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Artemia research at ARC. ARC ‘traditionals’: description of strain characteristics biometrics hatching & diapause characteristics lifespan & reproductive characteristics effect of abiotic conditions on growth, reproduction…. cross-breeding HUFA content ……..
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ARC ‘traditionals’: description of strain characteristics • biometrics • hatching & diapause characteristics • lifespan & reproductive characteristics • effect of abiotic conditions on growth, reproduction…. • cross-breeding • HUFA content • …….. • cooperation with other partners !
2. Artemia population assessment studies cfr. fluctuations in Great Salt Lake harvests • abiotic conditions • primary production • Artemia population
Russian Federation (Siberia) Karabogaz-Gol, Turkmenistan China (Tibet)
3. Mass-rearing and biocontrol potential of predatory insects (Heteroptera, Coleoptera…) (Cooperation with Laboratory of Agrozoology, RUG) Orius Harmonia Podisus
Cost-effective production of ‘killer bugs’ : production of large numbers at low price Use of Lepidopteran eggs, esp. of Mediterranean flour moth, Ephestia kuhniella • good development & reproduction of • predatory insects • high price • (high investment & production costs, • high demand, occasional market shortages) • possible human health problems (allergene) nymph IV Orius
Promising preliminary results : Artemia cysts as alternative to Ephestia eggs effect on growth, metamorphosis, survival, reproduction of predator… application techniques (decapsulated vs. non-decapsulated, hydration level…)
4. Proposal for a new VIB (Flemish Institute of Biotechnology) • Department : • Department of Microbial Ecology of Aquatic Invertebrates • Ghent University, Belgium • Laboratory of Microbial Ecology and Technology • Laboratory of Aquaculture & Artemia Reference Center • University of Connecticut, USA • Dalhousie University, Canada
Rationale : • Eukaryotes exist in close association with micro-organisms: symbiotic, pathogenic, neutral • = EMCs (eukaryote microbial communities) • Colonisation of EMCs by allochthonous organisms = • 1ststep in development of pathogenesis, commensalism, symbiosis. • Objective : • How do allochthonous micro-organisms establish themselves in the EMCs ? What factors • determine success or failure ? • new insights into host-pathogen and host-probiotic interactions • therapeutic and probiotic opportunities. • Model eukaryote:Artemia franciscana • Model allochthonous organisms: Vibrionaceae • pathogenic or beneficial to Artemia • culture collection available; extensive database available of chromosomal & mobile genetic elements important to Vibrio success in EMCs • common pathogens of almost all higher eukaryotes, • develop a comprehensive model of Vibrionaceae invasion and colonisation
5. FWO project: the functional role and characteristics of micro-organisms in the larviculture of aquatic organisms with Artemia as a test species • Rationale : • general trend towards more natural suppression of opportunistic/obligate • pathogens in aquaculture • consensus about critical role of microbial interactions • numerous questions about biological processes involved : • competition for adhesion sites in digestive tract • competition for nutrients • excretion of antibacterial products by bacteria/micro-algae • stimulation of immune system by algae/yeasts/bacteria • ……… • test organisms not cultured axenically interactions with micro-organisms
Artemia as model organism opportunistic bacteria pathogenic bacteria probiotic bacteria Objective: Study the mode of action of microbial organisms & verify hypotheses by use of axenically cultured organism partners: • Laboratory of Aquaculture & Artemia Reference Center (RUG) • Prof. Godelieve Criel (RUG) • Laboratory for Microbial Ecology (RUG) • Laboratory for Aquatic Ecology & Aquaculture (KULeuven)
research questions: 1. How do bacteria colonize the gut? 2. How does a pathogen infect an aquatic organism? through the gills? ingestion? through the cuticula?
research questions: 1. How do bacteria colonize the gut? 2. How does a pathogen infect an aquatic organism? 3. How does a ‘probiotic’ protect an aquatic organism?
First action: develop an axenic standard culture of Artemia autoclaved seawater culture vessels decapsulated cysts -irradiated food
Further actions: • Linked to the axenic cultures and using scanning-electron microscopy, an ‘atlas’ of a ‘normal’ gut of successive developmental stages would be compiled. • At a later stage, the colonization of the gut • by selected harmless and pathogenic • bacteria will be studied quantitatively and • qualitatively using diverse microbial • marker techniques (FiSH, DGE, GFP). • Besides, we will consider axenic • Dunaliella cultures as food source in order • to investigate the possible probiotic • role of algae. Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium