The significance of multiple bacterial infections in lutjanus sp. in Malaysian marine cage culture system
The epizootiology of disease problems in Lutjanus erythropterus (Crimson snapper) was conducted in Pulau Langkawi Kedah, the northern state of Peninsular Malaysia, for a period of eight months until harvest due to reported continuous mortality of about 30% after two months introduction, incurring hi...
| Main Authors: | , , , , |
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| Format: | Conference or Workshop Item |
| Language: | English English English |
| Published: |
2015
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| Online Access: | http://irep.iium.edu.my/46909/ http://irep.iium.edu.my/46909/1/WA2015BluePages.pdf http://irep.iium.edu.my/46909/5/World_Aquaculture_THE_SIGNIFICANCE_OF_MULTIPLE_BACTERIAL_INFECTIONS_IN_Lutjanus_sp._IN_MALAYSIAN_MARINE_CAGE_CULTURE_SYSTEM.jpg http://irep.iium.edu.my/46909/14/46909_the_significance_of_multiple_bacterial.pdf |
| Summary: | The epizootiology of disease problems in Lutjanus erythropterus (Crimson snapper) was conducted in Pulau Langkawi Kedah, the northern state of Peninsular Malaysia, for a period of eight months until harvest due to reported continuous mortality of about 30% after two months introduction, incurring high economic loss. Infected fish was morbid, discoloured with haemorrhagic ulcers in dorsal areas and severe necrosis of caudal region. Monthly sampling revealed multiple Vibrio infections with variable prevalence rate during grow-out stage as shown in Fig.1.
Necropsy revealed abnormal liver, with cases of severe whitish nodules in kidney and spleen. The caudal peduncle area was soft and fluffy to touch, releasing yellowish exudates when cut. Histopathological diagnosis of the kidney, spleen and muscle using Grocott and Modified Ziehl Nelsen staining revealed red, long, thin and filamentous organisms in the granulomatous lesions suggestive of nocardiosis shown in Fig. 2. Further sampling of the Lutjanus sp that were above 250g(5thmonth), showed exopthalmus with watery brain, in which case Streptococcus iniae was isolated for three consecutive months. Vibriosis was prevalent throughout the culture period with concurrent infection of V. vulnificus and V. alginolyticus during the later period nearing harvesting. The study has shown that multiple bacterial infections are prevalent throughout culture period infecting at different level and stages of fish growth causing continuous mortality. High economic loss is expected with the recorded pattern of disease infections and thus knowing the source of fish with better treatment regime for effective control is needed for sustainable healthy production. Fig.1. Multiple Vibrio sp. infection in Lutjanus erythropterus (Crimson Snapper)
Fig.2. Nocardia spp. Infection in Lutjanus erythropterus (Crimson Snapper)
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