Dynamique de recrutement, connectivité génétique, et stress

Dynamique de recrutement, connectivité génétique,
et stress environnemental entre populations de
poissons clowns des Iles Eparses
Suzanne Mills et Ricardo Beldade
CRIOBE USR 3278 CNRS EPHE UPVD
Giacomo Bernardi et Jimmy O’Donnell
Objectives
1. Relate the PLD, geographic range and FST
2. Connectivity between the isles Eparses
1. Maternal contribution to dispersal
(stress & temperature)
PLD context
Connectivity context
• Understand how species disperse
• Inform about size and location of MPAs
• Inform about resilience potential
-10
-5
Sites and species
-15
GLO
-20
JDN
BAS
-25
EUR
30
35
40
45
50
55
Pelagic larval duration
A. akallopisos
n
PLD
Widespread
A. allardi
(semi)Endemic
GLO
JDN
BAS
EUR
GLO
JDN
BAS
EUR
5
6
1
1
1
2
-
-
14
14
9
10
13.8 14.3
n.s.
PLD
Model species (II)
PLD = 7-14 days
PLD = 21-28 days
-10
-5
Model species (II)
-15
GLO
G L O
32
45
J D N
37
32
B A S
33
9
E U R
8
33
-20
JDN
BAS
-25
EUR
30
35
40
45
50
55
Genetic markers
Microsatellites = 9
Average number of alleles = 16
Assumptions (HW, LD)
Microsatellites = 13
Average number of alleles = 23
Assumptions (HW, LD)
Analysis
-12
3 distinct clusters
-14
Results Population structure
Population Structure between the:
-22
-20
-18
-16
•North (Glorieuses)
•Center (Juan de Nova)
•South (Europa and Bassas)
38
40
42
44
46
Estimated cluster membership
48
Results Population structure
1 single cluster
No Population Structure
-10
-5
Results past migration rate
GLO
-15
14
34
-20
19
Θ1 = 1603
11
JDN
56
Θ2 = 127
22
BAS
Θ3 = 1080
-25
EUR
30
35
40
45
50
55
-10
-5
Results past migration rate
Θ1 > 10000
-15
GLO
-20
JDN
Θ2 > 10000
BAS
Θ3 > 10000
-25
EUR
30
35
40
45
50
55
Conclusions
• Evidence of population structure for Amphiprion
akallopisos but NOT for Dascyllus trimaculatus
– MPA context
• Effective population sizes smaller in JDN;
• past migration rates smaller between Center and
North and South
l’avenir…
1. Determine SELF-RECRUITMENT
2. Epinephelus tukula
Population connectivity
Size at Maturity
Size at Sex change
Animals and plants exhibit a range of
dispersal strategies
Local environment
Does local
environment
affect larval
dispersal?
Physiology
Conditional dispersal strategy: flexible
dispersal, sensitive to habitat type,
local population type and other
predictors of local fitness.
Californian endemic sea slug
Alderia willowi
Anemonefish
Amphiprion chrysopterus
HIGH
SST
CORAL
*BLEACHING
EFFECTS ON
STRESS
RESPONSE
OF
BREEDERS
MATERNAL
EFFECTS ON
OFFSPRING
DISPERSAL
?
Amphiprion akallopisos
Stress response, cortisol
GLORIEUSES
x
INDIAN OCEAN
x
JUAN DE NOVA
x
*
x
x
x
*
EUROPA
*
x
x
Stress-induced cortisol
Sea surface temperatures (SST)
SST anomalies
1993 - 2011
Cortisol?
BioReCIE team
Pascale Chabanet (CoReUs, IRD)
Lionel Bigot (ECOMAR, Reunion)
How can the stress response be adjusted?
Mircoevolution
Phenotypic plasticity
Ecological or physiological
processes irreversibly modify the
phenotype and stress response
Early life
Adult
High chronic stress during
gestation
Induces a
persistent lifelong increased
responsiveness
of the HPA axis
Life-long reduced
response: efficacy
of -ve feedback,
ACTH receptor
desensitization,
hyperactivity
exhausts HPA axis.
= Sensitisation or
hypersecretion
= Desensitization
or downregulation
Are skunk anemonefish in the
South down-regulating their
cortisol levels?
Common frog,
Rana temporaria
Latitude
Time-constrained high-latitude
populations evolved lower CORT
response to chronic stress to maintain
higher growth under stressful
conditions
BUT, differences in growth and reproductive season are unlikely across the Iles Eparses
Were the populations in the North exposed to an environmental
stressor that was absent in Europa?
Glorieuses
Juan de Nova
Europa
SST anomalies have increased more in the
last 5 years in the North
Populations in the North exposed to higher SST anomalies
Recent high SST anomalies in the North
induced a life-long increased
responsiveness of the HPA axis resulting
in higher cortisol response to stress as
adults
What are the consequences of these elevated cortisol levels?
Field
manipulations
to induce
conspecific
stress:
Amphiprion chrysopterus
Moorea, French Polynesia
Cortisol levels
Fecundity
Dispersal
?
Future :
Egg size
Lipids
Fatty acids
Conclusions
• Climate warming not only affects biodiversity and abundance,
but also physiology: fish stress responses, which may reduce
their reproduction and ultimately survival.
• Populations in Europa, whose temperatures have increased at
a slower rate, are not similarly affected.
• Coral cover is high in Europa as are fish populations in general.
It is important to identify resistant regions or regions more
likely to persist as the climate changes. Europa (and other
southern islands) should be considered such high priority
islands.
Bilan:
Formation par la recherche :
2011-2012 DANIELLE BERGAZIN
2012-2013 HEATHER WILLIAMS
2011-2013 JAMES O’DONNELL
B.Sc.
M.SC.
Ph.D.
SFYI International School Oceanologie
UCSC, Santa Cruz, Californie
UCSC, Santa Cruz, Californie
Communications dans des conférences internationaux.
2012 Williams, H.E., O’Donnell, J.L, Beldade, R., Mills, S.C., & Bernardi, G.
Cross-amplification of 9 microsatellite loci for studies of population
connectivity among populations of the Skunk Anemonefish in the
Mozambique Channel. PhD Students meeting, KAUST, Saudi Arabia.
2012
O’Donnell, J.L, Beldade, R., Williams, H.E., Mills, S.C., & Bernardi, G.
Connectivity of damselfish populations in the Mozambique Channel inferred
from microsatellite analysis. 1st Joint Congress on Evolutionary Biology,
Ottawa, Canada.
2013
Mills, S.C., Beldade, R., Bernardi, G., Bigot, L., Chabanet, P., Holles, S.,
Mourier, J., O’Donnell, J., Planes, S., Radford, A. & Simpson, S.
Anthropogenic disturbances on the development and physiology of marine
species 14th Congress of the European Society of Evolutionary Biology
(ESEB), Lisbon, Portugal.
Bilan:
Articles publiés, soumis, en préparation.
S. C. MILLS, R. BELDADE, P. CHABANET, L. BIGOT, J. O’DONNELL AND G. BERNARDI
Climate change and fish stress response in the Iles Eparses
In revision à Coral Reefs
S. C. MILLS, R. BELDADE, J. O’DONNELL AND G. BERNARDI
Group size determines steroid levels in the skunk clownfish, Amphiprion
akallopisos, from the Iles Eparses
Soumis
O’DONNELL, J.L, BELDADE, R., WILLIAMS, H.E., MILLS, S.C., & BERNARDI, G.
Connectivity of damselfish populations in the Mozambique Channel inferred
from microsatellite and DNA sequence analysis.
In prep
MERCI :
Marion Dufresne
Inventive
Jean-Bernard Galves,
Jean-Francois Gros,
Jose Parodi
Organisateurs sur place
Cedric Marteaux
Zoë Glenard
Sophie Marinesque
Students
Hannah E. Williams (UCSC)
Danielle Bergazin (SFYI)
BioReCIE team
Pascale Chabanet, Lionel Bigot,
Pierre Barroil, Christophe Cadet,
Patrick Durville, Eric Hoarau,
Jean-Benoît Nicet, Emmanuel Tessier,
Thierry Mulochau
Maternal effects: transfer of maternal hormones to embryos allows a
mother to alter embryonic and larval development as a function of her
local environment
Dispersal or self
recruitment

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