Effect of different organic acids on survival of larvae and control of water microflora in milkfish (Chanos chanos) hatchery system
Effect of different organic acids on survival of larvae and control of water microflora in milkfish (Chanos chanos) hatchery system
Date
2018
Authors
Kumar, N.R.
Kumar, P.P.
Siddaiah, G.M.
Murugadas, V.
Basha, K.A.
Sivaraman, G.K.
Prasad, M.M.
Journal Title
Journal ISSN
Volume Title
Publisher
Society of Fisheries Technologists (India), Cochin
Abstract
This study reports the use of organic acids (acetic,
malic, formic and citric) in fish larval rearing
systems for survival and controlling the microflora
of rearing water. The milk fish (Chanos chanos) larvae
was treated for 10, 15, 30 and 60 min with seven
concentrations (%) viz., 1, 0.2, 0.1, 0.075, 0.05, 0.025
and 0.02 of organic acids respectively. The percentage
survival was zero (1, 0.2, and 0.1% conc) for all
the organic acid at various time periods. The
effective concentrations for treating fish larvae are
0.05, 0.05, 0.025 and 0.075% concentrations of acetic,
malic, formic and citric acid, respectively where
100% survival was observed. Similarly, when the
larval rearing water was treated with different
concentrations of same organic acids and time
period, complete inhibition of microbial flora was
observed (1, 0.2 and 0.1% conc) for all organic acids
at various time periods. However, at concentrations
less than 0.1%, total bacterial count (TBC) and
presumptive Vibrio count (PVC) were found in the
range of 3.19 to 5.75 and 2.22 to 3.58 log 10
cfu ml-1. In contrast, TBC and PVC in control group
were found in the range of 6.37 to 6.90 and 4.35 to
4.74 log 10 cfu ml-1. The acid treatment with
concentrations of 0.075, 0.05 and 0.025 except formic
acid at 0.025, 0.020 significantly (p<0.05) improved
the survival rates of fish larvae and reduced both
TBC and PVC in larval rearing water. The present
findings strongly recommend the use of organic acids for treating fish larvae for improved survival
and also for reducing pathogenic bacterial load from
larval rearing waters.
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Citation
Fishery Technology 55(2):128-137