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Articles 1 - 16 of 16

Full-Text Articles in Life Sciences

Discocilia And Paddle Cilia In The Larvae Of Mulinia Lateralis And Spisula Solidissima (Mollusca: Bivalvia), Bernardita Campos, Roger L. Mann Dec 1988

Discocilia And Paddle Cilia In The Larvae Of Mulinia Lateralis And Spisula Solidissima (Mollusca: Bivalvia), Bernardita Campos, Roger L. Mann

VIMS Articles

The bivalve larval velum contains four bands of cilia: inner and outer preoral bands, an adoral band, and a postoral band. The preoral bands of compound cilia are generally considered to be used for both locomotion and food gathering. The adoral and postoral bands function in concert with the preoral bands in food gathering and transfer of food to the mouth. Cilia are usually described as cylindrical structures which taper to a blunt tip. Modified cilia with disc-shaped (discocilia) or pad dle-shaped ends have been recorded in several invertebrate species. Here, for the first time, we demonstrate the presence of ...


Survival Of Escherichia-Coli And Salmonella Spp In Estuarine Environments, Mw Rhodes, Hi Kator Dec 1988

Survival Of Escherichia-Coli And Salmonella Spp In Estuarine Environments, Mw Rhodes, Hi Kator

VIMS Articles

Survival of Escherichia coli and Salmonella spp. in estuarine waters was compared over a variety of seasonal temperatures during in situ exposure in diffusion chambers. Sublethal stress was measured by both selective-versus-resuscitative enumeration procedures and an electrochemical detection method. E. coli and Salmonella spp. test suspensions, prepared to minimize sublethal injury, were exposed in a shallow tidal creek and at a site 7.1 km further downriver. Bacterial die-off and sublethal stress in filtered estuarine water were inversely related to water temperature. Salmonella spp. populations exhibited significantly less die-off and stress than did E. coli at water temperatures of <10°C. Although the most pronounced reductions (ca. 3 log units) in test bacteria occurred during seasonally warm temperatures in the presence of the autochthonous microbiota, 102 to 104 test cells per ml remained after 2 weeks of exposure to temperatures of >15 ...


Distribution And Abundance Of The Bottlenose Dolphin, Tursiops-Truncatus (Montagu, 1821), In Virginia, Robert A. Blaylock Jan 1988

Distribution And Abundance Of The Bottlenose Dolphin, Tursiops-Truncatus (Montagu, 1821), In Virginia, Robert A. Blaylock

VIMS Articles

No abstract provided.


A Limited Information Approach For Determining Capital Stock And Investment In A Fishery, James E. Kirkley, Dale E. Squires Jan 1988

A Limited Information Approach For Determining Capital Stock And Investment In A Fishery, James E. Kirkley, Dale E. Squires

VIMS Articles

No abstract provided.


Seasonal Abundance Of Oyster Spat And Four Animal Associates On An Oyster Reef In The James River, Virginia, Reinaldo Morales-Alamo, Carrollyn Cox, Kevin J. Mccarthy, Roger L. Mann Jan 1988

Seasonal Abundance Of Oyster Spat And Four Animal Associates On An Oyster Reef In The James River, Virginia, Reinaldo Morales-Alamo, Carrollyn Cox, Kevin J. Mccarthy, Roger L. Mann

VIMS Articles

Five species of invertebrates collected at bi-weekly to monthly intervals from an oyster reef in the James River, Virginia. between September 1984 and August 1985 exhibited similar patterns of fluctuation in abundance throughout most of the period. The species were: spat of the oyster Crassostrea virginica: two species that feed on oysters. the flatworm Stylochus ellipticus, and the gastropod Boonea impressa. as well as two others with no known direct trophic interactions with the oyster. the isopod Cassidinidea lunifrons and the nudibranch Doridella obscura. B. impressa was many times more abundant than S. ellipticus but because of the difference in ...


A Comparison Of Paraffin Histology And Hemolymph Analysis For The Diagnosis Of Haplosporidium Nelsoni (Msx) In Crassostrea Virginica (Gmelin), Eugene M. Burreson, M.Elizabeth Robinson, Antonio Villalba Jan 1988

A Comparison Of Paraffin Histology And Hemolymph Analysis For The Diagnosis Of Haplosporidium Nelsoni (Msx) In Crassostrea Virginica (Gmelin), Eugene M. Burreson, M.Elizabeth Robinson, Antonio Villalba

VIMS Articles

Diagnosis of the oyster pathogen Haplosporidium nelsoni (MSX) by paraffin histology is compared with a technique in which hemolymph drawn from the oyster adductor muscle sinus is examined for parasite plasmodia. Oysters from seed beds of the James River, Virginia imported to an MSX endemic area in May, 1986 were sampled monthly through December, 1986 and in February, 1987. A sample of 25 oysters was bled each month and then processed for sectioning. Of the 200 oysters sampled, 89 (44.5%) were diagnosed as infected using histology and 61 (30.5%) were diagnosed as infected using hemolymph examination. All the ...


Development And Evaluation Of Techniques To Study Acquired Immunity To Perkinsus Marinus In The Oyster, Crassostrea Virginica (Gmelin), Fu-Lin Chu Jan 1988

Development And Evaluation Of Techniques To Study Acquired Immunity To Perkinsus Marinus In The Oyster, Crassostrea Virginica (Gmelin), Fu-Lin Chu

VIMS Articles

This paper describes a radiometric technique developed to measure phagocytosis of Perkinsus marinus zoospores by oyster hemocytes. The spores of P. marinus were radiolabeled by culturing P. marinus presporangia and sporangia in estuarine water (22%o) containing 14C-glycine. The percent of spores phagocytized by hemocytes was determined by the uptake of radioactivity by hemocytes.

Results from preliminary experiments to test the efficiency of using an osmotic infiltration method for immunizing oysters are also reported. It was found that oysters can take up both dissolved antigen (radiolabeled bovine serum albumin) and particulate antigen ( 14C-labeled zoospore homogenate) through osmotic infiltration. The uptake ...


Field Studies Of Bivalve Larvae And Their Recruitment To The Benthos: A Commentary, Roger L. Mann Jan 1988

Field Studies Of Bivalve Larvae And Their Recruitment To The Benthos: A Commentary, Roger L. Mann

VIMS Articles

A list of factors influencing the recruitment of bivalve larvae might include, but not be limited to, the following: egg quality, physical environment, food availability, loss to predation and disease during larval development, interplay of passive dispersal (horizontally) by water currents and depth regulation by active swimming, proximity of suitable and available substratum as metamorphic competency is achieved, and availability of sufficient metabolic reserves to complete metamorphosis to the benthic form. While tractable methods exist to quantify aspects of certain members of the above list, the focus of such work has usually been biased towards laboratory experiments or hatchery production ...


Distribution Of Bivalve Larvae At A Frontal System In The James River, Virginia, Roger L. Mann Jan 1988

Distribution Of Bivalve Larvae At A Frontal System In The James River, Virginia, Roger L. Mann

VIMS Articles

James River is the southernmost of the major subestuaries of the Chesapeake Bay, USA. A frontal system develops on the early flood tide in the Hampton Roads region of the lower James. This system, together with a cyclonic gyre in Hampton Roads, is in part responsible for partial retention of downstream-flowing water in the estuary and it's injection into deeper, upstream-flowing water. The role of the frontal system in retention of bivalve larvae in the James was investigated In a 2-part study: a field exammation of larval distr~bution versus depth along a transect across the front in relation ...


Synchronous Emergence And Mass Migration In Juvenile Queen Conch, Aw Stoner, Rom Lipcius, Ls Marshall, At Bardales Jan 1988

Synchronous Emergence And Mass Migration In Juvenile Queen Conch, Aw Stoner, Rom Lipcius, Ls Marshall, At Bardales

VIMS Articles

No abstract provided.


Pipefish Foraging: Effects Of Fish Size, Prey Size And Altered Habitat Complexity, Ch Ryer Jan 1988

Pipefish Foraging: Effects Of Fish Size, Prey Size And Altered Habitat Complexity, Ch Ryer

VIMS Articles

Laboratory experiments determined the effects of 2 levels of habitat complexity upon pipefish Syngnathus fuscus foraging for amphipods. Habitats were composed of equal densities of either narrow (low complexity) or wide (high complexity) leafed artificial seagrass. Response to habitat - as measured by rate of encounter with amphipods, probability of attack after encounter, probability of success after attack, and overall rate of amphipod consumption - was determined for combinations of 2 fish size classes and 3 amphipod size classes. Small fish did not respond to changes in habitat complexity, while large fish did. Large fish encountered fewer amphipods in the high than ...


Nearshore Ichthyoplankton Associated With Seagrass Beds In The Lower Chesapeake Bay, Je Olney, Gw Boehlert Jan 1988

Nearshore Ichthyoplankton Associated With Seagrass Beds In The Lower Chesapeake Bay, Je Olney, Gw Boehlert

VIMS Articles

Estuaries serve as important nursery habitats for larvae and juveniles of many species of fishes and invertebrates. Within the estuary, however, partitioning may occur among main channel. mud flat, tidal creek, and vegetated habitats. In this study we describe the egg, larval, and juvenile fish assemblages in shallow areas of submerged aquatic vegetation (SAV) of the lower Chesapeake Bay and compare them with those over the adjacent, shallow sand habitat. Densities at night over all habitats were about 1 order of magnitude higher than daytime densities, and were highest in summer. The SAV habitats were not important spawning sites for ...


Subsurface Chlorophyll Maximum In August-September 1985 In The Climax Area Of The North Pacific, Rw Eppley, E Swift, Dg Redalje, Mr Landry, Lw Haas Jan 1988

Subsurface Chlorophyll Maximum In August-September 1985 In The Climax Area Of The North Pacific, Rw Eppley, E Swift, Dg Redalje, Mr Landry, Lw Haas

VIMS Articles

No abstract provided.


Rehabilitation Of The Troubled Oyster Industry Of The Lower Chesapeake Bay, William J. Hargis Jr., Dexter S. Haven Jan 1988

Rehabilitation Of The Troubled Oyster Industry Of The Lower Chesapeake Bay, William J. Hargis Jr., Dexter S. Haven

VIMS Articles

After 1885 Virginia's lower Chesapeake Bay system produced more oysters per year than any other area in the United States and remained predominant until 1960. Since then she has surrendered supremacy as annual harvests of her troubled oyster industry have steadily declined. Numerous factors were responsible for the tremendous productivity of the lower Bay's oyster beds; a number have been involved in its decline. Natural events, such as the catastrophic epizootics of the early 1960's, continuing disease and predation, increased salinities of drought years and great freshets of tropical storms have contributed significantly to the reduction. Pollution ...


Fishery And Culture Of Selected Bivalves In Mexico: Past, Present And Future, Erik Baqueiro, Michael Castagna Jan 1988

Fishery And Culture Of Selected Bivalves In Mexico: Past, Present And Future, Erik Baqueiro, Michael Castagna

VIMS Articles

This paper reviews the culture of selected bivalves of Mexico. Most species are utilized locally, but there is potential for some exports. The culture and fisheries of bivalves are often hampered by lack of information and restrictive regulations. Pinctada mazatlanica was grown for pearls and pearl shell production in the early 1900s. The methods used for its culture are reviewed. The culture of a few commercial species has shown encouraging results. Over 10,000 kilometers of coastal area with more than 1.5 million hectares of coastal lagoons and bays, plus a subtropical climate, give Mexico a great potential for ...


Chemotactic Response Of Fish Macrophages To Legionella-Pneumophila - Correlation With Pathogenicity, Ba Weeks, Sr Sommer, Hp Dalton Jan 1988

Chemotactic Response Of Fish Macrophages To Legionella-Pneumophila - Correlation With Pathogenicity, Ba Weeks, Sr Sommer, Hp Dalton

VIMS Articles

Chemotaxis is the directional migration of cells in response to a chemical stimulus. This phenomenon appears to be responsible for the accumulation of macrophages during inflammation This work represents an attempt to understand certain aspects of host-parasite relationships in Legionnaire's Disease. In the first phase of this study, we measured the chemotactic stimulation of fish macrophages by 2 strains of Legionella pneumophila, one virulent and one avirulent for guinea pigs. Results from this part of the study, coupled with the possibility that reduced chemotaxis may be a factor contributing to increased virulence, led us to initiate the second phase ...