Life Sciences Commons^™

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 …

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 the development …

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 and other man-related …

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 heavy and …

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. …

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 of …

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

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

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 …

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 …