Life Sciences Commons^™

Comparative Taphonomy And Paleoecology Of A Glaciomarine Fauna, Carboniferous (Westphalian- Namurian) La Capilla Fm., Argentina, Rex A. Hanger, Mohutsiwa Gabadirwe

Virginia Journal of Science

The Carboniferous La Capilla Fm. of the Calingasta-Uspallata basin of western Argentina contains a low diversity fauna inhabiting a continental shelf under glacial ice fronts advancing from the east. Distal glaciomarine sediments on these ice-influenced shelves of Gondwana are most commonly interpreted as being deposited under quiet, low-energy conditions. Ta­phonomic and paleoecologic analysis of a sample of the fauna reveals the following: low species richness, yet comparable equitability to coeval, tropi­cal faunas; low articulation ratios and high pedicle valve dominance for brachiopods; diverse corrasion modes, about half relatively high categories; one hundred percent fracturing of brachiopod shells, with carinate fracture …

Three-Dimensional Reconstructions Of Tadpole Chondrocrania From Historical Sections, Gary Radice, Mary K. Boggiano, Mark Desantis, Peter Larson, Joseph Oppong, Matthew Smetanick, Todd Stevens, James Tripp, Rebecca Weber, Michael Kerckhove, Rafael De Sá

Virginia Journal of Science

Reconstructing three dimensional structures (3DR) from histological sections has always been difficult but is becoming more accessible with the assistance of digital imaging. We sought to assemble a low cost system using readily available hardware and software to generate 3DR for a study of tadpole chondrocrania. We found that a combination of RGB can1era, stereomicro­scope, and Apple Macintosh PowerPC computers running NIH Image, Object Image, Rotater, and SURFdriver software provided acceptable reconstruc­tions. These are limited in quality primarily by the distortions arising from histological protocols rather than hardware or software.

Cartilage Regeneration On A Large Articular Surface Facilitated By Stress Shielding, Charles L. Mcdowell, Jennifer S. Wayne, Robert Tuten, Hunter H. Mcguire Jr.

Virginia Journal of Science

An animal model for the study of articular cartilage regeneration in-vivo facilitated by stress-shielding is introduced. The object of the model is to test the hypothesis that some form of cartilaginous tissue will grow upon a large joint surface in vivo with the joint in normal motion. The model utilizes the known capability of immature cells to differentiate. The source of cells is bleeding subchondral bone. In addition, the model provides a mechanically shielded environment in which cell differentiation and maturation can occur. The study showed that a substantial amount of tissue will grow in the animal model only when …

Pfiesteria Piscicida And Dinoflagellates Similar To Pfiesteria, Harold G. Marshall

Virginia Journal of Science

Pfiesteria pisiccida is a microscopic, unicellular organism that is classified as both a mixotrophic and heterotrophic dinoflagellate, which has been associated with both fish deaths and a cause of human illness (Burkholder et al., 1992; Glasgow et al., 1995; Burkholder and Glasgow, 1997). This species possesses a complex life cycle that includes motile forms (e.g. zoospores, gametes, amoebae) and a cyst stage that may remain dormant in the sediment (Burkholder et al., 1995b). Pfiesteria piscicida is known to have toxin and non-toxin producing populations, where cyst transformation into the toxic motile zoospores may be initiated by the presence of certain …

Conservation Status Of The Southern Appalachian Herpetofauna, Joseph C. Mitchell, Thomas K. Pauley, David I. Withers, Steven M. Roble, Brian T. Miller, Alvin L. Braswell, Paul V. Cupp Jr., Christopher S. Hobson

Virginia Journal of Science

Seventy one species of amphibians (55 salamanders, 16 anurans) and 46 species of reptiles (15 turtles, 8 lizards, 23 snakes) inhabit a five state area (Kentucky, North Carolina, Tennessee, Virginia, West Virginia) in the southern Appalachian region bordered by the Potomac River, the Blue Ridge Mountains, and the western margin of the Appalachian Plateau. Of these, 47.9 % of the amphibian fauna and 52.2 % of the reptilian fauna are listed as being of conservation concern by federal, state, and Natural Heritage programs in all or a portion of their ranges of this region. The Shenandoah salamander (Plethodon Shenandoah …

Characterization And Identification Of A Sludge-Associated Bacterial Isolate, Abiodun O. Adibi, Derrell Mcpherson, Minna Laine

Virginia Journal of Science

During a metal speciation study, an unusually high retention of lead ·was observed when lead solution was percolated through a column packed with sludge compost obtained from Hampton Roads Sanitation department. A bacterium was isolated from the sludge compost and identified as Bacillus sphaericus using electron microscopy, whole cell fatty acid analysis (Midi System) and Biolog GP Microplate. The isolate grows in broth and agar media containing up to 800 µM lead. Lead accumulation study using atomic absorption spectrophotometer indicates that the isolate adsorbs lead. Lead adsorption is pH dependent. The isolate contains a plasmid of approximately 40 -50 kbp …

Historical Relationships Of Atlantic Slope River Drainages, Eugene G. Maurakis, Diana L. Lipscomb

Virginia Journal of Science

An analysis of the historical relationships of 19 river drainages (St. Lawrence to Altamaha) on the Atlantic slope of the Appalachian Mountains was conducted using the shared presence of 124 native species of cyprinid fishes. This analysis resulted in an area cladogram that suggests that the rivers of the southern Atlantic slope were historically connected to the drainage of three southern rivers (Flint, Chattahoochee, and Apalachicola) which drain into the Gulf of Mexico. The mid Atlantic and northern Atlantic slope rivers appear to be historically related in support of earlier hypotheses that the mid Atlantic region provided a refugium for …

Possible Predation Scars On Rectithyris Subdepressa (Stoliczka, 1872), Late Cretaceous (Maastrichtian) Kallankurichi Fm., India, Rex Alan Hanger, Rama Krishnaswamy

Virginia Journal of Science

A single specimen of the terebratulid brachiopod, Rectithyris subdepressa (Stoliczka, 1872) from the Late Cretaceous (Maastrichtian) Kallankurichi Fonnation of southern India was found with durophagous predation traces. This occurrence is significant as it is possibly the first documentation of elasmobranch shark predation on brachiopods from the Mesozoic.

Pcr And Fish Detection Extends The Range Of Pfiesteria Piscicida In Estuarine Waters, P. A. Rublee, J. Kempton, E. Schaefer, J.M. Burkholder, H. B. Glasgow Jr., David Oldach

Virginia Journal of Science

PCR and fluorescent in situ hybridization probes were used to assay for the presence of the dinoflagellate Pfiesteria piscicida in 170 estuarine water samples collected from New York to northern Florida. 20% of samples tested positive for the presence of P. piscicida, including sites where fish kills due to Pfiesteria have occurred and sites where there was no historical evidence of such events. The results extend the known range of P. piscicida northward to Long Island, New York. The results also suggest that P. piscicida is common, and normally benign, inhabitatant of estuarine waters of the eastern US.

A Cohort Study To Determine The Epidemiology Of Estuary-Associated Syndrome, Elizabeth Turf, Lily Ingsrisawang, Megan Turf, J.D. Ball, Michael Stutts, John Taylor, Suzanne Jenkins

Virginia Journal of Science

From the Introduction:

Estuary-Associated Syndrome (EAS) is the name given to a potential illness characterized primarily by changes in an individual's cognitive abilities, including acute onset of memory loss or the sudden inability to solve simple problems. Other possible signs of illness include respiratory symptoms, skin rash, or gastrointestinal distress. This illness appears to arise following exposure to toxin produced by Pfiesteria piscicida, or other toxic dinoflagellates, that resides in estuary waters.

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In order to learn more about this possible syndrome and to determine if a causal relationship exists between association to waters containing Pfiesteria or other toxic …

Monitoring Results For Pfiesteria Piscidida And Pfiesteria-Like Organisms From Virginia Waters In 1998, Harold G. Marshall, David W. Seaborn, Jennifer Wolny

Virginia Journal of Science

Results of an extensive 1998 monitoring program for the presence of Pfiesteria-like organisms (PLO) in Virginia estuaries indicate these dinoflagellates are widely distributed in both the water column, and as cysts in the sediment, however Pfiesteria piscicida was not detected at this time. The highest concentrations of PLO were in estuaries along the Virginia shore line of the Potomac River, and in western Chesapeake Bay estuaries from the Little Wicomico River to the Rappahannock River. The most common PLO included Cryptoperidiniopsis sp. and Gymnodinium galatheanum. The lowest PLO concentrations were at ocean side locations. PLO were also …

Field Sampling And Necropsy Examination Of Fish, A. S. Kane, A. Baya, R. Reimschuessel, K. M. St. Pé, C. A. Poukish, C. P. Driscoll

Virginia Journal of Science

This paper presents an overview of observational and fish sampling tech­niques for investigating fish lesions, morbidity and mortality. These sam­pling techniques and investigations are much like detective work and require attention to detail, common sense, technical proficiency and experience. To solve the mystery of a fish kill, the investigator must use available evidence and clues to piece together a series of events that often have long since passed. The cause of these field events may be chemical, biological or physical; more often, it is some combination of these. An initial categorization approach may be used to reduce the great number …

Virginia's Pfiesteria Monitoring Program: Water Quality, Roger K. Everton, Wick T. Harlan, Jonathan W. Priest, Mark S. Alling

Virginia Journal of Science

During the summer and early fall of 1998, 34 estuarine stations in Virginia were sampled for Pfiesteria like organisms (PLOs) and associated water quality conditions. Stations were sampled either bimonthly (20 stations) or monthly (14 stations) from June to October 1998. At each station, a set of live and Lugol' s preserved samples were collected for presumptive counts of PLOs and water quality conditions were determined. Water quality parame­ters measured included standard field parameters, nutrients (total, dissolved, and particulate), chlorophyll a, and conventional water quality indicators. Although PLOs were relatively low in 1998 as compared to 1997, presump­tive PLO counts …

Foreward, Virginia Journal Of Science

Virginia Journal of Science

Foreward to the Winter 1999 issue of Virginia Journal of Science, discussing Pfiesteria Piscicida, written by Harold G. Marshall.

Growth And Feeding Studies On The Algal Feeding Stage Of A Pfiesteria-Like Dinoflagellate, David W. Seaborn, A. Michelle Seaborn, William M. Dunstan, Harold G. Marshall

Virginia Journal of Science

The dinoflagellate Cryptoperidiniopsis sp. was isolated from sediment samples taken from Virginia estuaries, and established in culture for subsequent growth and feeding studies. The maximum abundance, or yield, of Cryptoperidiniopsis is exponentially related to the concentration of algal prey and is saturated at about 4.00 X 10⁵ mL^-1. Salinity from 10-20 ppt and temperature between 15-25 C have no effect on the yield of this form of Cryptoperidiniopsis. Light intensity has a secondary effect in that the algal prey reproduces more quickly in higher light as they are being grazed. Growth rates of Cryptoperidiniopsis were …

Water Quality Relationships To Concentrations Of Pfiesteria-Like Organisms In Virginia Estuaries For 1998, Everett P. Weber, Harold G. Marshall

Virginia Journal of Science

A series of statistical analyses were performed to identify the relationship between abundance of dinoflagellates grouped as Pfiesteria-like organisms and a set of 25 water quality variables from May through October of 1998 at 41 estuarine locations. Although regions were identified in relation to seasonal density of cells present, there were no strong relationships to specific water quality variables. Factors that may have influenced these results included: a) several species were included in the group analyzed and this composite did not respond as a unit to changing environmental conditions; b) cell concentrations were low and there were a large …