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Full-Text Articles in Life Sciences

Seagrass–Pathogen Interactions: ‘Pseudo-Induction’ Of Turtlegrass Phenolics Near Wasting Disease Lesions, Latina Steele, Melanie Caldwell, Anne Boettcher, Tom Arnold Nov 2005

Seagrass–Pathogen Interactions: ‘Pseudo-Induction’ Of Turtlegrass Phenolics Near Wasting Disease Lesions, Latina Steele, Melanie Caldwell, Anne Boettcher, Tom Arnold

Biology Faculty Publications

Marine protists of the genus Labyrinthula cause the seagrass wasting disease, which is associated with regional die-offs of eelgrass Zostera marina and also infects turtlegrass Thalassia testudinum . The ability of seagrasses to resist pathogen attack is determined by multiple factors, which are poorly understood. One factor hypothesized to influence seagrass disease resistance is the presence of (poly)phenolic natural products such as caffeic acid, which inhibits the growth of L. zosterae in in vitro laboratory bioassays. This hypothesis has been supported by reports of pathogen-induced phenolic accumulations in eelgrass Z. marina. To test the response of T. testudinum to …


Redescripción De La Morfología Larval Externa De Dos Especies Del Grupo De Leptodactylus Fuscus (Anura, Leptodactylidae), José A. Langone, Rafael O. De Sá Oct 2005

Redescripción De La Morfología Larval Externa De Dos Especies Del Grupo De Leptodactylus Fuscus (Anura, Leptodactylidae), José A. Langone, Rafael O. De Sá

Biology Faculty Publications

Re-description of the larval external morphology of two species of the Leptodactylus fuscus group (Anura, Leptodactylidae). The larvae of Leptodactylus gracilis (D’Orbigny y Bibron, 1840) and L. mystacinus Bumeister, 1861 are re-described and compared with previous descriptions noting intraspecific variation in oral disc characteristics (arrangement of papillae and rows of cornified teeth). The external morphological analysis of larvae of the Leptodactylus fuscus group suggest that the lack of comparable descriptions among species, as well as the lack of analyses of their intraspecific variation, limits the use of larval characteristics for diagnostic purposes.


A Phylogenetic Analysis Of Vanzolinius Heyer, 1974 (Amphibia, Anura, Leptodactylidae): Taxonomic And Life History Implications, Rafael O. De Sá, W. Ronald Heyer, Arley Camargo Oct 2005

A Phylogenetic Analysis Of Vanzolinius Heyer, 1974 (Amphibia, Anura, Leptodactylidae): Taxonomic And Life History Implications, Rafael O. De Sá, W. Ronald Heyer, Arley Camargo

Biology Faculty Publications

The validity of the monotypic leptodactylid frog genus Vanzolinius Heyer, 1974 has been questioned recently. We explore the relationship of Vanzolinius discodactylus within the cluster of closely related genera Adenomera, Leptodacylus, and Lithodytes with both morphological and molecular data sets. Morphological and combined morphological and molecular data were analyzed using maximum parsimony; molecular data sets were analyzed with maximum likelihood methods. The resultant relationships are unambiguous in Vanzolinius being imbedded within Leptodactylus. In order to maintain Leptodactylus as a monophyletic genus, Vanzolinius is placed in the synonymy of Leptodactylus Fitzinger, 1826. The implications of relationships analyzed in …


"Sibling Species, Advertisement Calls, And Reproductive Isolation In Frogs Of The Leptodactylus Pentadactylus Species Cluster (Amphibia, Leptodactylidae), W. Ronald Heyer, Rafael O. De Sá, A. Rettig Aug 2005

"Sibling Species, Advertisement Calls, And Reproductive Isolation In Frogs Of The Leptodactylus Pentadactylus Species Cluster (Amphibia, Leptodactylidae), W. Ronald Heyer, Rafael O. De Sá, A. Rettig

Biology Faculty Publications

A recent re-evaluation of morphological and advertisement call variation in the large species of frogs of the Leptodactylus pentadactylus cluster discovered more examples of sibling species as defined by Ernst Mayr in his influential book Animal Species and Evolution. All previously documented instances of sibling species in frogs demonstrated advertisement call differentiation consistent with the calls serving as pre-mating isolating mechanisms. However, we find one instance of two species with nondistinguishable adult morphologies as well as nondistinguishable advertisement calls. Presumably, the new instances of sibling species reflect retention of ancestral adult morphologies and advertisement calls. Larval and habitat differentiation appear …


Judicious Use Of Multiple Hypothesis Tests, Paul J. Roback, Robert A. Askins Feb 2005

Judicious Use Of Multiple Hypothesis Tests, Paul J. Roback, Robert A. Askins

Biology Faculty Publications

When analyzing a table of statistical results, one must first decide whether adjustment of significance levels is appropriate. If the main goal is hypothesis generation or initial screening for potential conservation problems, then it may be appropriate to use the standard comparisonwise significance level to avoid Type 2 errors (not detecting real differences or trends). If, however, the main goal is rigorous testing of a hypothesis, then an adjustment for multiple tests is needed. To control the familywise Type 1 error rate (the probability of rejecting at least one true null hypothesis), sequential modifications of the standard Bonferroni Method, such …


Common Names For The Frog Genus Leptodactylus (Amphibia, Anura, Leptodactylidae), Ulisses Caramaschi, Rafael O. De Sá, W. Ronald Heyer Jan 2005

Common Names For The Frog Genus Leptodactylus (Amphibia, Anura, Leptodactylidae), Ulisses Caramaschi, Rafael O. De Sá, W. Ronald Heyer

Biology Faculty Publications

Most species of the frog genus Leptodactylus lack common names. Common names are those names used by different human cultures and societies for the species of animals and plants where humans and biota reside together. Often times common names are lacking for Neotropical frogs or are broad in scope. For example, indigenous people may have a single name for frogs that occur on the ground and another name for frogs that occur in shrubs and trees, even though there are many species of ground frogs called by the same name as well as for the tree frogs. Sometimes colonists have …


Are Leptodactylus Didymus And L. Mystaceus Phylogenetically Sibling Species (Amphibia, Anura, Leptodactylidae)?, Rafael O. De Sá, W. R. Heyer, Arley Camargo Jan 2005

Are Leptodactylus Didymus And L. Mystaceus Phylogenetically Sibling Species (Amphibia, Anura, Leptodactylidae)?, Rafael O. De Sá, W. R. Heyer, Arley Camargo

Biology Faculty Publications

The Leptodactylus fuscus species group consists of 25 currently recognized species; within this species group and distributed throughout the Amazon Basin, Atlantic Forests, Gran Chaco, and cerrados is the L. mystaceus species complex. This species complex consists of L. didymus, L. elenae, L. mystaceus, L. notoaktites, and L. spixi. Adult morphologies have been used to distinguish these species from each other except for L. didymus and L. mystaceus (Heyer, 1978; Heyer et al., 1996). Leptodactylus didymus and L. mystaceus are morphologically indistinguishable; the species are recognizable only by the characteristics of their advertisement calls: non-pulsed in L. didymus and pulsed …


Crisis Global De Biodiversidad: Importancia De La Diversidad Genética Y La Extinción De Anfibios, Rafael O. De Sá Jan 2005

Crisis Global De Biodiversidad: Importancia De La Diversidad Genética Y La Extinción De Anfibios, Rafael O. De Sá

Biology Faculty Publications

El mundo enfrenta, por primera vez desde el comienzo de la civilización, el declive y la extinción de una clase de vertebrados, los anfibios. Esta extinción aparenta ser un evento global y de la magnitud que llevó a la desaparición de los dinosaurios. Muchas son las posibles causas de esta extinción y el efecto combinado de estos factores agravan la situación. La pérdida de ambientes naturales permanece como el factor más crítico en el declive de anfibios, pero enfermedades infecciosas emergentes parecen ser responsables de mortalidades masivas en décadas recientes. El declive y extinción de anfibios representa una llamada urgente …


On The Enigmatic Distribution Of The Honduran Endemic Leptodactylus Silvanimbus (Amphibia: Anura: Lep Todactylidae), W. Ronald Heyer, Rafael O. De Sá, Sarah Muller Jan 2005

On The Enigmatic Distribution Of The Honduran Endemic Leptodactylus Silvanimbus (Amphibia: Anura: Lep Todactylidae), W. Ronald Heyer, Rafael O. De Sá, Sarah Muller

Biology Faculty Publications

Most species of the frog genus Leptodactylus occur in South America, and all authors who have treated the zoogeography of the genus have concluded that it originated somewhere in South America (e.g., Savage 1982). Savage (1982,518) summarized the historical herpetofaunal units of the Neotropics as follows: "All evidence points to an ancient contiguity and essential similarity of a generalized tropical herpetofauna that ranged over tropical North, Middle, and most of South America in Cretaceous-Paleocene times. Descendents of this fauna are represented today by the South and Middle American tracks (Elements). To the north of this fauna ranged a subtropical-temperate Laurasian …