Showing papers by "Patricia A. Tester published in 2005"
TL;DR: Based on the plate tabulations for P. shumwayae, P. piscicida, and the closely related “cryptoperidiniopsoid” and “lucy” groups, the family Pfiesteriaceae is amended to include species with the following tabulation; the tabulation is expanded to increase the number of sulcal plates and to include a new plate, the peduncle cover (PC) plate.
Abstract: Pfiesteria shumwayae Glasgow et Burkholder is assigned to a new genus Pseudopfiesteria gen. nov. Plate tabulation differences between Pfiesteria and Pseudopfiesteria gen. nov. as well as a maximum likelihood phylogenetic analysis based on rDNA sequence data warrant creation of this new genus. The Kofoidian thecal plate formula for the new genus is Po, cp, X, 4′, 1a, 6′′, 6c, PC, 5+s, 5′′′, 0p, 2′′′′. In addition to having six precingular plates, P. shumwayae comb. nov. also has a distinctive diamond or rectangular-shaped anterior intercalary plate. Both Pfiesteria and Pseudopfiesteria gen. nov. are reassigned to the order Peridiniales based on an apical pore complex (APC) with a canal (X) plate that contacts a symmetrical 1′, four to five sulcal plates, and the conservative hypothecal tabulation of 5′′′, 0p, and 2′′′′. These morphological characters and the life histories of Pfiesteria and Pseudopfiesteria are consistent with placement of both genera in the Peridiniales. Based on the plate tabulations for P. shumwayae, P. piscicida, and the closely related “cryptoperidiniopsoid” and “lucy” groups, the family Pfiesteriaceae is amended to include species with the following tabulation: 4-5′, 0-2a, 5-6′′, 6c, PC, 5+s, 5′′′, 0p, and 2′′′′ as well as an APC containing a pore plate (Po), a closing plate (cp), and an X plate; the tabulation is expanded to increase the number of sulcal plates and to include a new plate, the peduncle cover (PC) plate. Members of the family have typical dinoflagellate life cycles characterized by a biflagellated free-living motile stage, a varying number of cyst stages, and the absence of multiple amoeboid stages.
55 citations
TL;DR: The congruence between Margalef’s prediction and the distribution of dinoflagellates in these naturally eutrophic systems suggests that increased nutrient inputs in oligotrohic portions of the Caribbean will favor a shift in species dominance toward dinof lagellate species.
Abstract: Dinoflagellates are frequently abundant in the coral-reef mangrove lagoons off the coast of Belize. Margalef predicted that marine environments with low turbulence and high nutrient inputs would favor dinoflagellates. A long-term study of coral-reef mangrove embayment cays of Belize, including this study, has shown that these systems contain abundant dinoflagellate species. Consistent with Margalef’s prediction, these habitats are protected from wind mixing, show a high degree of stratification, and have restricted water exchange with surrounding oligotrophic waters of the open barrier-reef system. This limited water exchange favors retention of dinoflagellate cells and the trapping of nutrient rich organic material that is rapidly recycled providing a relatively high-nutrient environment. Species-specific blooms are a common feature of these systems. In the study, the ecology and diversity of dinoflagellate species from two nutrient-enriched habitats, Douglas Cay and The Lair at Twin Cay, were examined in detail. A comparison of the species composition from both sites showed that Douglas Cay contained coastal planktonic and offshore oceanic dinoflagellates while The Lair at Twin Cay contained mainly benthic dinoflagellates. A total of 19 bloom-forming species were observed in these systems during three two-week studies. The morphology of eight of these bloom-forming species is illustrated in Scanning Electron Microscopy (SEM) photographs. These include Bysmatrum caponii, Dinophysis caudata, Gonyaulax grindleyi, Peridinium quinquecorne, Gonyaulax polygramma, Gonyaulax spinifera, Lingulodinium polyedrum, and Pyrodinium bahamense var. bahamense. Approximately half of the bloom-forming dinoflagellates are known toxin producers. The congruence between Margalef’s prediction and the distribution of dinoflagellates in these naturally eutrophic systems suggests that increased nutrient inputs in oligotrohic portions of the Caribbean will favor a shift in species dominance toward dinoflagellate species. The effect will be most pronounced in bays or other regions where turbulence is likely to be reduced. This species shift may have consequences for food web dynamics and the prevalence of dinoflagellate toxins in the food chain. _______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________ 1 Department of Botany, National Museum of Natural History, Smithsonian Institution, Washington D.C., 20560. 2 NOS/NOAA, Center for Coastal Fisheries Habitat Research, 101 Pivers Island Road, Beaufort, North Carolina, 28516. Manuscript received 29 July 2005; revised 22 August 2005.
36 citations
TL;DR: Given DMSP's putative antioxidant function, the increase in DMSPP:chl a ratios may represent a physiological response to help protect algal cells from increased oxidative stress during the day linked to solar UV-radiation and photosynthesis.
Abstract: Dimethylsulfoniopropionate (DMSP) and algal pigments were measured in waters from a variety of sites in the Belize coastal lagoon and adjacent barrier reef system. Particulate concentra- tions of DMSP (DMSPP) and chl a varied by 2 orders of magnitude (1.1 to 130 nmol l -1 for DMSP and 0.040 to 2.9 µg l -1 for chl a). DMSPP was correlated with chl a (r 2 = 0.83) based on regression analysis of log-transformed data. It was even more closely correlated with peridinin (r 2 = 0.92) and the photo- protective pigment diadinoxanthin (r 2 = 0.90), indicator pigments for dinoflagellates, a high-DMSP algal group. By contrast, DMSPP was poorly correlated with zeaxanthin (r 2 = 0.13), a marker for cyanobacteria which are thought to contain little or no DMSP. The highest DMSPP and chl a concen- trations and highest mean DMSPP:chl a molar ratio (39 ± 12) were observed in a eutrophic mangrove embayment, whose phytoplankton community was dominated by dinoflagellates. Much lower chl a and DMSPP values and a somewhat lower average DMSPP:chl a molar ratio (29 ± 14) were observed at sites in the vicinity of the outer barrier reef/island system, where an estimated 64% of the chl a on average occurred in cyanobacteria. In a diel study at one of these sites, the DMSPP/chl a ratio increased during the day and decreased at night, a pattern that did not appear to be caused by vari- ations in the algal community. The diel pattern instead may reflect a daytime increase in cellular DMSP concentration. Given DMSP's putative antioxidant function, the increase in DMSPP:chl a ratios may represent a physiological response to help protect algal cells from increased oxidative stress during the day linked to solar UV-radiation and photosynthesis.
16 citations
4 citations
18 Sep 2005
TL;DR: In this paper, the results from SeaWiFS field calibration using data collected from coastal North Carolina were compared with two contrasting water types, Case I water from the Gulf Stream off of North Carolina and Case II water from Pamlico Sound.
Abstract: The Sea-viewing Wide Field-of-view Sensor (SeaWiFS) satellite has been used to measure reflectances in six visible light bands for over seven years. Through various algorithms researchers are able to derive estimated chlorophyll concentrations. SeaWiFS needs to be validated by in situ data in order to assess the accuracy of the derived chlorophyll concentration. In this paper we will compare results from SeaWiFS field calibration using data collected from coastal North Carolina. We will compare two contrasting water types, Case I water from the Gulf Stream off of North Carolina and Case II water from the Pamlico Sound.
1 citations