Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium Artemia research at ARC

Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium 1.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 !

Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium 2. Artemia population assessment studies cfr. fluctuations in Great Salt Lake harvests abiotic conditions primary production Artemia population

Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium Karabogaz-Gol, Turkmenistan Russian Federation (Siberia) China (Tibet)

Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium Orius Podisus 3. Mass-rearing and biocontrol potential of predatory insects (Heteroptera, Coleoptera…) (Cooperation with Laboratory of Agrozoology, RUG) Harmonia

Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium nymph IV Orius 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)

Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium 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…)

Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium 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

Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium Rationale : Eukaryotes exist in close association with micro-organisms: symbiotic, pathogenic, neutral = EMCs (eukaryote microbial communities) Colonisation of EMCs by allochthonous organisms = 1 st step 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

Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium Host-Microbe Unit

Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium Microbe-Microbe Unit

Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium Mobile Genetic Element Unit

Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium 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

Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium opportunistic bacteria pathogenic bacteria probiotic bacteria Artemia as model organism partners: Laboratory of Aquaculture & Artemia Reference Center (RUG) Prof. Godelieve Criel (RUG) Laboratory for Microbial Ecology (RUG) Laboratory for Aquatic Ecology & Aquaculture (KULeuven) Objective: Study the mode of action of microbial organisms & verify hypotheses by use of axenically cultured organism

Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium research questions: 1. How do bacteria colonize the gut??

Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium ingestion? through the cuticula? through the gills? research questions: 1. How do bacteria colonize the gut? 2. How does a pathogen infect an aquatic organism?

Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium 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?

Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium First action: develop an axenic standard culture of Artemia autoclaved decapsulated  -irradiated culture vessels food cysts seawater

Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium Further actions: Laboratory of Aquaculture & Artemia Reference Center, Ghent University, Belgium 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.