The major diseases to which barramundi are susceptible are listed in the following table.
In some cases antibiotics and other pharmaceuticals have been used in treatment but their inclusion in this table does not imply an FAO recommendation.
In some cases antibiotics and other pharmaceuticals have been used in treatment but their inclusion in this table does not imply an FAO recommendation.
| DISEASE | AGENT | TYPE | SYNDROME | MEASURES |
|---|---|---|---|---|
| Viral nervous necrosis (VNN) | Lates calcarifer encephalitisvirus (LcEV) – a betanodavirus | Virus | Pale or dark colouration; erratic swimming behaviour; spiral swimming; bloating; 'fainting'; extensive vacuolation of the brain & spinal cord; generally encountered during hatchery phase | Screening of broodstock; low larval rearing densities; optimal larval nutrition; improved broodstock nutrition; improved hatchery hygiene |
| Lymphocystis | Lymphocystis virus | Virus | Wart-like growths on skin & fins; generally only fatal if infection severe & associated with very poor environmental conditions | Removal of infected fish; improved environment |
| Vibriosis | Vibrio harveyi; Vibrio spp. | Bacteria | Marine fish with darkening; lethargy; anorexia; reddened ulcerations on body; reddened abdominal fluid; associated with nursery systems, poor environment & skin trauma | Improved environment; antibiotic treatment |
| Bacterial haemorrhagic septicaemia | Aeromonas hydrophila; AAeromonas sobria; Aeromonas caviae; Aeromonasspp.; Pseudomonassp. | Bacteria | Freshwater fish with irregular reddened skin ulcerations; lethargy; anorexia; reddened abdominal fluid; pale gills; associated with poor environment & skin trauma | Improved environment; antibiotic treatment |
| Integumentary bacteriosis | Aeromonas sobria; Aeromonas hydrophila; Vibrio harveyi; Vibrio alginolyticus | Bacteria | Irregular reddened skin ulcerations; loss of scales; associated with poor environment & skin trauma | Improved environment; increased water exchange |
| Streptococcosis | Streptococcus iniae | Bacterium | Darkened fish; anorexia; pale gills; reddened abdominal fluid; reddened abdominal organs & inner wall | Antibiotic treatment; vaccination |
| Columnaris disease | Flavobacterium columnare; Flavobacterium johnsoniae; & Flavobacteriumsp. (gliding forms) in freshwater Tenacibaculum marinimum in seawater | Bacteria | Pale skin patches on dorsal surface behind dorsal fin & on caudal peduncle; lethargy; most commonly occurs in nursery phase; in older juveniles a mouth form with erosion of skin around upper & lower jaws has been seen; associated with overstocking, tank rearing, poor hygiene & skin trauma | Treatment in potassium permanganate or copper baths may help in early disease; antibiotic treatment |
| Bacterial gill disease | Various bacteria,Flavobacteriumspp., Cytophagaspp. | Bacteria | Swimming at water surface; gulping; rapid opercular movement; excess mucus on gills; white patches on gills; most commonly occurs in nursery phase | Improve water quality; treatment with salinity reversal, potassium permanganate or quaternary ammonium baths; increase water exchange; reduce stocking density |
| Bacterial peritonitis | Various Gram-negative & Gram-positive bacteria including Vibrio harveyi &Aeromonas hydrophila | Bacteria | Darkened fish; lethargy; swollen abdomen; adhesions & bad smelling fluid in abdomen; abdominal fistulas; more common in recirculation systems | Cull affected fish; antibiotic treatment |
| Bacterial enteritis | Various Gram-negative bacteria | Bacteria | Acute disease in intensive larval rearing systems; anorexia; pin heads; darkened fish & death | Cull affected larval batch |
| Fin and tail rot | Aeromonasspp.;Pseudomonasspp.; Vibriospp.;Flavobacteriumspp.; Cytophagaspp. | Bacteria | Erosion of soft tissue in fins and tail; may extend to involve entire tail & caudal peduncle | Improve environment; reduce stocking density |
| Epitheliocystis | Epitheliocystis organism – aChlamydia | Bacterium | Swimming at water surface; rapid opercular movements; disease rare but seen in marine fish & in recirculation systems | None known |
| White spot | Ichthyophthirius multifiliis in freshwater Cryptocaryon irritans in marine | Protozoa | 'Flashing'; rubbing skin on surfaces; anorexia; swimming at water surface; white spots on skin & fins | Treatment with salinity reversal, formalin baths or combinations; treatment in copper bath for marine fish |
| Chilodonelliasis | Chilodonellaspp.;Chilodonella hexasticha | Protozoa | Swimming at water surface; rapid opercula movement; flared opercula; seen in poor environmental conditions & in weakened fish | Treatment with salt, formalin or potassium permanganate bath or combinations |
| Trichodiniasis | Trichodinacomplex spp. | Protozoa | Swimming at water surface; rapid opercular movements; excess gill mucus; typically follows cold water temperatures, high organic loads & high stocking densities | Increase water exchange; treatment with salt or formalin bath |
| Ichthyobodosis (costiasis) | Ichthyobodo necator | Protozoa | 'Flashing'; rubbing skin on surfaces; opaque patches on skin; raised scales; swimming at water surface; rapid opercular movements; flared opercula | Treatment with salinity reversal; formalin or potassium permanganate bath |
| Piscinoodiniasis | Piscinoodiniumsp. | Protozoa | Found in freshwater: In young fish opaque patches or a greenish discolouration of the skin; patches of skin lifting of surface & ulcers In older fish rapid opercular movements; excess gill mucus; dark green gill colour | Treatment with salt bath |
| Amyloodiniasis | Amyloodinium ocellatum | Protozoa | Found in marine conditions: In young fish opaque patches or a green discolouration of the skin; patches of skin lifting of surface & ulcersIn older fish rapid opercular movements; excess gill mucus; dark green gill colour More common in broodstock and in raceways; associated with low water temperatures or rapid drops in temperature | Treatment with freshwater, copper, formalin or hydrogen peroxide bath |
| Red sore disease | Epistylis sp. | Protozoa | Skin ulcers in freshwater pond fish; raised fluffy surface & secondary bacterial infections | Reduce organic levels in water; treatment with formalin bath |
| Gill fluke | Diplectanumsp.; Dactylogyrus sp. | Monogean trematodes | Rapid opercular movements; anorexia; white areas on gills | Treatment with salinity reversal, formalin, organo-phosphate or praziquantel bath |
| Skin fluke | Neobenedinia melleni;Gyrodactylusspp. | Monogean trematodes | Marine fish with opaque cornea; white patches on skin; skin ulcers; associated with high salinity & cool water temperatures | Treatment in freshwater or hydrogen peroxide bath |
| Myxosporidiosis | Henneguya sp.;Kudoa sp. | Spore-forming protozoa | Disease uncommon but histologically spore cysts seen in gill filaments (Henneguya sp.) & brain (Kudoa sp.) | None known |
| Microsporidiosis | Pleistophora sp. | Spore-forming protozoa | Raised lumps on skin; soft white nodules in muscle | None known |
| Integumentary mycosis | Saprolegniaspp.; Achlyaspp. | Fungi | Raised, fluffy growths on skin & fins; associated with low water temperatures & skin trauma | Salinity reversal and formalin baths; do not handle fish when water temperatures low |
| Branchiomycosis | Brachiomycessp.; Achlya spp. | Fungi | Swimming at water surface; rapid opercular movements; white & red patches (mottled appearance) on gills; associated with cold water temperatures & high organic loads | No treatment known; reduce organic load & increase water exchange |
| Fish louse | Argulus sp. | Copepod | Disc-shaped parasite visible on skin; red foci; darkening | Treatment in organophosphate bath |
| Anchor worm | Lernaea sp. | Copepod | Thin body of female parasite visible on skin with small red ulcer where parasite penetrates skin | Treatment in organophosphate bath |
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