Ostreopsis ovata

Ostreopsis ovata is the smallest species in the genus Ostreopsis. Its presence has been reported in numerous areas of the world such as the Pacific Ocean (Fukuyo 1981 Yasumoto et al. 1987), the Caribbean Sea (Tindall et al. 1990), the Brazilian coasts in the Atlantic Ocean (Graneli et al. 2002), and the Mediterranean Sea (Tognetto et al. 1995 Sansoni et al. 2003, Aligizaki et al. 2005 Penna etal. 2005). 

Graneli, E., Ferreira, C.E.L., Yasumoto, T, Rodrigues, E., Maria, H., and Neves, B. 2002. Sea urchins poisoning by the benthic dinoflagellate Ostreopsis ovata on the Brazilian Coast. Book of A bstracts, 10th International Conference on Harmful Algae, Florida, USA, p. 113. 

Simoni, E, Gaddi, A., Di Paolo, C., Lepri, L., Mancino, A., and Falaschi, A. 2004. Further investigation on blooms of Ostreopsis ovata, Coolia monotis, Prorocentrum lima on the macroalgae of artificial and natural reefs in the Northern Tyrrhenian Sea. Harmful Algae News 26 5-7. 

Tognetto, L., Bellato, S., Moro, L, and Andreoli, C. 1995. Occurrence of Ostreopsis ovata (Dinophyceae) in the Tyrrhenian... 

Another Potential Palytoxin Analogues from Ostreopsis ovata Origin and Distribution... 

Populations of Ostreopsis ovata (Fukuyo t98t), the smaller of members within of genus Ostreopsis, are usually found in protected, inshore regions from the tropical Pacific Ocean (Fukuyo 1981 Yasumoto et al. 1987 Quod 1994), the Caribbean Sea (Carlson and Tindall 1985), and the Tyrrhenian Sea (Tognetto et al. 1995). Unfortunately, only little iirformation was available until now about the toxic compounds produced by this species, but they are suspected to be related with paiytoxins. Likewise, its poisonous potential for health human is also unknown. 

Table 6.3. Toxicity test carried out on Ostreopsis ovata extracts collected in southern east Brazil coast...

A sample purified of an Ostreopsis ovata extract was lately assayed on actin cytoskeleton of isolated rabbit intestinal cells by Botana s group. The measure of a fluorescent dye bound specifically to actin filaments (Oregon green 514-phalloidin) showed that Ostreopsis ovata toxin also interfered the cytoskeleton as occurred in the two previous cases (Table 6.4). In addition, activity on membrane potential of neuroblastoma cells was studied through the fluorescent probe bis-oxonol. The purified extract displayed a depolarizing effect (the value of relative fluorescence obtained at 350 seconds for cells exposed to the sample was 1.49 0.12 versus control) also similar to palytoxin and ostreocin-D. Therefore, although these studies only shed very preliminary information abont the toxic compound produced by Ostreopsis ovata, they appear to point out some link between its cellular targets and those identified for palytoxin and ostreocin-D in these studies. 

Table 6.4. Biological activity of a sample purified of Ostreopsis ovata on actin cytoskeleton of rabbit enterocytes...

Ciminiello, R, Dell Aversano, C., Fattorusso, E., Forino, M., Magno, G.S., Tartaglione, L., Grillo, C. and Melchiorre, N., The Genoa 2005 outbreak. Determination of putative palytoxin in Mediterranean Ostreopsis ovata by a new liquid chromatography tandem mass spectrometry method. Analytical Chemistry, 78, 6153, 2006. 

Ostreopsis ovata is usually found in protected, inshore areas in tropical and snbtropical regions of the tropical Pacific Ocean, the Caribbean Sea, and the Tyrrhenian Sea, bnt in recent years has been found frequently in the Mediterranean Sea. During summer 2005, symptoms of rhinor-rhea, cough, fever, bronchoconstriction with mild dyspnea, and wheezing were observed in people exposed to marine aerosols in Genoa, Italy. Seawater samples were found to have high densities of... 

Yasumoto, T. et al.. Toxins produced by benthic dinoflageUates, Biol. Bull. 172, 128, 1987. Brescianini, C. et al., Ostreopsis ovata algal blooms affecting human health in Genova, Italy, 2005 and 2006, Eurosurveillance weekly releases 2006 11, 2006. 

Besada EG, Loeblich LA, Loeblich AR EQ (1982) Observations on tropical benthic dinoflagellates from ciguatera endemic areas Coolia monotis, Gambierdiscus toxicus and Ostreopsis ovata. Bull Mar Sci 32(3) 723-735. 

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