World Aquaculture Singapore 2022

November 29 - December 2, 2022

Singapore

IMPROVEMENT IN IMMUNE RESPONSE AND DISEASE RESISTANCE OF Cyprinus carpio AGAINST Aeromonas hydrophila THROUGH A DIET OF CHITIN AND CHITOSAN

Tan Jia Wen* and Liu Chun Hung

Diploma in Veterinary Technology, School of Applied Science,
Temasek Polytechnic, 21 Tampines Avenue 1, Singapore 529757

1704007b@student.tp.edu.sg

 



Cyprinus carpio is one of the oldest domesticated aquatic species for food. Farmed C. carpio production was nearly 14 percent of the total global freshwater aquaculture production in 2002. Aeromonas hydrophila is one of the most common zoonotic pathogens found in the carp farms. In this study we added immunostimulants, chitin, and chitosan into the feed of C. carpio to enhance its immune response to other antigens. 1% chitin, 0.5% chitin, 0.5% chitosan, 1% chitosan and control were added to respective feed and 2 months feeding trial was held before the immunity was tested.  Besides immune parameters such as lysozyme and respiratory burst were tested in the study, concentration of expressed mx gene in individual fish were measured using quantitative polymerase chain reaction. Blood smears were made to count the number of white blood cells and results were compared to the reference range. Challenge test with lethal dose 50 using A. hydrophila showed that fishes fed with 1% chitin and 1% chitosan have close to 50% of the mortality rate in the 5 days of observation period. While the rest have a mortality rate of 25% through the 5 days observation period. However, within the first 24 hours of observation, the mortality rate of fishes fed with 0.5% chitin and 0.5% chitosan was 70% less than the control. Throughout the whole feeding trial, fishes fed with 0.5% chitosan showed the highest growth rate within the set ups while fishes fed with 0.5% chitin showed the lowest growth rate followed by control.