current knowledge and perspectives of study on benthic toxic dinoflagellates of the genus...
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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. FragaP. RiobóJM. Franco
ICES Annual Science Conference
15-19 September 2014. A Coruña
Gambierdiscus
40ºN
40ºS
ICES Annual Science Conference
(Source: Litaker et al., 2010, GEOHAB 2012; Fraga et al., in rev.)
Tenerife
Gran Canaria
Fuerteventura
Lanzarote
Seriola rivoliana ©J. Padillo Rivademar
Intoxication cases in Canaries (2008-2013).
(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 2008-2013.
66
6
295
ICES Annual Science Conference
Canary IslandsLast intoxication case: 10 people in Lanzarote
(December 2013)
Epinephelus marginatus
Gambierdiscus in Canary Is.• Five opportunistic surveys (2004, 2005, 2008, 2010 and
2013).
Gambierdiscus presenceNot 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.
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XXX
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. australesG. silvae
• Cultures were characterized by means of light microscopy,
SEM, molecular phylogeny, pigments and
toxins.
ICES Annual Science Conference Gambierdiscus in Canary Is.
Gambierdiscus in Canary Is.
G. silvae
G. australes
G. excentricus
Molecular taxonomy
• Phylogeny
based on LSUrDNA
(D1-D3)(Fraga et al in rev.)
G. silvaeG. excentricus
G. australes
Gambierdiscus excentricus
chl c2, c1, Peridinin*,
Diadinoxanthin, Dinoxanthin,
chl a, b-carotene.
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(Fraga et al 2011)
Pigment composition
*
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• 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
(Fraga et al, 2011)
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 nucleusB: chloroplasts in G. silvae
(Fraga et al, in rev.)
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2. Gambierdiscus silvae sp. nov
(Fraga et al in rev.)
ICES Annual Science Conference
2. Gambierdiscus silvae sp. nov
(Fraga et al in rev.)
3. Gambierdiscus australes
• Previously found in the Pacific Ocean.
Strain VGO1161 (Tenerife; Fraga et al., in rev.)
G. excentricus
G. australesG. silvae
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Toxins
1. Gambierdiscus excentricus
• Ciguatoxin (CTX) and Maitotoxin (MTX) producer according to Neuro2a-
CB.
(Caillaud et al, 2010; Fraga et al, 2011)
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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
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.
Thank you for your attention !!