Study of potential prophylactic effect by marennine by utilisation of Haslea ostrearia Simonsen as oyster’s feed

Presented by:Fiddy S. PRASETIYA

Supervised by:Dr. Jean-Luc MOUGETDr. Bruno COGNIEDr. Michèle MORANCAISDr. Yann HARDIVILLIERDr. Romain GASTINEAU

Fiddy SEMBA PRASETIYA, 1st year PhD student Université du MaineStudy of potential prophylactic effect by marennine by utilisation of Haslea ostrearia Simonsen as oyster’s feed

Part I:Selective feeding of Crassostrea gigas Thunberg on

different sizes of Haslea ostrearia Simonsen

Part 1

Fiddy SEMBA PRASETIYA, 1st year PhD student Université du MaineStudy of potential prophylactic effect by marennine by utilisation of Haslea ostrearia Simonsen as oyster’s feed

• Intensive cultured of C. gigas in seawater ponds

• Presence of diatoms (90%) in oyster ponds

• H. ostrearia and greening phenomenon in oysters

• Presence of marennine increases the economic value of cultured oysters

• Further research on H. ostrearia and marennine

Introduction Objective Methodology Results Conclusion

Source: www.fao.org

Study background

Fiddy SEMBA PRASETIYA, 1st year PhD student Université du MaineStudy of potential prophylactic effect by marennine by utilisation of Haslea ostrearia Simonsen as oyster’s feed

• H. ostrearia in oyster ponds differs in size on the apical length of the frustule (60 – 120 µm)

• Different sizes of H. ostrearia co-exist in the same pond while C. gigas feeding

• Selection of particles by C. gigas as a mechanism of feeding

Introduction Objective Methodology Results Conclusion

Fiddy SEMBA PRASETIYA, 1st year PhD student Université du MaineStudy of potential prophylactic effect by marennine by utilisation of Haslea ostrearia Simonsen as oyster’s feed

• Mechanism of feeding by bivalves, encompass:– Retention particle– Preingestive selection– Postingestive selection

• Preingestive selection influenced by:– Particle shape– Particle size– Particle chemical/biochemical

characteristics– Combination between

parameters

Introduction Objective Methodology Results Conclusion

Fiddy SEMBA PRASETIYA, 1st year PhD student Université du MaineStudy of potential prophylactic effect by marennine by utilisation of Haslea ostrearia Simonsen as oyster’s feed

• Inconsistensy of preingestive selection on bivalves according to their size: – Larger algal cells (>10µm) rejected on Anodonta

calipygos (Miura & Yamashiro, 1990)– No effect of particle size (2-64µm) preference on

Mytilus edulis, C. gigas & Placopecten magellanicus (Macdonald & Ward, 1994)

– Smaller algal cells (<70µm) preferentially accepted in C. gigas (Cognie et al., 2003)

Introduction Objective Methodology Results Conclusion

Fiddy SEMBA PRASETIYA, 1st year PhD student Université du MaineStudy of potential prophylactic effect by marennine by utilisation of Haslea ostrearia Simonsen as oyster’s feed

• To investigate the influence of particle size on C. gigas by using mixture of H. ostrearia composed of 2 distinct sizes, on sorting process in pallial organs involved (particularly in gills)

• Is there any preference on cell sizes in preingestive selection ?

Hypothesis tested•Ho = Cell proportion NOT significantly different at sampling sites•H1 = Cell proportion significantly different at sampling sites•H1a = Cell proportion significantly different in water and at dorsal and/or ventral tracts

Introduction Objective Methodology Results Conclusion

Fiddy SEMBA PRASETIYA, 1st year PhD student Université du MaineStudy of potential prophylactic effect by marennine by utilisation of Haslea ostrearia Simonsen as oyster’s feed

• 2 sizes of H. ostrearia populations: (small and large), 60 L, (3.106cells.l-1)

• 10 adult oysters were acclimated, flow rate 10 L.h-1

PF

Inflow

Outflow

• Sampling in each 15’, during 1h, at outflow

• Sampling of PF at the end of observation

• Fixed with Lugol & counted with biometric microscope

Introduction Objective Methodology Results Conclusion

Fiddy SEMBA PRASETIYA, 1st year PhD student Université du MaineStudy of potential prophylactic effect by marennine by utilisation of Haslea ostrearia Simonsen as oyster’s feed

• Video endoscopy directed-sampling

• Endoscopy sampling at gill dorsal, SD (acceptance) and gill ventral, GV (rejected)

SD GV

Fixed with Lugol & counted with biometric microscope

Introduction Objective Methodology Results Conclusion

Fiddy SEMBA PRASETIYA, 1st year PhD student Université du MaineStudy of potential prophylactic effect by marennine by utilisation of Haslea ostrearia Simonsen as oyster’s feed

Data analysis:- Homogenity &

Normality test- T-test (XLSTAT)

Cell proportion in inflow, outflow and pseudofaeces

Note: *, P-value < 0,05

Introduction Objective Methodology Results Conclusion

*

• Same proportion in inflow & outflow• Rejection of ‘large’ cells in pseudofaeces (26% higher than inflow)

Cel

l pro

port

ion

(%)

Site selection

Fiddy SEMBA PRASETIYA, 1st year PhD student Université du MaineStudy of potential prophylactic effect by marennine by utilisation of Haslea ostrearia Simonsen as oyster’s feed

*

Cell proportion in Dorsal and Ventral tractsC

ell p

ropo

rtio

n (%

)

Introduction Objective Methodology Results Conclusion

Site selection

• In dorsal tract, ‘Small’ cells were 19% higher than in ventral tract & pseudofaeces

Fiddy SEMBA PRASETIYA, 1st year PhD student Université du MaineStudy of potential prophylactic effect by marennine by utilisation of Haslea ostrearia Simonsen as oyster’s feed

*Note: *, P-value < 0,05SD, dorsal tractsGV, ventral tracts

• Selection occured in pallial organs of C. gigas • Seston size significantly influenced the sorting process in C.

gigas• Rejection of ‘large‘ cells of H. ostrearia in form of

pseudofaeces • Present study has confirmed the previous experiment by

Cognie et al. (2003)

Introduction Objective Methodology Results Conclusion

Fiddy SEMBA PRASETIYA, 1st year PhD student Université du MaineStudy of potential prophylactic effect by marennine by utilisation of Haslea ostrearia Simonsen as oyster’s feed

Acknowledgement:•Dr. Priscila-D. Cognie•Dr. Pierre Gaudin•Amandine Figiel•CAMPUS FRANCE

THANK YOU…MERCI…

TERIMA KASIH

Introduction Objective Methodology Results Conclusion

Fiddy SEMBA PRASETIYA, 1st year PhD student Université du MaineStudy of potential prophylactic effect by marennine by utilisation of Haslea ostrearia Simonsen as oyster’s feed