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dc.contributor.advisorSantos-Flores, Carlos J.
dc.contributor.authorFlores-Nieves, Chris Z.
dc.description.abstractInvasive species are a major focus within conservation biology. The widely introduced cane toad, Rhinella marina, has gained particular interest in studies of effects of invasive species on native communities. In this study I examined the effects of invasive cane toad larvae on the growth, development and survival of a Puerto Rican native species, the white-lipped frog, Leptodactylus albilabris, when tadpoles were reared with different food levels. I conducted two experiments: (1) a food calibration experiment to determine low and high food concentrations adequate for larvae growth and survival, and (2) a competition experiment with varying species rations and food availability. In the food calibration experiment, lower food levels reduced survival and increased larval period for both species. Contrary to the expected results in the competition experiment, the presence of R. marina had no negative effects on L. albilabris development. Rather, the opposite outcome was observed; larvae of R. marina experienced severe reduction in growth and survival when in the presence of L. albilabris, particularly in the high food level treatments. Significant effects of the presence of L. albilabris on R. marina development were observed as early as the first two weeks, and continued on to metamorphosis. Adaptations to life on ephemeral habitats such as larger body size, higher activity levels and reduced larval period, combined with high food levels, may have provided L. albilabris with a competitive advantage over R. marina. Further studies are needed to determine if these interactions produce similar results under natural conditions.
dc.description.abstractLas especies invasivas son el enfoque de la biología de la conservación. El sapo de la caña de azúcar, Rhinella marina, ha ganado particular interés en estudios para demostrar los efectos de especies invasivas en comunidades de especies nativas. En este estudio se examinaron los efectos de las larvas del sapo de la caña en el crecimiento, desarrollo y sobrevivencia de una especie nativa puertorriqueña, la ranita de labio blanco, Leptodactylus albilabris, bajo diferentes niveles de alimento. Se utilizaron dos procesos experimentales: (1) experimento de calibración para determinar niveles adecuados (bajo y alto) de comida para crecimiento y sobrevivencia de los renacuajos y (2) experimento de competencia entre ambas especies bajo dos niveles de comida (alto y bajo). Los bajos niveles de comida redujeron la sobrevivencia y aumentaron el periodo larval de ambas especies. Contrario a los resultados esperados para el experimento de competencia, la presencia de R. marina no tuvo efectos negativos en el desarrollo de L. albilabris. Se observó la situación inversa, donde las larvas de R. marina experimentaron reducciones severas en crecimiento y sobrevivencia cuando se encontraban juntas con L. albilabris, particularmente con niveles altos de comida. Se observaron efectos significativos de la presencia de L. albilabris en el desarrollo de R. marina desde las primeras dos semanas de desarrollo, los cuales continuaron hasta la metamorfosis. Las adaptaciones que presenta L. albilabris para vivir en ambientes temporeros como mayor tamaño, alto nivel de actividad y periodos larvales reducidos, combinado con altos niveles de alimento, pudieron haber dado la ventaja competitiva a esta especie sobre R. marina. Se necesitan estudios futuros para ver si estas interacciones producen resultados similares bajo condiciones naturales.
dc.subjectInvasive speciesen_US
dc.subjectRhinella marinaen_US
dc.subjectLeptodactylus albilabrisen_US
dc.subjectR. marinaen_US
dc.subjectL. albilabrisen_US
dc.subject.lcshIntroduced organisms--Puerto Ricoen_US
dc.subject.lcshBufo marinus--Puerto Ricoen_US
dc.titleEffects of food concentration in the competition between larvae of the introduced cane toad (Rhinella marina) and the native white-lipped frog (Leptodactylus albilabris)en_US
dc.rights.licenseAll rights reserveden_US
dc.rights.holder(c) 2012 Chris Zuleira Flores-Nievesen_US
dc.contributor.committeeLogue, David
dc.contributor.committeeBorges Delgado, Sonia
dc.contributor.representativeSantiago Román, Aidsa I.
dc.contributor.collegeCollege of Arts and Sciences - Sciencesen_US
dc.contributor.departmentDepartment of Biologyen_US

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