Life Sciences Commons^™

Molecular Systematics Of The Middle American Genus Hypopachus (Anura: Microhylidae), Eli Greenbaum, Eric N. Smith, Rafael O. De Sá

Biology Faculty Publications

We present the first phylogenetic study on the widespread Middle American microhylid frog genus Hypopachus. Partial sequences of mitochondrial (12S and 16S ribosomal RNA) and nuclear (rhodopsin) genes (1275 bp total) were analyzed from 43 samples of Hypopachus, three currently recognized species of Gastrophryne, and seven arthroleptid, brevicipitid and microhylid outgroup taxa. Maximum parsimony (PAUP), maximum likelihood (RAxML) and Bayesian inference (MrBayes) optimality criteria were used for phylogenetic analyses, and BEAST was used to estimate divergence dates of major clades. Population-level analyses were conducted with the programs NETWORK and Arlequin. Results confirm the placement of Hypopachus …

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 …

Oak Galls: A Strange Biology Indeed!, W. John Hayden

Biology Faculty Publications

Anyone who takes the time to look closely at several branches of oak will soon find one or another peculiar anomaly among the leaves and twigs. One can easily find structures resembling Ping-Pong balls, hard knots, fluffy tufts, horns—either single or clustered, or irregular thickenings, to mention just a few possibilities. These abnormal growths are galls, structures caused by the presence of small insect larvae living inside the tissue of the plant. Galls can be found on a wide variety of plants. They are common, for example, on the stems of goldenrods, and the leaves of maples, but oaks are …

Rna Interference In Marine And Freshwater Sponges: Actin Knockdown In Tethya Wilhelma And Ephydatia Muelleri By Ingested Dsrna Expressing Bacteria, Ajna S. Rivera, April L. Hill, Et. Al.

Biology Faculty Publications

Background: The marine sponge Tethya wilhelma and the freshwater sponge Ephydatia muelleri are emerging model organisms to study evolution, gene regulation, development, and physiology in non-bilaterian animal systems. Thus far, functional methods (i.e., loss or gain of function) for these organisms have not been available.

Results: We show that soaking developing freshwater sponges in double-stranded RNA and/or feeding marine and freshwater sponges bacteria expressing double-stranded RNA can lead to RNA interference and reduction of targeted transcript levels. These methods, first utilized in C. elegans, have been adapted for the development and feeding style of easily cultured marine and freshwater poriferans. …

Life History Benefits Of Residency In A Partially Migrating Pond-Breeding Amphibian, Kristine L. Grayson, Larissa L. Bailey, Henry M. Wilbur

Biology Faculty Publications

Species with partial migration, where a portion of a population migrates and the other remains residential, provide the opportunity to evaluate conditions for migration and test mechanisms influencing migratory decisions. We conducted a five-year study of two populations of red-spotted newts (Notophthalmus viridescens), composed of individuals that either remain as residents in the breeding pond over the winter or migrate to the terrestrial habitat. We used multistate mark-recapture methods to (1) test for differences in survival probability between migrants and residents, (2) determine if migrants breed every year or skip opportunities for reproduction, and (3) estimate the frequency …

White Oak Part Of Global Oak Presence, W. John Hayden

Biology Faculty Publications

As we act locally celebrating white oak, Quercus alba, as the 2011 VNPS Wildflower of the Year, it is perhaps appropriate to think globally for a few moments and consider the breadth of diversity encompassed by the oaks. Quercus is a big genus, easily the largest in its family, the Fagaceae. Approximately 400 species of oak are known, and they are widely distributed in the northern hemisphere. We tend to think of oaks as temperate zone trees, but in the New World, their range extends south through the mountains of Central America to Colombia and in the Old World, …

Hybrid Oaks: Full Of Vexation And Wonder, W. John Hayden

Biology Faculty Publications

Distinguishing different species of oak in the forests of eastern North America can be challenging. For one thing, there are simply a lot of different species to sort out. A recent reference (Stein et al. 2003), describes 50 species in the genus Quercusoccurring naturally east of the 100th meridian, and 90 species are distinguished for all of North America north of Mexico (Nixon 1997). With so many species to parse, confident identification requires careful study of leaves, stem and leaf hairiness, and fully mature acorns with their caps. But care is not always enough, because in addition to the …

2011 Wildflower Of The Year: White Oak, Quercus Alba, W. John Hayden

Biology Faculty Publications

Emblematic of strength and longevity, white oaks grace the deciduous forests of eastern North America.

Variation, Systematics, And Relationships Of The Leptodactylus BolivianusComplex (Amphibia: Anura: Leptodactylidae), W. R. Heyer, Rafael O. De Sá

Biology Faculty Publications

A cluster of morphologically similar frogs of the genus Leptodactylus having a pair of distinct dorsolateral folds on the dorsum and well-developed lateral fringes on the toes has never been systematically evaluated by examining materials from throughout its geographic range. The species involved are herein referred to as members of the Leptodactylus bolivianus complex. There have been three names proposed for members of this complex: Leptodactylus bolivianus Boulenger, 1898; Leptodactylus insularum Barbour, 1906; and Leptodactylus romani Melin, 1941. The collective range for the L. bolivianus complex is from Costa Rica southward through Panama, extending across northern South America (east of …

Variation, Systematics, And Relationships Of The Leptodactylus Bolivianus Complex (Amphibia: Anura: Leptodactylidae), W. Ronald Heyer, Rafael O. De Sá

Biology Faculty Publications

Heyer, W. Ronald, and Rafael O. de Sá. Variation, Systematics, and Relationships of the Leptodactylus bolivianus Complex (Amphibia: Anura: Leptodactylidae). Smithsonian Contributions to Zoology, number 635, viii + 58 pages, 21 figures, 20 tables, 2011.—The Leptodactylus bolivianuscomplex has been considered to consist of one or two species, L. bolivianus alone or L. bolivianus and L. insularum. Detailed morphological analyses were undertaken to evaluate variation in the complex, which ranges from Costa Rica through Panama, across northern South America in the river valleys draining to the Caribbean, and throughout much of the Amazon basin with southern limits in Bolivia. Members of …