Article

The fate of Lyngbya majuscula toxins in three potential consumers.

Smithsonian Marine Station, Fort Pierce, FL 34949, USA.
Journal of Chemical Ecology (Impact Factor: 2.24). 08/2005; 31(7):1595-606. DOI: 10.1007/s10886-005-5800-5
Source: PubMed

ABSTRACT Blooms of Lyngbya majuscula have been reported with increasing frequency and severity in the last decade in Moreton Bay, Australia. A number of grazers have been observed feeding upon this toxic cyanobacterium. Differences in sequestration of toxic compounds from L. majuscula were investigated in two anaspideans, Stylocheilus striatus, Bursatella leachii, and the cephalaspidean Diniatys dentifer. Species fed a monospecific diet of L. majuscula had different toxin distribution in their tissues and excretions. A high concentration of lyngbyatoxin-a was observed in the body of S. striatus (3.94 mg/kg(-1)) compared to bodily secretions (ink 0.12 mg/kg(-1); fecal matter 0.56 mg/kg(-1); eggs 0.05 mg/kg(-1)). In contrast, B. leachii secreted greater concentrations of lyngbyatoxin-a (ink 5.41 mg/kg(-1); fecal matter 6.71 mg/kg(-1)) than that stored in the body (2.24 mg/kg(-1)). The major internal repository of lyngbyatoxin-a and debromoaplysiatoxin was the digestive gland for both S. striatus (6.31 +/- 0.31 mg/kg(-1)) and B. leachii (156.39 +/- 46.92 mg/kg(-1)). D. dentifer showed high variability in the distribution of sequestered compounds. Lyngbyatoxin-a was detected in the digestive gland (3.56 +/- 3.56 mg/kg(-1)) but not in the head and foot, while debromoaplysiatoxin was detected in the head and foot (133.73 +/- 129.82 mg/kg(-1)) but not in the digestive gland. The concentrations of sequestered secondary metabolites in these animals did not correspond to the concentrations found in L. majuscula used as food for these experiments, suggesting it may have been from previous dietary exposure. Trophic transfer of debromoaplysiatoxin from L. majuscula into S. striatus is well established; however, a lack of knowledge exists for other grazers. The high levels of secondary metabolites observed in both the anaspidean and the cephalapsidean species suggest that these toxins may bioaccumulate through marine food chains.

0 Followers
 · 
102 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Many people around the world depend on the marine environment, for its nutritional, recreational, and general economic value. For many years, a notable increase has been observed in the number of cases of severe intoxication, through the consumption of contaminated seafood and through external exposure. While dinoflagellates and diatoms are considered the main source of marine biotoxins, there is also growing evidence that certain groups of marine cyanobacteria are likely to produce various toxins with potential harmful effects on humans, especially in cases of massive proliferation. Some of the recent findings that support this hypothesis are summarized in this chapter.
    Outstanding Marine Molecules: Chemistry, Biology, Analysis, Edited by Stéphane La Barre, Jean-Michel Kornprobst, 03/2014; Wiley-VCH Verlag GmbH & Co. KGaA.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Lyngbya wollei is a benthic filamentous cyanobacterium that produces a toxin analogous to the neurotoxic saxitoxin known as lyngbyatoxin (LYNGTX). Microcystis aeruginosa form blooms in the pelagic area of eutrophic lakes and produce a series of potent hepatotoxins-microcystins (MCYST). The aim of this study in vitro study was to examine the difference between the crude extracts of either M. aeruginosa or L. wollei toward the immune system of Elliptio complanata mussels. Freshly isolated hemolymph was plated and exposed to the crude extract of each species at LYNGTX or MCYST equivalent concentrations of 5, 10 and 25 μg/L for 18 h. Immunocompetence was characterized by following changes in hemocyte numbers, metabolic activity (viability), and phagocytosis. Hemocyte counts were not affected, indicating no turnover of hemocytes. Hemocyte metabolic activity was higher in cells exposed to crude extracts of L. wollei. Exposure to L. wollei extracts led to decreased pro-inflammatory precursors such as reactive oxygen species (ROS) and cyclooxygenase (COX) activities. Phagocytosis increased at 25 μg/L for both types of crude extracts. However, hemocytes exposed to crude extracts of M. aeruginosa produced more ROS and COX compared to hemocytes exposed to crude extracts of L. wollei. In conclusion, the data suggest that the crude extract of M. aeruginosa was more toxic than crude extract of L. wollei to mussel hemocytes.
    Ecotoxicology 01/2014; 23(2). DOI:10.1007/s10646-013-1169-3 · 2.50 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The filamentous cyanobacterium Lyngbya wollei (Farlow ex Gomont) comb. nov. forms dark green to black mats on the bottom of rivers and lakes. Benthic mats often remain inconspicuous until they float to the surface because of trapped gas bubbles or until high winds and wave action dislodge and wash mats ashore. Mats induce dark, anoxic conditions conducive to nutrient mineralization, atmospheric N 2 fixation, and hetero-trophic metabolism. Lyngbya wollei has been found historically in southeastern USA, but genetically similar sub-groups have been proliferating more recently in the Laurentian Great Lakes and the St Lawrence River. This taxon is found under contrasting environmental conditions, including very clear, thermally and chemically stable, and heavily mineralized Florida Springs and turbid, high dissolved organic C, and seasonally variable conditions, influenced by agricultural tributaries in the St Lawrence River. Lyngbya wollei produces a number of unique sax-itoxins and volatile organic compounds that are responsible for a musty-earthy taste and odor in water, which affect aesthetics and recreational water uses. Mats of L. wollei are less palatable than other vegetation but provide shelter for invertebrates, which hide in dark mats of filaments. In the St Lawrence River, wetlands dominated by L. wollei tend to be characterized by a lower biomass of invertebrates and large fish, lower fish species richness, and slower-growing juvenile fish than macrophyte-dominated wetlands. Replacement of macrophytes by L. wollei mats induces a shift in trophic structure and coincides with a decrease in carrying capacity for fish, and signifi-cantly alters the dynamics of freshwater ecosystems. Increased occurrence of harmful algal blooms (HABs) worldwide, caused mainly by human activity, has impor-tant effects on aquatic ecosystems (O'Neil et al. 2012, Paerl and Otten 2013) via proliferation of potentially toxic species and episodic hypoxia (Heisler et al. 2008). In fresh-water environments, planktonic cyanobacteria and ben-thic chlorophytes are associated with eutrophication, as is the case for Microcystis blooms (Watson et al. 2008) and Cladophora proliferation (Hecky et al. 2004, Higgins et al. 2005) in the Laurentian Great Lakes. However, comparatively little is known about the more recent problems caused by benthic cyanobacterial blooms in freshwater. Like the morphologically similar filamen-tous chlorophyta, benthic filamentous cyanobacteria oc-cur in large mats suspended in the water column or on
    Freshwater science 06/2014; 33(2):606-618. · 1.42 Impact Factor

Full-text

Download
67 Downloads
Available from
Jun 6, 2014