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Current knowledge and perspectives of study on benthic toxic dinoflagellates of the genus Gambierdiscus in the Canary Islands F. Rodríguez S. Fraga P.

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Presentation on theme: "Current knowledge and perspectives of study on benthic toxic dinoflagellates of the genus Gambierdiscus in the Canary Islands F. Rodríguez S. Fraga P."— Presentation transcript:

1 Current knowledge and perspectives of study on benthic toxic dinoflagellates of the genus Gambierdiscus in the Canary Islands F. Rodríguez S. Fraga P. Riobó JM. Franco ICES Annual Science Conference September A Coruña

2 Gambierdiscus 40ºN 40ºS ICES Annual Science Conference (Source: Litaker et al., 2010, GEOHAB 2012; Fraga et al., in rev.)

3 Tenerife Gran Canaria Fuerteventur a Lanzarote Seriola rivoliana ©J. Padillo Rivademar Intoxication cases in Canaries ( ). (Source: Eurosurveillance, Diario de Avisos, La Provincia) Most cases linked with consumption of amberjack (Seriola spp.) A subtropical archipelago influenced by the NW African upwelling system. Total population 2.1 million people. Tourism-based economy. First official ciguatera cases in 2008: emerging problem. ~100 people affected between ICES Annual Science Conference Canary Islands Last intoxication case: 10 people in Lanzarote (December 2013) Epinephelus marginatus

4 Gambierdiscus in Canary Is. Five opportunistic surveys (2004, 2005, 2008, 2010 and 2013). Gambierdiscus presence Not found Tenerife (2004, 2013) La Palma (2005) La Gomera (2010) Gran Canaria (2013) Lanzarote (2008, 2013) Collected from small mixed seaweeds in tidal ponds and rocks, (exposed areas to the NE trade winds and southern locations). Manual isolation and laboratory cultures. ICES Annual Science Conference X X X

5 G. excentricus Tenerife (2004, 2013) La Palma (2005) La Gomera (2010) Gran Canaria (2013) Three Gambierdiscus species were isolated in the archipelago: G. excentricus (Fraga et al. 2011), G. australes and G. silvae sp. nov (Fraga et al. in rev.). G. australes G. silvae Cultures were characterized by means of light microscopy, SEM, molecular phylogeny, pigments and toxins. ICES Annual Science Conference Gambierdiscus in Canary Is.

6 G. silvaeG. australesG. excentricus

7 Molecular taxonomy Phylogeny based on LSUrDNA (D1- D3) (Fraga et al in rev.) G. silvae G. excentricus G. australes

8 Gambierdiscus excentricus chl c2, c1, Peridinin*, Diadinoxanthin, Dinoxanthin, chl a,  -carotene. ICES Annual Science Conference (Fraga et al 2011) Pigment composition *

9 ICES Annual Science Conference It has a Po plate ventrally displaced in relation to other species of the genus Gambierdiscus. Anteroposteriorly compressed. 1. Gambierdiscus excentricus (Fraga et al, 2011) Morphological characterization

10 (Fraga et al, 2011)

11 ICES Annual Science Conference 2. Gambierdiscus silvae sp. nov Formerly known as Gambierdiscus ribotype I (Litaker et al 2009) sequenced from the field (Belize). Sister species of G. polynesiensis. Plates 1’, 4’ and 1’’ do not form a distinct fold like in G.polynesiensis. A: U-shaped nucleus B: chloroplasts in G. silvae (Fraga et al, in rev.)

12 ICES Annual Science Conference 2. Gambierdiscus silvae sp. nov (Fraga et al in rev.)

13 ICES Annual Science Conference 2. Gambierdiscus silvae sp. nov (Fraga et al in rev.)

14 3. Gambierdiscus australes Previously found in the Pacific Ocean. Strain VGO1161 (Tenerife; Fraga et al., in rev.)

15 G. excentricusG. australesG. silvae

16 ICES Annual Science Conference Toxins 1. Gambierdiscus excentricus Ciguatoxin (CTX) and Maitotoxin (MTX) producer according to Neuro2a-CB. (Caillaud et al, 2010; Fraga et al, 2011)

17 ICES Annual Science Conference 2. Gambierdiscus silvae sp. nov Toxicity screening by MBA analyses & Mass spectrometry (Orbitrap and a HESI-II probe ). MBA analyses of G. silvae toxins extracts showed CTXs bioactivity: death at <4 hours (MeOH, MTXs), <7 hours (dicloromethane, CTXs). HR full MS experiments indicated presence of 2,3 dihydroxi CTX3C and CTX1B or P- CTX1. Toxins (Riobó and Franco, unpublished) C57H84O18 Isotopic pattern

18 Conclusions and perspectives of study ICES Annual Science Conference CFP reported in Canary Islands since 2008 affected a limited number of people (~100). Gambierdiscus has been always found in low concentrations. A new project is starting to obtain more complete information about the temporal and geographical distribution of Gambierdiscus as a potential local source of ciguatera.

19 Thank you for your attention !!


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