Life Sciences Commons^™

Multiple Connections Between Amazonia And Atlantic Forest Shaped The T Phylogenetic And Morphological Diversity Of Chiasmocleis Mehely, 1904 (Anura: Microhylidae: Gastrophryninae), Rafael O. De Sá, João Filipe Riva Tonini, Hannah Van Huss, Alex Long, Travis Cuddy, Mauricio C. Forlani, Pedro L.V. Peloso, Hussam Zaher, Célio F.B. Haddad

Biology Faculty Publications

Chiasmocleis is the most species-rich genus of Neotropical microhylids. Herein, we provide the first comprehensive multilocus phylogeny for the genus, including all but 3 of the 34 recognized species and multiple individuals per species. We discuss cryptic speciation, species discovery, patterns of morphological evolution, and provide a historical biogeographic analysis to account for the current distribution of the genus. Diversification of Chiasmocleis from other New World microhylids began during the Eocene, app. 40 mya, in forested areas, and current diversity seems to be a product of recurrent connections between the Atlantic Forest and Amazonia. Small-sized species evolved independently three times …

A Global Community Effort To Decipher The Unique Biology Of Annual Killifish, Nibia Berois, Graciela Garcia, Rafael O. De Sá

Biology Faculty Publications

Over the past 50 years, annual killifishes arose as alternative model organisms for studies of vertebrate biology. The annual fish offers exceptional advantages for studies of genetics, genomics, developmental biology, population dynamics, ecology, biogeography, and evolution. They inhabit extremely variable freshwater environments in Africa and South America, have a short lifespan and a set of unique and fascinating developmental characteristics. Embryos survive within the dry substrate during the dry season, whereas the adult population dies. Thus, the survival of the populations is entirely dependent on the buried embryos that hatch the next rainy season. Although Old and New World species …

Molecular And Morphological Data Reveal Three New Cryptic Species Of Chiasmocleis (Mehely 1904) (Anura, Microhylidae) Endemic To The Atlantic Forest, Brazil, Mauricio C. Forlani, João F. R. Tonini, Carlos A. G. Cruz, Hussam Zaher, Rafael O. De Sá

Biology Faculty Publications

Three new cryptic species of Chiasmocleis from the Atlantic Forest of Brazil are described. Two of these species occur in the northeastern states of Sergipe and Bahia, whereas the third species is found in the southeastern state of São Paulo. The new species can be distinguished from other congeneric species by the molecular data, as evidenced in the phylogeny, and by a combination of morphological characters including: size, foot webbing, dermal spines, and coloration patterns. Chiasmocleis species differ in osteological traits, therefore we also provide an osteological description of each new species and comparisons with data reported for other species …

The Hidden History Of Humming Frogs, Rafael O. De Sá

Biology Faculty Publications

In the depths of Brazil’s Atlantic Forest, researchers are battling to identify species before they are lost for good. Dr Rafael O de Sá, Professor of Biology at the University of Richmond, Virginia, USA, specialises in a group known as the ‘narrow-mouthed frogs’ and has already found four species new to science.

High Genetic Diversity But Low Population Structure In The Frog Pseudopaludicola Falcipes (Hensel, 1867) (Amphibia, Anura) From The Pampas Of South America, José A. Langone, Arley Camargo, Rafael O. De Sá

Biology Faculty Publications

Relative to South America’s ecoregions, the temperate grasslands of the Pampas have been poorly studied from a phylogeographic perspective. Based on an intermediate biogeographic setting between subtropical forest (Atlantic Forest) and arid ecosystems (Chaco and Patagonia), Pampean species are expected to show unstable demographic histories due to the Quaternary climatic oscillations. Herein, we investigate the phylogenetic relatedness and phylogeographic history of Pseudopaludicola falcipes, a small and common frog that is widely distributed across the Pampean grasslands. First, we use molecular data to assess if P. falcipes represents a single or multiple, separately evolving cryptic lineages. Because P. falcipes is …

Persistence And Stability Of Eastern Afromontane Forests: Evidence From Brevicipitid Frogs, Simon P. Loader, F. Sara Ceccarelli, Michele Menegon, Kim M. Howell, Roman Kassahun, Abebe A. Mengistu, Samy A. Saber, Fikirte Gebresenbet, Rafael O. De Sá, Et Al.

Biology Faculty Publications

Aim: The persistence and stability of habitats through time are considered predictors of high levels of biodiversity in some environments. Long-term habitat persistence and stability may explain the species-rich, endemic forest fauna and flora of the Eastern Afromontane Biodiversity Region (EABR). Using comple- mentary phylogenetic and biogeographical approaches, we examine evolution- ary patterns in EAR brevicipitid frogs. Using these data, we test whether brevicipitid history reflects patterns of long-term forest persistence and/or sta bility across the EABR.

Location: East Africa.

Methods: A dated phylogeny for brevicipitids was constructed using two nuclear and three mitochondrial markers. Alternative diversification modes were used …

A Threat To New Zealand's Tuatara Heats Up, Kristine L. Grayson, Nicola J. Mitchell, Nicola J. Nelson

Biology Faculty Publications

No matter how many times we head to one of New Zealand's offshore islands, the feelings are always a mix of sheer awe at the beauty and biodiversity preserved in these special refuges and lingering nerves. Did we remember all the gear? Do we have enough food and water in case we get stuck? Can the helicopter land on the side of a cliff in these winds? These epic journeys are in pursuit of a lone remnant of the reptile evolutionary tree, with a unique ecology that has big implications under climate change.

Sex Ratio Bias And Extinction Risk In An Isolated Population Of Tuatara (Sphenodon Punctatus), Kristine L. Grayson, Nicola J. Mitchell, Joanne M. Monks, Susan N. Keall, Joanna N. Wilson, Nicola J. Nelson

Biology Faculty Publications

Understanding the mechanisms underlying population declines is critical for preventing the extinction of endangered populations. Positive feedbacks can hasten the process of collapse and create an ‘extinction vortex,’ particularly in small, isolated populations. We provide a case study of a male-biased sex ratio creating the conditions for extinction in a natural population of tuatara (Sphenodon punctatus) on North Brother Island in the Cook Strait of New Zealand. We combine data from long term mark-recapture surveys, updated model estimates of hatchling sex ratio, and population viability modeling to measure the impacts of sex ratio skew. Results from the mark-recapture …

Species Boundaries And Biogeography Of East African Torrent Frogs Of The Genus Petropedetes (Amphibia: Anura: Petropeditidae), Simon P. Loader, F. Sara Ceccarelli, Mark Wilkinson, Michele Menegon, Jean Mariaux, Rafael O. De Sá, Et Al.

Biology Faculty Publications

Based on morphology there are currently three described East African species of torrent frogs belonging to the tropical African genus Petropedetes (P. dutoiti, P. martiennseni and P. yakusini). Taxonomic uncertainties are evident within this group: a putative new species reported from the Nguru Mountains and the species P. yakusini have a fragmented distribution across the Southern Tanzanian highlands. We conducted a molecular systematic study, sampling populations of East African petropedetids occurring in the mountains of Tanzania (P. martiennseni and P. yakusini), to investigate species boundaries and biogeography. Data provide evidence for the recognition of …

Soil Nematodes And Their Prokaryotic Prey Along An Elevation Gradient In The Mojave Desert (Death Valley National Park, California, Usa), Amy M. Treonis, Kelsey Sutton, Brendan Kavanaugh, Archana Narla, Timothy Mcllarky, Jasmine Felder, Cecilia O'Leary, Megan Riley, Alyxandr Pikus, Sarah Thomas

Biology Faculty Publications

We characterized soil communities in the Mojave Desert across an elevation gradient. Our goal was to test the hypothesis that as soil quality improved with increasing elevation (due to increased productivity), the diversity of soil prokaryotes and nematodes would also increase. Soil organic matter and soil moisture content increased with elevation as predicted. Soil salinity did not correlate to elevation, but was highest at a mid-gradient, alluvial site. Soil nematode density, community trophic structure, and diversity did not show patterns related to elevation. Similar results were obtained for diversity of bacteria and archaea. Relationships between soil properties, nematode communities, and …

Survival, Breeding Frequency, And Migratory Orientation In The Jefferson Salamander, Ambystoma Jeffersonianum, Stephen P. De Lisle, Kristine L. Grayson

Biology Faculty Publications

Accurate estimates of demographic parameters, such as survival and breeding frequency, are necessary for the conservation and management of animal populations. Additionally, life-history data are required for gaining an empirical understanding of the ecology of natural populations. We monitored a population of Jefferson Salamanders (Ambystoma jeffersonianum) breeding in a permanent mountain-top pond at the southern limit of this species’ geographic range in Virginia over four years. We used closed multistate mark-recapture models with Pollock's robust design to estimate the demographic parameters of this population. Additionally, we used point-of-capture data to compare the orientation of migrations into and out …

Spots Of Adult Male Red-Spotted Newts Are Redder And Brighter Than In Females: Evidence For A Role In Mate Selection?, Andrew K. Davis, Kristine L. Grayson

Biology Faculty Publications

As aquatic adults, eastern red-spotted newts (Notophthalmus v. viridescens) are generally green with two rows of dorsal spots, which vary in number between individuals and range in colour from orange to red. The function of these spots is unknown, but it is possible that they serve as sexual ornamentations and we examined this hypothesis by testing for sexual dimorphism in spot characteristics. We used an image analysis approach that has been used previously with this and other amphibian species to compare the number, size and colour – redness (hue score) and brightness – of spots in 100 male …

What Do Students Have To Say About Ecology And Evolution? Using Podcasting To Apply Integrative Biology Themes Across The Tree Of Life, Amy M. Treonis, Malcolm Hill, Theresa Dolson, Sue Mcginnis, Elizabeth Miles

Biology Faculty Publications

We describe a versatile podcasting assignment that requires students to (i) review primary and secondary literature relating to an assigned organism with the goal of identifying the main features of its ecology and evolution, (ii) prepare an enhanced podcast about their organism, and (iii) critique peer podcasts. The goal of this assignment is for each student to gain a fuller appreciation for and understanding of biological diversity. This assignment will enhance students' research, technology, and communication skills while reinforcing the main themes of integrative biology.

Is The Amphibian Tree Of Life Really Fatally Flawed?, Darrel R. Frost, Taran Grant, Julian Faivovich, Raoul H. Bain, Alexander Haas, Celio F.B. Haddad, Rafael O. De Sá, Et Al.

Biology Faculty Publications

Wiens (2007, Q. Rev. Biol. 82, 55–56) recently published a severe critique of Frost et al.'s (2006, Bull. Am. Mus. Nat. Hist. 297, 1–370) monographic study of amphibian systematics, concluding that it is “a disaster” and recommending that readers “simply ignore this study”. Beyond the hyperbole, Wiens raised four general objections that he regarded as “fatal flaws”: (1) the sampling design was insufficient for the generic changes made and taxonomic changes were made without including all type species; (2) the nuclear gene most commonly used in amphibian phylogenetics, RAG-1, was not included, nor were the morphological characters that had justified …

Description Of The Tadpole Of Leptodactylus Pustulatus Peters, 1870 (Anura: Leptodactylidae), Rafael O. De Sá, Reuber Brandão, Lorena Dall'ara Guimarães

Biology Faculty Publications

The external morphology and oral disc of the tadpole of Leptodactylus pustulatus Peters, 1870, are described and illustrated for Gosner stage 39. The internal oral anatomy was analyzed with SEM at Gosner stage 36 whereas chondrocranial anatomy is reported for Gosner stage 35. The overall characteristics do not depart from those known for the genus Leptodactylus and they particularly agree for those of the melanonotus species group. The labial tooth row formula is 2(2)/3. Observations are presented that suggest that L. pustulatus engages in larval parental care.

Resumo

São descritas a morfologia externa e o disco oral do girino de …

Sex Differentiation Pattern In The Annual Fish Austrolebias Charrua (Cyprinodontiformes: Rivulidae), M. J. Arezo, S. D. Alessandro, N. Papa, Rafael O. De Sá, N. Berois

Biology Faculty Publications

Sex differentiation process, determination of sexual strategy, and gametogenesis of the annual fish Austrolebias charrua are established. Evidence of histological sex differentiation in an antero-posterior gradient was observed in pre-hatching stages. Sexual strategy corresponds to the “differentiated gonochoric” pattern. Histological analyses of adult gonads showed an asynchronous spawning mode for females and continuous spawning for males. Mature oocytes presented fluid yolk. Testis organization corresponded to a restricted spermatogonial model. Herein, we report the ultrastructural organization of the vitelline envelope and the main features of the sperm of A. charrua. Taking together these results also contribute to phylogenetic studies and …

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 …

Invertebrate Diversity In Taylor Valley Soils And Sediments, Amy M. Treonis, Diana H. Wall, Ross A. Virginia

Biology Faculty Publications

Explaining how ecosystems function across variable landscapes will require knowledge of biodiversity patterns. In particular, biodiversity studies of soils and sediments will help in understanding the linkages between ecosystem processes in both of these habitats (Freckman et al. 1997). Soils and sediments are domains for ecosystem processes such as decomposition and trace gas exchange. There are few studies, however, that have compared abundance and diversity of organisms in adjacent soils and sediments (Freckman et al. 1997). The goal of this study was to increase understanding of how the biotic communities involved in ecosystem processes are organized within an important feature …