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JOURNAL OF SHELLFISH RESEARCH
IVOLUME 30, NUMBER 2
AUGUST 2011
I
iVational Shellfisheries Association, Baltimore, Maryland
cultured products all suggest that blue crab aquaculture for softshell
and bait production would be an economically viable enterprise.
Use of hatchery-reared blue crabs would allow for fishery development independent of Mid stocks.
"OILY" DROPLETS ASSOCIATED WITH BLUE CRAB
MEGALOPAE COLLECTED IN THE NORTHERN GULF
OF MEXICO
Harriet Perry \ Thomas VanDevender 1, Robert Trigg 1, Amy
Meyers 2
1
Gulf Coast Research Laboratory, 703 East Beach Drive, Ocean
Springs, MS, 39564, USA.
2
McSwain Engineering, Inc., 3320 McLemore Drive, Pensacola,
FL, USA.
The blue crab, Callinectes sapidus, has planktotrophic larval
development with seven zoeal molts and the metamorphic molt to
the megalopal (postlarval) stage occurring in offshore waters. The
Deepwater Horizon oil spill coincided with the spawning of blue
crabs in the northern Gulf of Mexico and movement of megalopae
from offshore waters to inshore estuarine environments. Blue crab
megalopae, along with early life history stages of other invertebrates, were sampled on passive collectors positioned along the
coastline. Megalopae collected in May in Louisiana waters contained unusual "oily-appearing" droplets wedged between the
exoskeleton of the cephalothorax and the inne~ integument. These
droplets were not observed in blue crab megalopae during eleven
years of extensive monitoring of blue crab early life history stages
by personnel of the Gulf Coast Research Laboratory. Additional
collections of blue crab megalopae from Florida to Louisiana and
larvaefpostlarvae of other brachyuran crabs, polychaetes, and
barnacles also contained similar droplets. Analyses are being
conducted to determine the precise composition and origin of the
droplets using an open-beam mass spectrometer (JEOL AccuTOFTh< DART® Direct Analysis in Real Time with Time-of-Flight
Mass Spectrometer). Results of these analyses will be discussed.
\
OYSTER RESPONSES TO THE DEEPWATER HORIZON
OIL SPILL ACROSS COASTAL LOUISIANA: EXAMINING
OYSTER HEALTH AND HYDROCARBON BIO-ACCUMULATJON.
Jerome La Peyre 1, Sandra Casas 1, Scott Miles 2 •
1
Louisiana State University Agricultural Center, Baton Rouge,
LA. 70803, USA.
2
Louisiana State University, Baton Rouge, LA, 70803, USA.
The eastern oyster ( Crassostrea virginica) is a major component
of the Gulf Coast seafood industry, especially in Louisiana, and is
also a vital constituent of estuarine environments. Polynuclear
aromatic hydrocarbons (PAHs) present in oil pose a risk to filterfeeding bivalves such as oysters, which can effectively take up and
accumulate these toxic substances. PAHs can have a wide range of
deleterious effects on oysters from sub-lethal effects that include
Abstracts, 103rct Annual Meeting, March 27-31, 2011
543
reductions in growth, impaired immunocompetence, increased
susceptibility to dermo disease caused by the oyster pathogen
Perkinsus marinus, decreased reproductive capability, to death. To
assess the consequences of the Deepwater Horizon oil spill on oyster
populations in Louisiana, the overall health and PAH concentrations of caged and wild oysters sampled pre-spill and at 3 and 9
months after oil exposure are being assessed. Specifically, using a
number of biomarkers we are conducting a spatial and seasonal
investigation of the oysters' health, nutritional, reproductive and
immunological status in relation to their body total hydrocarbon
and PAHs concentrations in oiled and non-oiled sites. This work is
funded by the Louisiana Sea Grant College Program.
MATRIX METALLOPROTEINASES AND HEMOCYTE
MIGRATION IN THE EASTERN OYSTER, CRASSOSTREA
VIRGIN/CA.
Jessica L. Piesz, Marta GOmez-Chiarri.
University of Rhode Island, 120 Flagg Rd, CBLS 170, Kingston,
RI, 02881, USA.
The mechanisms governing hemocyte migration in invertebrate
defense are poorly understood. In mammals, migration is mediated
by a family of zinc-dependent pro teases called matrix metalloproteinases (MMPs). These pro teases .break down components of the
extracellular matrix allowing cells to migrate through tissues. One
MMP, CvlMMP, has been identified to be upregulated in hemocytes of the Eastern oyster and is localized at the leading edge of
migration in cells migrating through digestive tissues during
feeding. These findings suggest that CvlMMP may play a role in
hemocyte migration. The effect of the metalloproteinase inhibitor
GM600 1 on hemocyte migration in response to immune stimuli like
zymosan A from Saccharomyces cerevisiae and heat-killed and live
Vibrio tubiashii isolate RE22 was tested using a,96-well chemotaxis
chamber. Data showed there were a differential response in the
migration of hyalinocytes and granulocytes to zymosan A and
RE22, with hyalinocytes preferentially migrating in response to
zymosan A and granulocytes preferentially responding to bacterial
products. The migration of hemocytes pre-treated with GM6001
was reduced compared to controls. These results suggest that
matrix metalloproteinases are involved in hemocyte migration in
oysters. This research provides valuable insight into oyster immunity that could aid in developing str8.tegies to manage disease.
GENOME-WIDE ANALYSIS OF INBREEDING DEPRESSION IN THE PACIFIC OYSTER CRASSOSTREA GIGAS,
USING A QTL MAPPING APPROACH.
Louis Plough, Dennis Hedgecock.
University of Southern California, 3616 Trousdale Parkway, AHF
107, Los Angeles, CA, 90089, USA.
Discovery of a large number o'f deleterious recessive mutations
(genetic load) in ihe Pacific oyster explains distorted segregation
ratios, seen widely in bivalves, and supports the dominance theory