meagre, Argyrosomus regius

Transcription

1 Systemic granulomas in cultured meagre, Argyrosomus regius Pantelis Katharios, Konstantina Kokkari, Maria Papadaki, Nikos Papandroulakis Institute of Aquaculture Hellenic Centre for Marine Research

2 Meagre, Argyrosomus regius

3 Diseases reported

4 A new systemic granulomatous disease Visceral granulomas Calcification of the liver White cysts in heart Unilateral blindness Eroded fins Cachectic fish

5 Epidemiology

6 Liver calcification

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11 Fish examined Age group N Source Water 0+ (up to 1 month) >80 only histology Hatchery Borehole water 0+ (2 months) >1000 only X ray Hatchery Borehole water 0+ (5 months) 20 X ray + Anatomy Hatchery Borehole water Sea cages Natural sea water Sea cages Natural sea water 3+ 6 Sea cages Natural sea water 6+ 1 Hatchery Borehole water Analyses Performed: Histology, Microbiology, Parasitology, Haematology, Radiography, SEM, TEM, PCR

12 heart

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14 heart

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16 Liver calcification

17 Alizarin stain Alizarin stain counterstained with ihfast green

18 TEM, collagen microfibrils

19 TEM: Crystal structure 100 nm Electron diffraction: Crystal structure

20 Histological findings Concentric lamellated calcified granulomas in soft tissues Dystrophic Calcification of the liver Focal Necrosis and nuclear debris Massive proliferation of connective tissue with extended presence of collagen microfibrils il Nanocrystals No lesions in fish of 0+ (larvae 36 dph)

21 Differential diagnosis Systemic mycosis Parasites (microsporidia) Mycobacteriosis Neoplasia Metabolic disorder No hyphae, h negative PCR with ihuniversal primers No microscopic findings, negative with PCR with universal primers Negative with Ziehl Neelsen stain and with PCR with Uni No histological features (mitotic figures etc)

22 Granulomas vs Dystrophic calcification Granulomas Not common Characteristic morphology Onset is likely a cellular damage Dystrophic calcification Calcification of necrotic dead tissue Amorphous Associated with: Tissue damage

23 Metabolic disorder? Metastatic calcification Dystrophic calcification Abnormal deposition of calcium salts in soft tissue Associated with elevated calcium and phosphorus levels in serum Affects many tissues Abnormal deposition of calcium salts in soft tissue NOT associated with elevated calcium and phosphorus levels in serum More localized

24 Serum Ca/P 16 b a, b 14 a mild severe normal Meagre mild Meagre severe Sea bass normal a b c Meagre mild Meagre severe Sea bass normal Meagre Sea bass mild severe normal Meagre Sea bass Fish N Meagre with mild problem 15 Meagre with severe problem 5 Normalsea bass 3

25 Juvenile fish

26 Juvenile fish X ray lesions Batch Water supply Feed type Prevalence Prevalence (%) Mes4 Borehole Artemia 71/183 38,8 Mes5 Borehole Artemia 129/267 48,3 Mes6 Borehole Artemia 62/174 35,6 MesBig Borehole Artemia 111/163 68,1 HBA Borehole Artemia 52/80 65,0 HBNA Borehole Rotifers 0/103 0 HSWA Natural seawater Artemia 0/104 0

27 Granulomas in juvenile meagre Fish with granulomas Fish without granulomas Fish grown in borehole Fish grown in natural sea water (started with rotifers water (started with rotifers then Artemia) then Artemia) Fish grown in borehole water BUT fed only rotifers andnot Artemia during live feed stage Conclusions: 1. There is something in borehole water that triggers the onset of the granulomas 2. There is something in Rotifers that prevents the development of the disease

28 Rotifers vs Artemia enrichments Rotifers Artemia Moisture Crude Lipids Crude Ash Crude Fiber Phosphorus Vit. A Vit. D3 Vit. E Vit. C Antioxidants DHA/EPA Sum(n-3)HUFA 30% 67% 1% 1% 0.2% 1,500,00 IU/kg 150,000 IU/kg 3,600 mg/kg 800 mg/kg Ethoxyquin, BHA 2.5 min. 200 mg/g dwt Moisture Crude Lipids Crude Ash Crude Fiber Phosphorus Vit. A Vit. D3 Vit. E Vit. C Antioxidants DHA/EPA Sum(n-3)HUFA 30% 67% 1% 1% 0.2% 1,500,00 IU/kg 150,000 IU/kg 3,600 mg/kg 800 mg/kg Ethoxyquin, BHA 1 min. 400 mg/g dwt

29 Similar disease in fish Visceral granulomas in sea bream Visceral granulomas in brook trout Renal granulomas in turbot Some reports in cichlids and goldfish

30 Possible causes Magnesium deficiency High ratio of Ca/Mg or P/Mg High selenium Nephrocalcinosis (high CO 2 in water) Rancid fats Tyrosine metabolism Vitamin C deficiency Vitamin K deficiency

31 Conclusions Metabolic disorder Nutritional cause (Vitamin D, Vitamin K, Phosphorus) Environmental cause (ph, Carbon dioxide, Bicarbonates, Calcium) Check the live feeds enrichments ih Check water quality in hatcheries