|
The use of aqueous
extracts of Vernonia amygdalina in the control of
saprolegniasis in Clarias gariepinus, a freshwater
fish
Ebele M. Ilondu1, Francis O. Arimoro2,3*
and Adjekawen P. Sodje3
1Department
of Botany, Delta State University, P.M.B. 1, Abraka,
Nigeria.
2Institute
for water Research, Rhodes University, P.O. Box 94,
Grahamstown 6140, South Africa.
3Department
of Animal and Environmental Biology, Delta State University,
P.M.B. 1, Abraka, Nigeria.
*Corresponding author. E-mail
fransarimoro@yahoo.com or
f.arimoro@ru.ac.za.
Tel: +27710535860.
Accepted 12 October, 2009 |
|
Saprolegniasis infection
causes severe damage to fish integument. To control this
fungal infection in the fish environment, Asteraceous plant
(Vernonia amygdalina) extract at varying
concentrations (50, 40, 30, 20%, control) was used to test
its potency in controlling the infection and to ascertain
its inhibitory capacity. The axenic culture of the test
fungus was maintained on PDA at 28oC. The rate of
the colony forming units was determined and the test inocula
adjusted to 1.5 X 105 spores per ml. The
Asteraceous plant extract generally depressed the growth of
the fungi and cleared the spores earlier noticed on the fish
integument. The potency of inhibition of the growth of
Saprolegnia increased with increase in concentration.
The control fish without the plant extract showed fluffy
tufts growing on their body after 28 days and they appeared
lethargic. This research hold great promise in elucidating
the potency of the plant extract (V. amygdalina) in
suppressing fungal growth in the integument of Clarias
gariepinus, a freshwater fish.
Key words:
Saprolegnia spp., Vernonia amygdalina, fish
integument, fish environment, fungi bait. |
