Title : The possible agents causing a low survival rate of the marine rabbitfish larvae in artificial reproduction
Abstract:
Rabbitfish is a tropical marine species in Vietnam, known as the specific species in Tam Giang Cau Hai lagoons. In hatcheries, the survival rate of this species is relatively low, especially from day 8 to day 15 after hatching. Several possible reasons that caused the dramatic decrease in the survival rate of rabbitfish (Siganus guttatus) larvae even the fish already changing successfully from endogenous to exogenous feeders on days 3 and 4 are malformations, lacking digestive enzymes for exogenous feed and infection of agents like Vibrio and Aeromonas. By analysing the Chitinase enzyme activity and other enzymes: cellulose, β-glucanase, xylanase and phytase, protease and lipase are all unsufficient in the intestine of S. guttatus larvae, we accidentally found the genome of the Aeromonas bacteria which is known as freshwater pathogens in freshwater fishes. The 16S rRNA gene was operated for studying taxonomic and phylogenetic relationships at the species level. The first finding of Aeromonas from the intestinal microflora of S. guttatus at length 22 – 23 mm and weight 144 – 170 mg poses a particular problem how a freshwater Aeromonas presented in the gut of a marine species, what role of Aeromonas might have related to the interaction with other intestinal microorganisms and the low survival rate of S. guttutus in artificial reproduction that will be interested by the audience and marine scientists.
What will the audience learn from your presentation?
? The scientists could be interested in opening up a new research direction on freshwater pathogensis in marine species.
? The audience could investigate the present of Aeromonas in marine species and the impact of this microorganism to fishes.
? Further studies could investigate the survival rate of fish larvae and juveniles related to the Aeromonas pathogensis, and how to increase the survival rate in artificial reproduction.
