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: 2.46). 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 Bookmarks
 · 
65 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: The analysis of a variety of environmental samples and the installation of passive solid phase adsorption devices (SPATT) in two warm-temperate estuaries (Rangaunu and Parengarenga Harbours), during consecutive summers (2009 and 2010), revealed the pervasive influence of bioactive polyether compounds secreted by benthic dinoflagellates within the mangrove and sea-grass habitats. Pinnatoxin (PnTx) analogues PnTx-E and PnTx-F and okadaic acid (OA) and its esters were the most abundant, though traces of other polyether compounds (dinophysistoxins, pectenotoxin, spirolides), were also detected. In sediments, algal mats and micro-algal films, the parent compound PnTx-F was the predominate analogue. In bivalves and gastropods PnTx-E and PnTx-F were either present in equivalent amounts or there was a predominance of the former, indicative of in vivo metabolism. Esterified OA was the predominant form of this toxin in the deposit feeding sea hare Bursatella leachii, however OA-toxins were only about 14% as abundant as the combined PnTx analogues in this animal. Conversely levels of PnTxs accumulated within the SPATT bags were only 50% of total-OA, about 10% of which was in the form of OA-esters. Neither OA nor OA-esters were observed in the oyster Crassotrea gigas. The levels of total-PnTxs in C. gigas were about 8% of that observed in B. leachii (200 and 2580 μg/kg respectively). Although there was abundant OA in this environment, cultured oysters did not incorporate this toxin presumably because they were not exposed to Prorocentrum lima cells in the water column or were unable to digest these cells. The low levels of pinnatoxins sequestered by oysters in these estuaries, despite persistent and very abundant populations of the causative dinoflagellate, is probably also due to the general inaccessibility of these cells to the shellfish and therefore there appears to be a low risk to human consumers
    Harmful Algae 01/2011; 10(6):559-566. · 2.90 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Increasing concerns about the ecological impacts of ongoing and possibly worsening blooms of the toxic, carcinogenic cyanobacteria Lyngbya majuscula in Moreton Bay, Australia, led us to assess differences in meiofaunal prey assemblages between bloom and nonbloom substrates and the potential dietary impacts of dense L. majuscula blooms on the omnivorous benthivore, the Eastern Long-finned Goby, Favonigobius lentiginosus and the obligate meiobenthivorous juveniles of Trumpeter Whiting, Sillago maculata. Marked differences in invertebrate communities were found between sandy and L. majuscula bloom foraging substrates, with copepods significantly more abundant (18.49% vs. 70.44% numerical abundance) and nematodes significantly less abundant (55.91% vs. 1.21% numerical abundance) within bloom material. Gut analyses showed that bentho-planktivorous fishes exposed to L. majuscula in captivity had consumed a significantly greater quantity of prey by both total number (P\0.0019) and volume (P\0.0006) than fish exposed to sand treatments. Thus, it is likely for such fishes that L. majuscula blooms increase rates of prey encounter and consumption, with consequent changes in trophic relationships through shifts in predator–prey interactions between small benthivorous fishes and their meiofaunal prey. Yes Yes
    Marine Biology 01/2011; · 2.47 Impact Factor
  • 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; · 2.77 Impact Factor

Full-text

View
36 Downloads
Available from
Jun 6, 2014