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Full-Text Articles in Life Sciences
Organic Carbon Partitioning During Spring Phytoplankton Blooms In The Ross Sea Polynya And The Sargasso Sea, C.A. Carlson, Hugh Ducklow, Da Hansell, Walker O. Smith Jr.
Organic Carbon Partitioning During Spring Phytoplankton Blooms In The Ross Sea Polynya And The Sargasso Sea, C.A. Carlson, Hugh Ducklow, Da Hansell, Walker O. Smith Jr.
VIMS Articles
In this study we evaluate the partitioning of organic carbon between the particulate and dissolved pools during spring phytoplankton blooms in the Ross Sea, Antarctica, and the Sargasso Sea. As part of a multidisciplinary project in the Ross Sea polynya we investigated the dynamics of the dissolved organic carbon (DOC) pool and the role it played in the carbon cycle during the 1994 spring phytoplankton bloom. Phytoplankton biomass during the bloom was dominated by an Antarctic Phaeocystis sp. We determined primary productivity (PP; via H14CO3, incubations), particulate organic carbon (POC), bacterial productivity (BP; via [3H]thymidine incorporation), and DOC during two …
On The Frequency Of Eusociality In Snapping Shrimps (Decapoda : Alpheidae), With Description Of A Second Eusocial Species, Je Duffy
VIMS Articles
Recently, the Caribbean snapping shrimp Synalpheus regalis was shown to be eusocial by the criteria historically used for honeybees, ants, and termites, i.e., colonies contain a single reproducing female and a large number of non-breeding "workers." This finding prompted a reexamination of several previously puzzling reports of unusual population structures in other Synalpheus species. New collections, and observations made by students of this genus over the last century, suggest that several sponge-dwelling Synalpheus species similarly exhibit overlapping generations and monopolization of reproduction by a few individuals, and thus that these species may also be eusocial according to classical entomological criteria. …
Response Of Settling Oyster Larvae, Crassostrea Virginica, To Specific Portions Of The Visible Light Spectrum, Patrick Baker, Roger L. Mann
Response Of Settling Oyster Larvae, Crassostrea Virginica, To Specific Portions Of The Visible Light Spectrum, Patrick Baker, Roger L. Mann
VIMS Articles
Settlement site choice was used to rest the ability of competent-to-settle oyster (Crassostrea virginica) larvae to detect specific portions of the visible light spectrum. Larvae were permitted to settle on illuminated or shaded sides of vertically oriented settlement substrates. Five light treatments were used, including white light (400-700 nm), three fractions of white light; red light (600-700 nm), green light (450-575 nm, peak at 525 nm), blue light (400-500 nm, peal; at 425 nm); and total darkness. In total darkness, no settlement preference for either side of the substrates was detected. In all light treatments, larvae settled in significantly higher …
Predation On Postlarvae And Juveniles Of The Shore Crab Carcinus Maenas: Importance Of Shelter, Size And Cannibalism, Po Moksnes, L Pihl, J Van Montfrans
Predation On Postlarvae And Juveniles Of The Shore Crab Carcinus Maenas: Importance Of Shelter, Size And Cannibalism, Po Moksnes, L Pihl, J Van Montfrans
VIMS Articles
Settlement and early juvenile stages are considered a bottleneck in the Life history of many epibenthic organisms because of high predation mortality. Nursery habitats may play an important role in mitigating settlement and post-settlement mortality by providing refuge from predation. We examined these relationships in postlarvae and early juvenile stages of the shore crab Carcinus maenas L. in laboratory and field tethering experiments. We studied habitat and size related habitat mortality using postlarvae and young juvenile crabs as prey, and various predators, including juvenile conspecifics, in several habitats common in shallow (0 to 1 m) soft bottom nursery areas on …
Application Of Molecular Genetic Markers To Conservation Of Freshwater Bivalves, Margaret Mulvey, Hsiu-Ping Liu, Karen Kandl
Application Of Molecular Genetic Markers To Conservation Of Freshwater Bivalves, Margaret Mulvey, Hsiu-Ping Liu, Karen Kandl
VIMS Articles
Freshwater bivalves (Unionacea) are among the most endangered faunal elements in North America. Molecular genetic studies have much to offer conservation efforts directed to this declining fauna. Molecular genetic data can provide information needed to identify evolutionarily significant units, resolve taxonomic ambiguities, describe population structure, evaluate impacts of habitat fragmentation and reduced gene flow among populations, reconstruct phylogenetic relationships, clarify fish host-glochidia relationships, and provide evidence in legal actions. Molecular genetic techniques and their application to freshwater bivalves are reviewed.
Novel Optical Remote Sensing And Ground-Truthing Of Benthic Habitat Using The Burrow-Cutter-Diaz Plowing Sediment Profile Camera System (Bcd Sled), Gr Cutter Jr., Robert J. Diaz
Novel Optical Remote Sensing And Ground-Truthing Of Benthic Habitat Using The Burrow-Cutter-Diaz Plowing Sediment Profile Camera System (Bcd Sled), Gr Cutter Jr., Robert J. Diaz
VIMS Articles
The Jefferson Benthic Sled provides video sediment profile imagery of continuous cross-sectional data. Subsurface imaging is achieved by attaching a profile camera prism behind an agricultural plow that extends beneath the plane of the sled skids, slicing through the top 10 to 20 cm of sediment. The plowing video profile provides a high-resolution, real-time: remotely controlled view of the flat side of the plow furrow. Successful continuous profiles of up to 100 m have been collected. The equipment allows immediate characterization of benthic habitats, transition zones, sediment types, sediment oxidation layering, biological resources, and fisheries impact.
Effects Of Periodic Environmental Hypoxia On Predation Of A Tethered Polychaete, Glycera Americana: Implications For Trophic Dynamics, Ja Nestlerode, R. J. Diaz
Effects Of Periodic Environmental Hypoxia On Predation Of A Tethered Polychaete, Glycera Americana: Implications For Trophic Dynamics, Ja Nestlerode, R. J. Diaz
VIMS Articles
Hypoxia and anoxia have significant deleterious ecological effects on living resources throughout many estuarine and marine ecosystems worldwide. Brief periods of low oxygen have the potential to facilitate transfer of benthic production to higher trophic levels as many benthic infaunal species have shallower sediment depth distributions during hypoxic events. In August-September 1994, a time-lapse camera equipped with a water quality datalogger was used to document in situ exploitation of a tethered prey organism (Glycera americana Leidy) by mobile fish and crustacean predators during alternating normoxia-hypoxia cycles in the York River, Virginia, USA. Based on photographic and diver observations, this hypoxia-induced …
Growth Dynamics Of Phaeocystis Antarctica-Dominated Plankton Assemblages From The Ross Sea, Walker O. Smith Jr., Ca Carlson, Hw Ducklow, Da Hansell
Growth Dynamics Of Phaeocystis Antarctica-Dominated Plankton Assemblages From The Ross Sea, Walker O. Smith Jr., Ca Carlson, Hw Ducklow, Da Hansell
VIMS Articles
Large-volume experiments were conducted using natural seawater assemblages collected in the southern Ross Sea during austral spring 1994 and summer 1995 to assess the carbon and nitrogen exchanges among phytoplankton, bacteria and dissolved organic carbon pools, and to compare the elemental partitioning in these experimental enclosures with those observed in situ. Large concentrations of particulate matter were produced in these enclosures, which were at all times dominated by the colonial haptophyte Phaeocystis antarctica. Particulate organic carbon concentrations exceeded 200 mu mol l(-1) at the end of the experiment. Bacterial carbon comprised only a small (%) fraction of the particulate carbon, …
Observations Of A Protistan Disease Similar To Qpx In Mercenaria Mercenaria (Hard Clams) From The Coast Of Massachusetts, Roxanna Smolowitz,, Dale Leavit, Frank Perkins
Observations Of A Protistan Disease Similar To Qpx In Mercenaria Mercenaria (Hard Clams) From The Coast Of Massachusetts, Roxanna Smolowitz,, Dale Leavit, Frank Perkins
VIMS Articles
During the summer and fall of 1995, in clam aquaculture leases at two locations on the coast of Massachusetts, significant mortalities were observed to occur primarily in 112" role="presentation" style="font-size: 0.9px; display: inline-block; position: relative;">- to 2-year old hard clams (Mercenaria mercenaria,quahog) planted in the leases. Examination of hard clams from those leases suggested a parasite similar to QPX (Quahog Parasite Unknown), as described by Whyte, S. K., Cawthorn, R. J., and McGladdery, S. E. (1994,Can. Dis. Ag. Org.19, 129–136), was responsible for the poor condition of affected clams and the resulting high mortality. In …