Animal Sciences Commons^™

Geographic Variation In The Morphology Of Crotalus Horridus (Serpentes: Viperidae), John Robert Allsteadt

Biological Sciences Theses & Dissertations

The Timber Rattlesnake (Crotalus horridus) occurs in discontinuous populations throughout the eastern and central United States. The species exhibits high levels of polymorphism in morphological traits, especially in coloration and pattern. Previous studies recognized either distinct northern and southern subspecies or three regional morphs (northern, southern, and western), but conflicting data sets and limited geographic sampling of previous studies have left the relationships among those regional variants unclear. In this study, univariate and multivariate statistics, together with a geographic information system, were used to analyze geographic variation in 36 morphological characters recorded from 2,420 specimens of C. horridus …

Mechanical Properties Of The Integument Of The Common Gartersnake, Thamnophis Sirtalis (Serpentes: Colubridae), Gabriel Rivera

Biological Sciences Theses & Dissertations

The evolution of the ophidian feeding mechanism has involved substantial morphological restructuring associated with the ability to ingest relatively large prey. Previous studies examining the morphological consequences of macrophagy have concentrated on modifications of the skull and cephalic musculature. Although it is evident that macrophagy requires highly compliant skin, the mechanical properties of the ophidian integument have received limited attention, particularly in the context of feeding. I examined mechanical properties of skin along the body axis in male Thamnophis sirtalis (Colubridae). From each of 11 specimens, I examined nine circumferential strips of skin, each spanning 10 ventral scales, spaced at …

An Unusually Colored Red-Backed Salamander (Plethodon Cinerus) From Northern Virginia, Joseph C. Mitchell, Thomas K. Pauley, C. Todd Georgel

Virginia Journal of Science

We describe an orange-pink, patternless, translucent morph of the Red-backed Salamander (Plethodon cinereus) found in northern Virginia on 27 September 2001. This is the first description of this unusual phenotype in this terrestrial salamander.

Keys To The Mammals And Mammal Skulls Of The Northern Coastal Plain Of Virginia, John F. Pagels, A. Scott Bellows, Joseph C. Mitchell

Virginia Journal of Science

This publication is designed to function as a tool for the identification of mammal species that occur on the Coastal Plain of northern Virginia. We provide whole-body and skull keys to the 40 species that occur in this region. Baseline data for this work were collected during several studies conducted on Fort A.P. Hill, Caroline County. The intended audience includes interested naturalists, teachers, students, field biologists, and natural resource managers.

The Ecological Ramifications Of Disease And Density In The Caribbean Spiny Lobster, Panulirus Argus, Donald C. Behringer Jr.

Biological Sciences Theses & Dissertations

In 1999, I discovered the first virus known to be pathogenic to any species of lobster. HLV-PA is a pathogenic herpes-like virus that infects juvenile Caribbean spiny lobster, Panulirus argus, in the waters off south Florida (USA), and it alters the behavior and ecology of this species in fundamental ways. Gross signs of HLV-PA infection are lethargy, morbidity, cessation of molting, and discolored, “milky” hemolymph that does not clot. HLV-PA infects the hemocytes of host lobsters, specifically the hyalinocytes and semi-granulocytes, but not the granulocytes. When hemolymph from infected donors was injected into healthy juvenile lobsters, 90% of the …

Hybridization Between The Watersnakes Nerodia Sipedon And Nerodia Fasciata, In The Carolinas: A Morphological And Molecular Approach, Konrad Mebert

Biological Sciences Theses & Dissertations

A few traditionally applied diagnostic characters of color pattern were compared with an additional set of morphological and genetic characters to evaluate differences between Nerodia sipedon and N. fasciata and to study the dynamics across their hybrid zone in the Carolinas. Many of the morphological characters exhibited significant interspecific differences, although only the number of dorsally complete crossbands (CBa) was diagnostic by itself. A discriminant function analysis of morphological characters was successful in separating both taxa. Species-specific nuclear markers, identified by the AFLP (Amplified Fragment Length Polymorphism) technique were nearly fixed and served as diagnostic markers. They revealed extensive introgression …

Male Reproductive Dynamics In The Caribbean Spiny Lobster Panulirus Argus, Jamie S. Heisig

Biological Sciences Theses & Dissertations

The population size structure of the Caribbean Spiny Lobster, Panulirus argus, in the Florida Keys, Florida (USA) has undergone a dramatic shift as a result of fishing pressure on the large individuals of the population. Male lobsters are affected most by fishing because of sexual dimorphism in size and other studies have shown that male size has direct impacts on reproductive output (i.e., number of fertilized eggs/clutch) that are independent of female size. To assess more precisely the impact of male size on fertilization success, I conducted laboratory experiments and field observations to examine various male reproductive attributes over …

Experimental Mycobacteriosis In Striped Bass Morone Saxatilis, D. T. Gauthier, M. W. Rhodes, W. K. Vogelbein, H. Kator, C. A. Ottinger

Biological Sciences Faculty Publications

Striped bass Morone saxatilis were infected intraperitoneally with approximately 10⁵ Mycobacterium marinum, M. shottsii sp. nov., or M. gordonae. Infected fish were maintained in a flow-through freshwater system at 18 to 21°C, and were examined histologically and bacteriologically at 2, 4, 6, 8, 17, 26, 36 and 45 wk post-infection (p.i.). M. marinum caused acute peritonitis, followed by extensive granuloma development in the mesenteries, spleen and anterior kidney. Granulomas in these tissues underwent a temporal progression of distinct morphological stages, culminating in well-circumscribed lesions surrounded by normal or healing tissue. Mycobacteria were cultured in high numbers from …

Chemical Composition Of Some Components Of The Arrestment Pheromone Of The Black-Legged Tick, Ixodes Scapularis (Acari : Ixodidae) And Their Use In Tick Control, Daniel E. Sonenshine, Trevor Adams, Sandra A. Allan, John Mclaughlin, Francis X. Webster

Biological Sciences Faculty Publications

Chemical analysis (high-performance liquid chromatography) and bioassay demonstrated the presence of compounds that seem to be components of the Ixodes scapularis arrestment pheromone. Only two purines, guanine and xanthine, were found in acidified saline extracts made from cast skins after molting of fed nymphs, fed larvae, and fecal/excretory exudates deposited by unfed adults on substrates in their environment. The ratio of guanine to xanthine was 10.6:1 in an extract from the nymphal skins versus 0.95:1 in an extract from the larval skins. Guanine, xanthine, and traces of a third purine, tentatively identified as 8-azaguanine, were found in extracts made from …

Hydrodynamic Stability Of Swimming In Ostraciid Fishes: Role Of The Carapace In The Smooth Trunkfish Lactophrys Triqueter (Teleostei : Ostraciidae), Ian K. Bartol, Morteza Gharib, Daniel Weihs, Paul W. Webb, Jay R. Hove, Malcolm S. Gordon

Biological Sciences Faculty Publications

The hydrodynamic bases for the stability of locomotory motions in fishes are poorly understood, even for those fishes, such as the rigid-bodied smooth trunkfish Lactophrys triqueter, that exhibit unusually small amplitude recoil movements during rectilinear swimming. We have studied the role played by the bony carapace of the smooth trunkfish in generating trimming forces that self-correct for instabilities. The flow patterns, forces and moments on and around anatomically exact, smooth trunkfish models positioned at both pitching and yawing angles of attack were investigated using three methods: digital particle image velocimetry (DPIV), pressure distribution measurements, and force balance measurements. Models …

Demographic Assessment Of The Blue Crab (Callinectes Sapidus) In Chesapeake Bay Using Extractable Lipofuscins As Age Markers, Se-Jong Ju, David H. Secor, H. Rodger Harvey

OES Faculty Publications

The blue crab (Callinectes sapidus) plays an important economic and ecological role in estuaries and coastal habitats from the Gulf of Mexico to the east coast of North America, but demographic assessments are limited by length-based methods. We applied an alternative aging method using biochemical measures of metabolic byproducts (lipofuscins) sequestered in the neural tissue of eyestalks to examine population age structure. From Chesapeake Bay, subsamples of animals collected from the 1998-99 (n-769) and 1999-2000 (n=367) winter dredge surveys were collected and lipofuscin was measured. Modal analysis of the lipofuscin index provided separation into three modes, whereas carapace-width …

The Effect Of A Predator Gradient On Female Oviposition Site Selection And Larval Performance, Josef F. Rieger

Biological Sciences Theses & Dissertations

Patterns of larval amphibian distribution and abundance have historically been ascribed to direct predation. However, adult oviposition site selection is an alternative mechanism that can produce identical patterns and significantly influence community assembly. Although such behavioral habitat selection has been documented in several amphibian species whose larvae lack particular anti-predator defenses, the sensitivity of adult amphibians in detecting predator cues and avoiding these habitats has not yet been determined. If larval survivorship is greatly reduced in sites containing predatory fish, selection to detect and avoid habitats with low fish densities should be strong. I conducted three experiments which, (1) evaluated …

Reproduction Of Black Drum, Pogonias Cromis, From The Chesapeake Bay Region, Brian K. Wells, Cynthia M. Jones

Virginia Journal of Science

Ovaries of black drum, Pogonias cromis, collected from the Chesapeake Bay region in 1992, were used to describe reproductive strategy and fecundity. Histological examination showed that black drum spawn in the Chesapeake Bay region from April through early June. Distributions of oocyte diameter showed distinct oocyte-developmental groups indicating that Chesapeake Bay black drum are group-synchronous batch spawners. Female black drum are extremely fecund ranging from 414,000 to 3,736,000 hydrated oocytes (mean = 1,389,000) per batch with a spawning periodicity of 3.8 days. Estimates of spawning strategy, spawning periodicity, and batch fecundity for black drum from the Chesapeake Bay region …

Autotrophic Picoplankton: Their Presence And Significance In Marine And Freshwater Ecosystems, Harold G. Marshall

Virginia Journal of Science

Invited lecture: Autotrophic Picoplankton Workshop, 52nd Congress of the Polish Botanical Society, Adam Mickiewicz University, Poznan, Poland, September 2001 .

Reproductive Differences Among Delmarva Grass Shrimp (Palaemonetes Pugio And P. Vulgaris) Populations, Holly H. Ganz, Robert E. Knowlton

Virginia Journal of Science

Populations of female grass shrimps (Palaemonetes pugio and P. vulgaris) were sampled from five coastal embayments in Delaware, Maryland, and Virginia (Delmarva) and compared with respect to reproductive and life history attributes. We observed interspecific differences in timing of reproduction, carapace length, ratio of carapace length to total body length, body weight, clutch weight, clutch size, and egg volume. Onset of reproduction in P. vulgaris lagged behind P. pugio. Although there was no difference in the relationship between clutch size and carapace length for the two species, carapace length/total body length in P. pugio was greater than …

Anting Behavior In Birds: Ant Selection And Effect Of Ant Chemistry On Feather Ectoparasites, Hannah Carrington Revis

Biological Sciences Theses & Dissertations

Active anting behavior occurs when songbirds apply ants to their feathers. During anting displays, a bird draws its wings forward in front of the head and swings its tail around to the far right or left. Both wing and tail feathers are then rubbed with ants held in the bird's beak. The potential associations among ants, feather ectoparasites and birds make anting behavior an important community-level interaction. Although this behavior is cosmopolitan in distribution and occurs in a wide variety of passerine birds, it remains poorly understood. This dissertation tested hypotheses about anting behavior through controlled experiments with captive songbirds …

Vertical Distributions Of Zooplankton At The Mouth Of Chesapeake Bay And Calibration Of Backscatter From An Acoustic Doppler Current Profiler, Arthur Keith Jenkins

Biological Sciences Theses & Dissertations

This study investigated the physical factors influencing the vertical distribution of zooplankton at the mouth of the Chesapeake Bay and attempted to derive biological data from acoustic Doppler current profiler (ADCP) backscatter. A single site was occupied in the North Channel at the mouth of Chesapeake Bay (37° 04' N, 75° 58' W) from 17.0–19.7 November 1999. Temperature, salinity, fluorescence, light transmission, current velocity and backscatter were measured throughout the sampling period. Plankton samples were collected every hour from 3.5, 7.5, and 11.5 m.

We found little association between ADCP backscatter and plankton concentrations, but stronger correlations between backscatter and …

Length-At-Age In Juvenile Patagonian Toothfish (Dissostichus Eleginoides), J. Ashford, C. Jones, S. Bobko, I. Everson

OES Faculty Publications

We used the otoliths from a sample of Dissostichus eleginoides pre-recruits, whose length density was distinctly polymodal, to see whether ages estimated by reading otoliths were congruent with the length modes observed. Length densities by age were compared graphically with the overall length density observed. Additionally, ages were predicted for each fish based on length, and compared with ages estimated from reading otoliths in a goodness-of-fit test. The majority of the otoliths (83.6%) were estimated to be from fish 1+ or 2+ years old, with mean total lengths of 32.5 cm and 41.3 cm respectively. No difference was found between …

Response Of Anchovy (Engaulis Ringens) Off Northern Chile To The 1997-1999 El Niño-La Niña Sequence, José L. Blanco, Patricio Barria, Jorge Castillo, Larry P. Atkinson

CCPO Publications

No abstract provided.

Evidence For Infanticide In Bottlenose Dolphins Of The Western North Atlantic, Dale G. Dunn, Susan G. Barco, D. Ann Pabst, William A. Mclellan

Biological Sciences Faculty Publications

Nine bottlenose dolphin (Tursiops truncatus) calves that stranded in Virginia in 1996 and 1997 died of severe blunt-force trauma. Injuries were concentrated on the head and chest and multiple rib fractures, lung lacerations, and soft tissue contusions were prominent. Skeletal and/or soft tissue trauma occurred bilaterally in all of the calves. One had a bite wound across the left mandible that exhibited deep punctures consistent with the tooth placement in an adult bottlenose dolphin. The lesions were not compatible with predation, boat strike, fisheries interactions, rough-surf injury, or blast injury. However, they were similar to traumatic injuries described in stranded …

Mammals Of Fort A. P. Hill, Caroline County, Virginia And Vicinity, A. Scott Bellows, Joseph C. Mitchell, John F. Pagels, Heather N. Mansfield

Virginia Journal of Science

Fort A.P. Hill (APH) is a 30,329 ha military training installation (U.S. Army) located in the upper Coastal Plain of Caroline County, Virginia. It was formed in 1941 and named in honor of Civil War Confederate Lt. General Ambrose Powell Hill. The current landscape includes a mosaic of habitats that range from old fields to hardwood forests. Forty species of mammals are known to exist on or near the installation. These include one marsupial, five insectivores, 9 chiropterans, one lagomorph, 12 rodents, 10 carnivores, and one cervid. We have studied many of the species on APH since 1997. In this …

Development Of An Electrotransformation Technique For Streptococcus Iniae And Preliminary Characterization Of The Hemolysin Associated With This Bacterium, Kimberly Ann Hahn

Biological Sciences Theses & Dissertations

Streptococcus iniae is a gram-positive organism responsible for causing disease in both freshwater as well as saltwater fish. Every year fisheries lose fish by the tons due to diseases caused by this organism. In 1991, the first reported human case of disease associated with this organism was described. Since this initial case, there have been numerous other reported cases of S. iniae infections. This organism is a catalase negative, facultatively anaerobic organism that produces a capsule and when plated onto blood agar demonstrates β-hemolytic activity.

In this study, the relationship between the hemolysin produced by S. iniae and the lactate …

Effects Of Human Disturbances On The Behavior Of Dabbling Ducks, Melissa Lynn Pease

Biological Sciences Theses & Dissertations

Disturbance of wintering and migrating birds by human activities can cause birds to expend energy in avoidance of humans and reduces the time available for resting and feeding at a time in the annual cycle when fat deposition and energy conservation are important. Also, human disturbances can effectively cause habitat loss by displacing birds from feeding or resting habitat. Managers of natural resources are increasingly faced with decisions about the types and amounts of public use that should be allowed without lowering the value of the resource for wildlife. In order for managers to make decisions about how to minimize …

In Support Of A Rationally Managed Fishery: Age And Growth In Patagonian Toothfish (Dissostichus Eleginoides), Julian R. Ashford

Biological Sciences Theses & Dissertations

Patagonian toothfish (Dissostichus eleginoides) occur on the continental shelves and shelf breaks of southern South America and the Southern Ocean. Stock structure, critical to good fisheries management, can be inferred from growth differences between areas, but available growth data are compromised by inconsistencies in age estimation methods, sampling and sample sizes, and techniques used to derive estimates. I asked the scientific question: how is growth in Patagonian toothfish structured spatially within the Southern Ocean? I developed a multi-stage randomized design to sample fish caught by commercial longline, and an age estimation methodology. Because toothfish are difficult to age, …

Investigations Into The Innate Resistance Of The Tick, Dermacentor Variabilis, When Challenged With The Bacterium, Escherichia Coli, Shane Michael Ceraul

Biological Sciences Theses & Dissertations

In addition to the soluble response, many invertebrates control bacterial infections by means of phagocytosis or melanotic encapsulation. In some insects, Escherichia coli growth is reported to be inhibited by aggregation/encapsulation. Soluble and phagocytic responses to bacterial challenge have been reported in ticks, but evidence of an aggregation/encapsulation response was reported only for inanimate (araldite) implants. This study was done to determine how ticks control infection by E. coli. Ticks were challenged by direct inoculation of bacteria into the hemocoel cavity. Using plate counts, no viable E. coli were detected I hour post-inoculation. A direct fluorescence assay (DF A) …

Twenty-Five Years Of Population Fluctuations Of Microtus Ochrogaster And M-Pennsylvanicus In Three Habitats In East-Central Illinois, Lowell L. Getz, Joyce E. Hofmann, Betty Mcguire, Thomas W. Dolan Iii

Biological Sciences Faculty Publications

Populations of 2 species of arvicoline rodents, the prairie vole (Microtus ochrogaster) and meadow vole (M. pennsylvanicus), were monitored monthly in alfalfa, bluegrass, and tallgrass prairie habitats in east-central Illinois from 1972 through 1997. Alfalfa provides very highquality preferred food and poor vegetative cover for both vole species, whereas bluegrass provides intermediate food and vegetative cover. Preferred food resources were very low, especially for M. ochrogaster, and vegetative cover was very dense in tallgrass prairie. Maximum and mean population densities of M. ochrogaster were highest in alfalfa, intermediate in bluegrass, and lowest in tallgrass prairie. …

Growth Rate Variability And Lipofuscin Accumulation Rates In The Blue Crab Callinectes Sapidus, Se-Jong Ju, David H. Secor, H. Rodger Harvey

OES Faculty Publications

To better understand growth and age-pigment (lipofuscin) accumulation rates of the blue crab Callinectes sapidus under natural conditions, juveniles (33 to 94 mm carapace width) were reared in outdoor ponds for over 1 yr. Growth rates, measured by carapace width, during summer and fall exceeded all those reported in the literature; the initial carapace width of 59 ± 14 mm (mean ± SD) increased to 164 ± 15 mm within a 3 mo period. No growth occurred during winter months (November to April) at low water temperatures. Growth rates of crabs in ponds were substantially higher (von Bertalanffy growth parameter …

Yield-Per-Recruit Analysis For Black Drum, Pogonias Cromis, Along The East Coast Of The United States And Management Strategies For Chesapeake Bay, Cynthia M. Jones, Brian K. Wells

OES Faculty Publications

Black drum, Pogonias cromis along the U.S. East Coast is subject to commercial and recreational harvest. However, prior to this study no modeling had been undertaken to examine the potential for overfishing in the Chesapeake Bay region. We present evidence from yield-per-recruit models that growth overfishing of black drum is unlikely under current fishing practices in this region. Particular attention was given to fishing practices in the Chesapeake Bay region where old, large fish predominate in the commercial and recreational catches (mean age=26 years: mean total length=108.4 cm; mean weight 22.1 kg). Yield-per-recruit model results showed that growth overfishing was …

The 6th International Conference And Workshop On Lobster Biology And Management: An Introduction, Mark J. Butler Iv

Biological Sciences Faculty Publications

Every three years or so, the International Conference and Workshop on Lobster Biology and Management (ICWL) brings together lobster scientists, fishery managers, and industry representatives from around the world for a week of scientific presentations, workshops, and discussions on lobster biology and management. The first ICWL was held in Perth, Australia, in January 1977. Its purpose was to bring together a small group of lobster researchers from the USA and Australia to discuss common issues and themes. That initial workshop spawned a continuing series of meetings that have become the international lobster conference for scientists—the equivalent of an international congress …

Small Mammal Communities In Riparian And Upland Habitats On The Upper Coastal Plain Of Virginia, A. Scott Bellows, Joseph C. Mitchell

Virginia Journal of Science

We compared small mammal communities between riparian (stream corridor) and nearby upland habitats in a hardwood forest ecosystem on Fort A.P. Hill, Caroline County, Virginia. We used a combination of small-scale drift fence/pitfall trap arrays and snap traps to capture small mammals during April – October 1998, with an additional winter sample in January 1999. We captured seven small mammal species at 14 sites (7 pairs). Numbers of species were not significantly different between habitat types. Bray-Curtis polar ordinations showed that plant and small mammal community compositions were similar in upland sites and that these communities were most varied in …