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Systematic Ichthyofaunal Surveys In Urban And Non-Urban Watersheds, Eugene G. Maurakis, David V. Grimes, Amanda Schutt, Suzy Short Jan 2013

Systematic Ichthyofaunal Surveys In Urban And Non-Urban Watersheds, Eugene G. Maurakis, David V. Grimes, Amanda Schutt, Suzy Short

Virginia Journal of Science

Objectives were to model fish species richness relative to natural and anthropogenic variables in Quantico Creek, a forested undisturbed stream environment, and Cameron Run, a highly disturbed urban stream environment in the lower Piedmont-Fall Line region of the Potomac River watershed. Species richness in all stream orders (e.g. avg. range=2.5-9.65 in 1st-3rd orders) of Quantico Creek were significantly higher than those (e.g. avg. range=2.1- 7.6 in 1st -4th orders) of Cameron Run. Fish species richness in Quantico Creek watershed can be modeled by eight factors: season, stream order, elevation, river km, stream width and depth, watershed size, and percent of …


Phytoplankton In Virginia Lakes And Reservoirs, Harold G. Marshall Jan 2013

Phytoplankton In Virginia Lakes And Reservoirs, Harold G. Marshall

Biological Sciences Faculty Publications

This study involves a phytoplankton summer/autumn survey in 46 Virginia lakes and reservoirs during 2010-2012. A total of 307 taxa were identified which included several filamentous and colonial cyanabacteria in bloom concentrations. With the exception of one natural lake, the other sites sampled represent impoundments created decades ago, with the majority presently classified as meso- or eutrophic. Among the cyanobacteria were 6 known toxin producers (Anabaena circinalis, Anabaena spiroides, Aphanizomenon flos-aquae, Cylindrospermopsis raciborskii, Limnothrix redekei, and Microcystis aeruginosa). The study characterizes phytoplankton populations in these aging freshwater habitats taken from a large number …


Chemical Defense Of An Asian Snake Reflects Local Availability Of Toxic Prey And Hatchling Diet, D. A. Hutchinson, A. H. Savitzky, G. M. Burghardt, C. Nguyen, J. Meinwald, F. C. Schroeder, A. Mori Jan 2013

Chemical Defense Of An Asian Snake Reflects Local Availability Of Toxic Prey And Hatchling Diet, D. A. Hutchinson, A. H. Savitzky, G. M. Burghardt, C. Nguyen, J. Meinwald, F. C. Schroeder, A. Mori

Biological Sciences Faculty Publications

Species that sequester toxins from prey for their own defense against predators may exhibit population-level variation in their chemical arsenal that reflects the availability of chemically defended prey in their habitat. Rhabdophis tigrinus is an Asian snake that possesses defensive glands in the skin of its neck (nuchal glands'), which typically contain toxic bufadienolide steroids that the snakes sequester from consumed toads. In this study, we compared the chemistry of the nuchal gland fluid of R.tigrinus from toad-rich and toad-free islands in Japan and determined the effect of diet on the nuchal gland constituents. Our findings demonstrate that captive-hatched juveniles …


Does Pitcher Plant Morphology Affect Spider Residency?, Marc A. Milne, Deborah A. Waller Jan 2013

Does Pitcher Plant Morphology Affect Spider Residency?, Marc A. Milne, Deborah A. Waller

Biological Sciences Faculty Publications

Spiders are often found as residents in association with Sarracenia purpurea ( Purple Pitcher Plant). Many spiders choose web locations based on environmental cues such as vegetation structure and composition, prey density, temperature, and humidity. To determine if spiders use cues from the Purple Pitcher Plant to build their webs, we conducted a field study using variants of the plant that separated various morphological features: nectar, pigment, and the presence of prey. There was no difference in spider residency across all treatments and no difference in male/female or mature/immature residency. Linyphiids were the most common residents, possibly due to pitcher …


Phytoplankton In Virginia Lakes And Reservoirs, Harold G. Marshall Jan 2013

Phytoplankton In Virginia Lakes And Reservoirs, Harold G. Marshall

Virginia Journal of Science

This study involves a phytoplankton summer/autumn survey in 46 Virginia lakes and reservoirs during 2010-2012. A total of 307 taxa were identified which included several filamentous and colonial cyanabacteria in bloom concentrations. With the exception of one natural lake, the other sites sampled represent impoundments created decades ago, with the majority presently classified as meso- or eutrophic. Among the cyanobacteria were 6 known toxin producers (Anabaena circinalis, Anabaena spiroides, Aphanizomenon flos-aquae, Cylindrospermopsis raciborskii, Limnothrix redekei, and Microcystis aeruginosa). The study characterizes phytoplankton populations in these aging freshwater habitats taken from a large number …


Effect Of Laser Ablation Depth In Otolith Life History Scans, Renée R. Hoover, Cynthia M. Jones Jan 2013

Effect Of Laser Ablation Depth In Otolith Life History Scans, Renée R. Hoover, Cynthia M. Jones

OES Faculty Publications

Life history scans of fish otoliths are bringing new insight into the structure, connectivity, and movement of fish populations. Data obtained from such scans, however, possess in-herent limitations that have not yet been fully addressed or understood. For example, several investigators have noted delays in otolith elemental uptake that do not appear to reflect habitat exposure. We hypothesized that the 3-dimensional structure of otoliths may produce sampling artifacts in the results obtained from laser ablation scans. To test this hypothesis, we sampled sagittal otoliths from juvenile Atlantic croaker Micropogonias undulatus with laser ablation inductively coupled plasma mass spectrometry to obtain …