high connectivity between all sampled areas. Additionally, the presence of cryptic lineages confirms concerns regarding that biodiversity can be vastly understudied for marine environment.en_US
dc.description.abstractLas poblaciones naturales de muchos invertebrados están bajo presión por las pesquerías debido a su creciente demanda y valor comercial, que conducen a su sobreexplotación. Yo examiné la variación genética de dos especies de invertebrados marinos: el corallimorfario Ricorea florida y el cangrejo esmeralda Mithraculus sculptus, ambos cosechados extensamente para la industria de acuarios marinos. Una tercera especie fue estudiada, la bayoca comensalista Chelonibia caretta, la cual no está bajo presión directa de la pesquería, pero su hospedero, el carey de concha (Eretmochelys imbricata), es una especie de tortuga marina amenazada. Utilizando amplificaciones directas de genes mitocondriales (COI y 16S) y nucleares (ITS1, 5.8S y ITS2) se caracterizó la filogeografía y estructura genética poblacional de estos invertebrados. La diversidad genética de Chelonibia caretta fue baja al compararla con secuencias publicadas de otras especies de bayocas sobre substratos fijos. Sin embargo, los valores de la variabilidad genética para C. caretta son comparables con aquellos publicados para C. testudinaria, bayoca epibionte de la tortuga marina cabezona. Análisis de variación molecular y análisis filogenético de los epibiontes muestreados de la tortuga indicaron que éstos son genéticamente homogéneos, independientemente del hospedero o del género del hospedero. En contraste, los análisis de la región del ITS de R. florida revelaron dos linajes genéticos parcialmente solapados. Estos linajes fueron comparados filogenéticamente contra secuencias ribosomales nucleares publicadas de otros géneros de Corallimorpharia (Actinodiscus, Amplexidiscus, Corynactis y Rhodactis) y cada linaje formó un grupo monofilético altamente apoyado. Al igual que para R. florida, los análisis filogenéticos del 16S de Mithraculus sculptus, revelaron dos linajes distribuidos a través de la región muestreada. Los análisis de varianza molecular y la filogeografia de las poblaciones muestreadas de M. sculptus reflejaron que la mayor parte de los especímenes, dentro de cada linage, fueron colectados de poblaciones demográficamente abiertas dentro del Caribe occidental. En general, las tres especies estudiadas son consistentes con la predicción de que si los índices de dispersión son altos disminuyen la divergencia y los estimados de diversidad de nucleótidos. Como en estudios previos, la ausencia de la diferenciación genética entre poblaciones geográficamente distantes de estas especies sugiere una alta conectividad entre las áreas muestreadas. En adición, la presencia de linajes crípticos confirma la preocupación de que la biodiversidad está sub-estimada en los ambientes marinos.en_US
dc.description.sponsorshipDepartment of Energy (DOE); Alliance for Graduate Education and the Professoriate (AGEP); NSF-EPSCoR programs; Globe Program; Biology Department; Sequencing Facility at the University of Puerto Rico, Río Piedras Campusen_US
dc.language.isoenen_US
dc.subjectMarine invertebrate populations - Phylogeographyen_US
dc.subjectMarine invertebrate populations - Genetic sequencingen_US
dc.subjectCorallimorpharian Ricordea florida - Genetic population structureen_US
dc.subjectEmerald crab Mithraculus sculptus - Genetic population structureen_US
dc.subject.lcshMarine invertebrates--Geneticsen_US
dc.titleGenetic diversity and population structure of Caribbean marine invertebratesen_US
dc.typeDissertationen_US
dc.rights.licenseAll rights reserveden_US
dc.rights.holder(c) 2009 Hernán Torres-Prattsen_US
dc.contributor.committeeOtero Morales, Ernesto
dc.contributor.committeeYoshioka, Paul
dc.contributor.committeeWilliams, Ernest H.
dc.contributor.committeeMontalvo Rodríguez, Rafael
dc.contributor.committeeCraig, Matthew T.
dc.contributor.committeeAponte, Nilda E.
dc.contributor.representativeMuñoz, Carlos Alberto
thesis.degree.levelPh.D.en_US
thesis.degree.disciplineMarine Sciencesen_US
dc.contributor.collegeCollege of Arts and Sciences - Sciencesen_US
dc.contributor.departmentDepartment of Marine Sciencesen_US
dc.description.graduationSemesterFallen_US
dc.description.graduationYear2009en_US


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