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Old Dominion University

Biological Sciences Faculty Publications

1999

Articles 1 - 7 of 7

Full-Text Articles in Life Sciences

Adaptive Strategies That Reduce Predation On Caribbean Spiny Lobster Postlarvae During Onshore Transport, Charles A. Acosta, Mark J. Butler Iv May 1999

Adaptive Strategies That Reduce Predation On Caribbean Spiny Lobster Postlarvae During Onshore Transport, Charles A. Acosta, Mark J. Butler Iv

Biological Sciences Faculty Publications

Like many marine species with meroplanktonic larvae, the Caribbean spiny lobster (Panulirus argus) has a postlarval stage that moves from the oceanic plankton to inshore nurseries only under specific environmental conditions (i.e., at night, in the surface water layer, on the flood tide, and during new moon), presumably to avoid predation or to enhance onshore transport. Using held and mesocosm experiments, we compared predation on planktonic postlarvae swimming at night near the surface and bottom over coastal habitats along typical offshore-inshore transport paths and determined whether predation rates differed between lunar periods (new moon vs, full moon) and with prey …

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The Cause And Consequence Of Ontogenetic Changes In Social Aggregation In New Zealand Spiny Lobsters, Mark J. Butler Iv, Alistair B. Macdiarmid, John D. Booth Jan 1999

The Cause And Consequence Of Ontogenetic Changes In Social Aggregation In New Zealand Spiny Lobsters, Mark J. Butler Iv, Alistair B. Macdiarmid, John D. Booth

Biological Sciences Faculty Publications

Ontogenetic changes in the behavior, spatial distribution, or habitat use of a species are presumably adaptations to ecological forces that differ in their effect on various life stages. The New Zealand rock lobster Jasus edwardsii is one of several species of spiny lobster that exhibits dramatic ontogenetic shifts in sociality and spatial distribution, and we tested whether such changes are adaptive. We first surveyed several natural populations of J. edwardsii to document size-specific differences in aggregation. To determine if chemical cues discharged by conspecifics promote aggregation of certain ontogenetic stages, we tested the responsiveness of lobsters of 3 ontogenetic stages …

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Nucleotide Sequence Of The Streptococcin A-Ff22 Lantibiotic Regulon: Model For Production Of The Lantibiotic Sa-Ff22 By Strains Of Streptococcus Pyogenes, Robert E. Mclaughlin, Joseph J. Ferretti, Wayne L. Hynes Jan 1999

Nucleotide Sequence Of The Streptococcin A-Ff22 Lantibiotic Regulon: Model For Production Of The Lantibiotic Sa-Ff22 By Strains Of Streptococcus Pyogenes, Robert E. Mclaughlin, Joseph J. Ferretti, Wayne L. Hynes

Biological Sciences Faculty Publications

Streptococcin A-FF22 (SA-FF22) is a type AII linear lantibiotic produced by Streptococcus pyogenes strain FF22. Sequence analysis of an approximate 10 kb region of DNA showed it to contain nine open reading frames arranged in three operons responsible for regulation, biosynthesis and immunity of SA-FF22. This region is organized similarly to the Lactococcus lactis lacticin 481 region, however, unlike lacticin 481, a two-component regulatory system is essential for SA-FF22 production. located immediately downstream of the scn region is a putative transposase gene, the presence of which supports earlier data that indicated a mobile nature to this region. (©) 1999 Published …

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Growth And Feeding Studies On The Algal Feeding Stage Of A Pfiesteria-Like Dinoflagellate, David W. Seaborn, A. Michelle Seaborn, William M. Dunstan, Harold G. Marshall Jan 1999

Growth And Feeding Studies On The Algal Feeding Stage Of A Pfiesteria-Like Dinoflagellate, David W. Seaborn, A. Michelle Seaborn, William M. Dunstan, Harold G. Marshall

Biological Sciences Faculty Publications

The dinoflagellate Cryptoperidiniopsis sp. was isolated from sediment samples taken from Virginia estuaries, and established in culture for subsequent growth and feeding studies. The maximum abundance, or yield, of Cryptoperidiniopsis is exponentially related to the concentration of algal prey and is saturated at about 4.00 X 105 mL-1. Salinity from 10-20 ppt and temperature between 15-25 C have no effect on the yield of this form of Cryptoperidiniopsis. Light intensity has a secondary effect in that the algal prey reproduces more quickly in higher light as they are being grazed. Growth rates of Cryptoperidiniopsis were …

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Water Quality Relationships To Concentrations Of Pfiesteria-Like Organisms In Virginia Estuaries For 1998., Everett P. Weber, Harold G. Marshall Jan 1999

Water Quality Relationships To Concentrations Of Pfiesteria-Like Organisms In Virginia Estuaries For 1998., Everett P. Weber, Harold G. Marshall

Biological Sciences Faculty Publications

A series of statistical analyses were performed to identify the relationship between abundance of dinoflagellates grouped as Pfiesteria-like organisms and a set of 25 water quality variables from May through October of 1998 at 41 estuarine locations. Although regions were identified in relation to seasonal density of cells present, there were no strong relationships to specific water quality variables. Factors that may have influenced these results included: a) several species were included in the group analyzed and this composite did not respond as a unit to changing environmental conditions; b) cell concentrations were low and there were a large …

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Monitoring Results For Pfiesteria Piscidida And Pfiesteria-Like Organisms From Virginia Waters In 1998, Harold G. Marshall, David W. Seaborn, Jennifer Wolny Jan 1999

Monitoring Results For Pfiesteria Piscidida And Pfiesteria-Like Organisms From Virginia Waters In 1998, Harold G. Marshall, David W. Seaborn, Jennifer Wolny

Biological Sciences Faculty Publications

Results of an extensive 1998 monitoring program for the presence of Pfiesteria-like organisms (PLO) in Virginia estuaries indicate these dinoflagellates are widely distributed in both the water column, and as cysts in the sediment, however Pfiesteria piscicida was not detected at this time. The highest concentrations of PLO were in estuaries along the Virginia shore line of the Potomac River, and in western Chesapeake Bay estuaries from the Little Wicomico River to the Rappahannock River. The most common PLO included Cryptoperidiniopsis sp. and Gymnodinium galatheanum. The lowest PLO concentrations were at ocean side locations. PLO were also …

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Pfiesteria Piscicida And Dinoflagellates Similar To Pfiesteria, Harold G. Marshall Jan 1999

Pfiesteria Piscicida And Dinoflagellates Similar To Pfiesteria, Harold G. Marshall

Biological Sciences Faculty Publications

Pfiesteria pisiccida is a microscopic, unicellular organism that is classified as both a mixotrophic and heterotrophic dinoflagellate, which has been associated with both fish deaths and a cause of human illness (Burkholder et al., 1992; Glasglow et al., 1995; Burkholder and Glasgow, 1997). This species possesses a complex life cycle that includes motile forms (e.g. zoospores, gametes, amoebae) and a cyst stage that may remain dormant in the sediment (Burkholder et al, 1995b). Pfiesteria piscicida is known to have toxin and non-toxin producing populations, where cyst transformation into the toxic motile zoospores may be initiated by the presence of certain …

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