Ecology and Evolutionary Biology Commons^™

A Molecular Phylogeny Of The Grunts (Perciformes: Haemulidae) Inferred From Nuclear Rag1 Gene Sequences, Millicent D. Sanciangco

Biological Sciences Theses & Dissertations

Species and genera of Haemulidae have undergone various taxonomic revisions, however, there is no study that infers the phylogeny of the haemulid genera using morphological or molecular data. The purpose of this study was to use approximately 1386 base pairs of the nuclear Recombination Activation Gene-I (RAG1) from 35 haemulid species representing 13 genera, one species of the closely related Inermiidae, and two species of the outgroup Sparidae to infer an intrafamilial phylogeny of Haemulidae. This analysis is corroborated using approximately 650 base pairs of the mitochondrial Cytochrome Oxidase I (COI) gene and RAG I-COI combined gene analyses of27 haemulids, …

The Effects Of Dredged Materials On The Copeod, Acartia Tonsa, Renee Suzanne Crouch

Biological Sciences Theses & Dissertations

A study was conducted to determine the potential impact of open ocean disposal of sediments dredged from a highly industrialized seaport. Sediments from three potential dredge sites along the Southern Branch of the Elizabeth River, Hampton Roads, Virginia were evaluated for acute toxicity. The suspended particulate fractions of dredged materials were tested in a series of 96-hour, static bioassays using the calanoid copepod, Acartia tonsa Dana. Significant mortalities were observed for all three sites with the sediments from the most heavily industrialized site producing immediate and severe mortality. Analysis of results indicates that mortality was highly related to the volatile …

The Effects Of The Mud Snail Ilyanassa Obsoleta (Say) Upon The Benthic Community Of Broad Bay, Virginia, Wick Timothy Harlan

Biological Sciences Theses & Dissertations

The effects of the presence of the mud snail Ilyanassa obsoleta (Say) upon the benthic community of Broad Bay, Virginia were examined through artificial removal and exclusion of the snail and artificial increase of the snail population. The enclosure treatment exhibited a significantly higher number of macrofaunal individuals than the control. The control had a significantly higher number of meiofaunal individuals than either treatment. There were no significant differences for the chlorophyll a. The increase in macrofauna and corresponding decrease in meiofauna were probably due to cage effects and not snail densities. The presence of the fences can act as …

The Effect Of Crowding On Growth Of The Cichlid Fish, Oreochromis Mossambicus, Bonnie A. Barrows

OES Theses and Dissertations

It has been reported that the Java tilapia, Oreochromis mossambicus, displays hypersensitivity to a substance it produces when biomass levels in a flow-through culture system exceed 20 g/1, resulting in reduced growth and high mortality. Experiments on the growth of this species in small tanks were conducted in order to determine whether O. mossambicus produces a growth-inhibiting compound under crowded conditions. This species was successfully maintained at biomass levels of 38 g/1 and 57 g/1 with a total mortality of only 4.5%.

The Java tilapia can grow rapidly in small aquaria, as indicated by the data taken during Experiment …

Feeding Behavior Of Three Species Of Spionid Polychaetes, Thomas Lane Stokes Jr.

Biological Sciences Theses & Dissertations

Observations of feeding behavior of three species of spionid polychaetes (Paraprionospio pinnata, Polydora ligni, and Streblospio benedicti) were performed in currents ranging from 0 to 10 cm/sec over fine and coarse sediments and in high and low suspended particle loads. These interface feeders may suspension feed, deposit feed, or both simultaneously using a pair of anterior tentaculate feeding palps. P. ligni and S. benedicti were found to alter their palp behaviors in response to experimental manipulations. P. ligni reacted strongly to currents by suspension feeding with coiled palps. S. benedicti reacted strongly and complexly to food particle type and availability. …

Determining The Uptake And Possible Assimilation Of The Plant Component Of Spartina Detritus By Palaemonetes Pugio Using A Rapid Radiolabeling Method, Michael Peter Crosby

Biological Sciences Theses & Dissertations

Assimilation of the plant components of Spartina alterniflora detritus by the grass shrimp, Palaemonetes pugio, was investigated in a laboratory feeding study. A new radiolabeling procedure was utilized to label the sterilized detritus with ¹⁴C. Organic carbon values were calculated for both S. alterniflora and P. pugio. The grass shrimp were found to assimilate significantly the detritus, with an assimilation efficiency of approximately 14%, and an approximate ingestion rate of 2.508 x l0^-4mg C detritus/mg C shrimp hour^-l occurred. It is hypothesized that coprophagous activity may be important to the completion of digestion of …

A Structural Analysis Of Phytoplankton In The Chesapeake Bay Plume And Adjacent Shelf Waters, Charles K. Rutledge

Biological Sciences Theses & Dissertations

Community structures of phytoplankton populations from the southern portion of the Chesapeake Bight were examined and associated to real and environmental spaces. The sampling design was specifically intended to examine the small scale three dimensional structure of the Chesapeake Bay plume as characterized by its phytoplankton populations. The phytoplankton were sampled at 101 stations, non-synoptically, over a five day period in mid-June, 1980.

Several multivariate numerical techniques were used to determine the relationships between the phytoplankton species distributions and pattern the low salinity plume distribution. A pattern of distribution which approximated the salinity plume resulted from several clustering procedures. Environmental …

The Effects Of Copper On Skeletonema Costatum (Greville) Cleve, Susanne Sybille Jackman

Biological Sciences Theses & Dissertations

Copper levels and dominant phytoplankton species composition were examined from six sites in Kings Creek on Virginia's Eastern Shore from March to August 1980. Creek copper levels were determined by an APDCMIBK extraction procedure and ranged from 0.003 to 0.020 mg/1. Diatoms were the dominant phytoplankters with Skeletonema costatum (Greville) Cleve emerging as a major late summer species.

Subsequent laboratory studies involved 96-hour experiments using Skeletonema costatum (clone Skel) grown in enriched natural seawater. The water was collected from Kings Creek and enriched to Guillard and Ryther's (1962) f/2 media levels. Cupric sulfate was added to the experimental culture media …

The Seasonality Of Occurrence Of Larval And Juvenile Sciaenids In A Virginia Seaside Estuary, James Howard Cowan Jr.

Biological Sciences Theses & Dissertations

The seasonality of occurrence and relative abundance of larval and juvenile fishes, particularly members of the family Sciaenidae, from a Virginia seaside estuary were determined from ichthyoplankton and trawl collections made from March 1979 to March 1980.

The larvae of 20 species distributed among 15 families were identified from the ichthyoplankton. Larvae of the bay anchovy, Anchoa mitchilli, and the Atlantic silverside, Menidia menidia, dominated the samples and made up 57 and 34%, respectively, of all larvae collected. Peak occurrence began in May and continued through August. Fish larvae were present in the study area all year.

Twenty-eight …

Macrobenthic Communities Of An Industrialized Seaport Ecosystem: The Southern Branch Of The Elizabeth River, Virginia, Steven D. Hawthorne

Biological Sciences Theses & Dissertations

Macrobenthic invertebrates of an industrialized seaport ecosystem were studied seasonally from October, 1977 through July, 1978. Five stations were selected along the Southern Branch of the Elizabeth River, Virginia. The stations ranged from an area of heavy industrialization to a non-urbanized environment. At each station, bottom water was measured for salinity, temperature, dissolved oxygen, and pH. Within each sampling area, macrobenthic infauna! invertebrates were collected from in and out of channel sites along with sediment samples for various types of physicochemical analysis.

Community structure was spatially homogeneous at station sites and throughout the stations along the River. Slightly acidic pH …

Morphological Variation Among 14 Species Of Callogobius Bleeker (Pisces: Gobiidae), James Francis Mckinney

Biological Sciences Theses & Dissertations

A survey of the variation among the species of the Callogobius complex has been accomplished in order to determine if recognition of more than one genus is warranted for this assemblage of species. Emphasis has been placed on the osteological variation. Relationships among certain species within the Callogobius complex have been exposed. Although there are two well defined species groups within the complex, it is felt that inclusion of all of the examined species within the single genus Callogobius is the most parsimonious course of action.

Structure Of A Subtidal Benthic Community Near Cape Charles, Virginia, R. Michael Ewing

Biological Sciences Theses & Dissertations

Species composition, distribution, and abundance of benthic invertebrates of a subtidal community were examined at a location on the lower Delmarva Peninsula near Cape Charles, Virginia. Macrobenthos was sampled quarterly between June, 1977 and June, 1978 at nine sites along a transect in Old Plantation Creek and the adjacent offshore area. Spatial and temporal patterns of numerically important species are discussed.

Sampling sites and species were grouped by a numerical classification strategy which consisted of the Bray-Curtis similarity measure and group-average clustering. Three faunal assemblages were identified with the aid of constancy and fidelity nodal analyses: (1) a tidal creek …

The Spatial And Temporal Distribution Of Fish Eggs And Larvae In Hempstead Bay Estuary, Joseph Adelard Lessard

OES Theses and Dissertations

The ichthyoplankton of Hempstead Bay estuary was sampled from December 1972 to mid March 1974. Eleven stations were sampled by towing a 0.5 meter diameter plankton net. Eggs were most abundant during June and July with an average concentration calculated to be above 5,500/100m³. Egg densities were the lowest during the fall and winter. Larvae were most frequently taken from March through July with densities varying greatly among the samples. The eggs of Brevoortia tyrannus, Anchoa mitchilli, Tautoga onitis, Tautogolabrus adspersus, and Scophthalmus aguosus and the larvae of Menidia menidia, Ammodvtes hexapterus and Pseudopleuronectes americanus constituted most …

Animal-Sediment Relationship Study Of The Western Branch Of The Lynnhaven River, Charles Perry Seymour

Biological Sciences Theses & Dissertations

The animal-sediment relationships of the marine benthic infauna of an estuarine river system, Lynnhaven River, Virginia Beach, Virginia, were studied at six sites, sampled bimonthly for one year. Six species were found to dominate all of the sampling periods and sites for the year. The greatest number of individuals, biomass, and species were found at the sand sites. Deposit feeders were recorded in greater number than suspension feeders at both the sand and the mud sites.

Cluster and nodal analyses were successful in demonstrating animal-sediment relationships for the intertidal regions of the river system.

Contributions To The Reproductive Biology And Natural History Of The Pirateperch, Aphredoderus Sayanus, Edward O. Murdy

Biological Sciences Theses & Dissertations

The purpose of this study was to describe the micro and macro-anatomy of the reproductive system and the testicular and ovarian development in Aphredoderus sayanus.

Specimens were collected at least once a month from September, 1976, through May, 1977, in Cypress Pond, a part of the Dismal Swamp drainage, outside of Suffolk, Virginia. Forty-three specimens had their gonads examined histologically, of these 13 were males, 29 were females and in one specimen the sex was not determinable.

Aphredoderus sayanus is a spring spawner, spent gonads were found on and after April 13, 1977. Gonads began to ripen in the …

An Intensive Study Of The Spring Phytoplankton Bloom In Lynnhaven Bay, Virginia, Donald Lynn Webster

Biological Sciences Theses & Dissertations

Phytoplankton samples were collected biweekly from two stations, one in each branch of Lynnhaven Bay, Virginia over the period January 24 to June 9, 1975. Water temperature, salinity, pH, oxygen, ammonia, urea, reactive nitrite, reactive nitrate, reactive phosphorus, productivity, transparency, and weather conditions were recorded concurrently. Data were manipulated employing analysis of variance, simple correlation, correlation matrices, and forward stepwise multiple regression. Total phytoplankton numbers exhibited a unimodal pattern. A pre-bloom pulse was recorded at both stations in late February. The spring bloom lasted from April through May. Phytoplankton growth was primarily a function of nutrient supply and temperature. Nutrient …

The Distribution Of Submersed Hydrophytes In Currituck Sound, Steven Harry Davis

Biological Sciences Theses & Dissertations

The rooted submergent flora of Currituck Sound, North Carolina was determined, and the distributions of its species investigated with respect to salinity, substrate texture, depth, pH, turbidity and species co-occurrence. Eight species of hydrophytes were found: Potamogeton pectinatus, Fotamogeton perfoliatus, Ruppia maritima, Zannichellia palustris, Najas guadalupensis, Elodea nuttallii, Vallisneria americana, and Myriophyllum spicatum. The mean salinities at which each species occurred ranged from 1.0 ppt for E. nuttallii to 3.1 ppt for Z. palustris, Ruppia maritima, Z palustris and V. americana were the only species that commonly occurred on coarse-grained substrates. Elodea nuttallii and N. guadalupensis …

Seasonal Distribution Of Higher Marine And Aquatic Fungi In The Back Bay National Wildlife Refuge, Scott Schatz

Biological Sciences Theses & Dissertations

Abstract unavailable.

Microbenthic Algal Production Of An Intertidal Sandflat In Little Creek Harbor, Virginia Beach, Virginia, Clayton Barry Shedrow

OES Theses and Dissertations

Estimated annual net microbenthic algal production of an intertidal sandflat on Little Creek Inlet, Virginia Beach, Virginia, was 105 g C/m². Seasonally, primary production was greatest during the summer and fall periods (38 and 49 g C/m², respectively). Productivity was found to vary directly with water temperature and standing crop of benthic diatoms, and inversely with incident solar radiation and standing crops of sedimentary chlorophyll 'a' and 'c'. Orthophosphate and nitrate-N appeared to be limiting factors, nitrate-N more so than orthophosphate. Mean annual net photosynthetic efficiency (based upon total light) for the microphytobenthic community was 0.09%. …

Osteology Of Trypauchenichthys Sumatrensis Hardenburg, Christine Parrish Baer

Biological Sciences Theses & Dissertations

The osteology of a Malaysian goby was examined in detail and compared to other gobioids. Results indicated that Trypauaheniahthys sumatrensis is a specialized, but definite member of the Gobioidei. Some osteological characteristics of a related fish, Trypauchen vagina, were also discussed.

Observations On The Distribution And Composition Of Zooplankton In Portions Of The Intracoastal Waterway, Virginia, O. Clair Hillard Jr.

Biological Sciences Theses & Dissertations

Five stations were established in the Southern Branch of the Elizabeth River, the Dismal Swamp Canal, the Albemarle and Chesapeake Canal and the North Landing River. Representative samples of zooplankton were taken from October 1971 to June 1972. A. total of 57 species were identified and discussions regarding seasonal distribution in relation to physical factors and circulation are presented.

The composition of the zooplankton was found to fluctuate greatly due to the variables characteristic of the study area. The combined effect of tidal flow with freshwater input in conjunction with drainage from the Great Dismal Swamp, results in isolated populations …

Seasonal Composition Of Zooplankton Of Lower Chesapeake Bay And Virginia Coastal Waters, Elizabeth W. Atkinson

Biological Sciences Theses & Dissertations

Abstract unavailable.

Phytoplankton Distribution In Waters Off The Northeastern Coast Of The United States, Sharon H. Craft

Biological Sciences Theses & Dissertations

Abstract unavailable.