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Research Journal of the University of Ruhuna, Sri Lanka- Rohana 13, 2021
There may be an unknown factor influencing the growth of fish such as initial

weight which may have an essential vigor for growth performance. In this

experiment, initial weight of fish in control tanks was higher than in other
experimental tanks. So, it may be the vigor for growth performance of fish in control

tanks. But, mean relative growth rates in fish tested in both T3 treated and control

tanks have been obtained higher growth rates than other treatments. So, initial length
and weight do not affect the fish growth in control tanks. Present observation

indicates that small fish are more palatable for a control diet. And it may be the
other reason for higher growth in fish in the control tanks. Also, these fish highly

prefer garlic-containing fish diet to other medicinal plant ingredients-containing fish
diets.

Comparison of mean values of water quality parameters indicates that only pH is

significantly different in experimental tanks. Water quality in treatment tanks has

not been changed by feeds with medicinal plants through the experimentation. It
elucidate that medicinal plant feeds do not alter water quality, and they can be given

to fish with feed without harming to the water quality. In the present experiment,

same pellet sizes were used, and study found that the pellet size do not affect the
water quality. Fish in control and garlic-treated tanks have obtained higher growth

rates than others. The palatability of feed by fish may affect for this results. The
study confirms that medicinal plant feeds can be given to fish without harming to

quality of the water.

Conclusions

The present study concludes that fish in control and garlic treated tanks shows

higher growth rates than other fish in the experiment. Small fish are more palatable
for both control and garlic-containing fish diets and affect fish growth in the

experiment and, medicinal plant feeds can be given to fish without harming to the
water quality. Study recommends that the experiment should be continued for a

longer period to observe the any changes in water quality parameters and the growth

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