The Fate of Lyngbya majuscula Toxins in Three Potential Consumers

Smithsonian Marine Station, Fort Pierce, FL 34949, USA.
Journal of Chemical Ecology (Impact Factor: 2.75). 08/2005; 31(7):1595-606. DOI: 10.1007/s10886-005-5800-5
Source: PubMed


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.

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    • "Saxitoxins are known as sodium channel blockers in the brain; however, the toxicity of the freshwater L. wollei is less studied than its marine congener L. majuscule. The marine L. majuscule is known to produce saxitoxins, and over 70 bioactive compounds such as microcolin B, ypaoamide, malyngolide, barbamide (Nagle and Paul 1998; Capper et al. 2005) and, in particular, immunosuppressive peptides like microlin A and B (Yasumoto 1998). The toxicity of these toxins towards the immune status in freshwater mussels is poorly understood at the present time. "
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    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 · 2.71 Impact Factor
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    • "The potent tumour promoter, lyngbyatoxin-A (LTA), has also been implicated as a co-factor in FP aetiology in the turtles in the Pacific (Arthur et al., 2008). LTA is produced by Lyngbya majuscula (Cardellina et al., 1979) and has been detected in high concentrations in a number of locations worldwide (Capper et al., 2005; Arthur et al., 2008). This highly adaptive benthic cyanobacteria has been increasingly observed in Florida freshwater, estuarine and marine ecosystems in recent years (Landsberg et al., 2003; Burns, 2008; Pinowska et al., 2009), proliferating in the reef-associated communities of south Florida (Paul et al., 2005); with ephemeral blooms in the Indian River Lagoon (Capper and Paul, 2008) and Sanibel, west Florida (Paerl et al., 2008). "
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    ABSTRACT: Florida is a hotspot for cyano- and microalgal harmful algal blooms (HABs) with annual red-tide events off-shore and blooms of Lyngbya spp. commonly observed in both marine and freshwater environments. This region also provides extensive foraging habitat for large populations of herbivorous green turtles (Chelonia mydas) and manatees (Trichechus manatus latirostris). The exposure of aquatic organisms to HAB toxins is not well known and whilst acute exposures are better understood, the vulnerability of aquatic animals to chronic exposure from multiple HAB toxins over prolonged periods has rarely been addressed. This study aimed to identify the presence of toxic compounds produced by HAB species commonly found in Florida (brevetoxins, okadaic acid, saxitoxins and Lyngbya toxins) in tissues and gut samples from manatee and green sea turtles that stranded in Florida, USA. Muscle, liver and alimentary tract samples were opportunistically collected from 14 manatees and 13 green turtles that stranded on the Florida shoreline between December 2003 and February 2006. Samples from each animal were assessed for the presence of brevetoxin, okadaic acid, lyngbyatoxin-A and saxitoxin. Nine (64%) manatees and 11 (85%) turtles were found to have been exposed to one or more of the HAB toxins. Okadaic acid and saxitoxin were only found in alimentary tract samples, whereas brevetoxin was more widely distributed. No lyngbyatoxin-A was observed in any tissue samples. The majority of turtles (13) stranded on the Atlantic coast between St. Johns and Monroe counties, with one on the Gulf coast at Bay County, whereas nine manatees were stranded on the Gulf coast between Levy and Lee counties, with the remaining five between Volusia and Brevard counties on the Atlantic coast. This HAB toxin screen has identified that a large proportion of a random sample of turtles and manatees that stranded in Florida in 2003–2006 were exposed to HAB toxins. Most of the concentrations measured were low, and the toxins were directly linked to the death of only three of these animals. However, the presence of these compounds, and in some cases the presence of multiple HAB toxins in individual animals, indicates that turtles and manatees in Florida are exposed to deleterious compounds at sub-lethal levels in their environment, which could ultimately compromise their health.
    Harmful Algae 08/2013; 28:1–9. DOI:10.1016/j.hal.2013.04.009 · 3.87 Impact Factor
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    • "In keeping with the qualitative nature of LTA, specialist grazers, most notably including the sea hare, Stylocheilus striatus, preferentially graze and grow well on diets of LTA-containing L. majuscula, and are actually stimulated to feed by crude LTA extracts, even without prior exposure to the toxin [36]. Furthermore, S. striatus is actually found to sequester LTA, particularly in digestive gland, as well as ink, fecal matter and body tissue [42–43]. Though the possible role of this sequestered toxin in defense of the sea hare is unclear [44–45], it is noteworthy that there have, indeed, been several similar cases of putative cyanobacterial (and other algal) origins for toxins isolated from sea hares [46–47]. "
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    ABSTRACT: Cyanobacteria ("blue-green algae") from marine and freshwater habitats are known to produce a diverse array of toxic or otherwise bioactive metabolites. However, the functional role of the vast majority of these compounds, particularly in terms of the physiology and ecology of the cyanobacteria that produce them, remains largely unknown. A limited number of studies have suggested that some of the compounds may have ecological roles as allelochemicals, specifically including compounds that may inhibit competing sympatric macrophytes, algae and microbes. These allelochemicals may also play a role in defense against potential predators and grazers, particularly aquatic invertebrates and their larvae. This review will discuss the existing evidence for the allelochemical roles of cyanobacterial toxins, as well as the potential for development and application of these compounds as algaecides, herbicides and insecticides, and specifically present relevant results from investigations into toxins of cyanobacteria from the Florida Everglades and associated waterways.
    Marine Drugs 02/2008; 6(2):117-46. DOI:10.3390/md20080007 · 2.85 Impact Factor
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