author(s)
Minal S Wagde, Subodh K Sharma, Bhanu K Sharma

abstract
The present study was aimed to assess the impact of dietary natural b-carotene sources viz., Carrot and Spinach on the growth of an ornamental fish swordtail (Xiphophorus hellerii). Experimental swordtails were cultured for 35 days in aquarium tanks. They were fed with experimental diets prepared with two natural vegetable sources viz. Carrot (Daucus carota) and Spinach (Spinacia oleracea) to supply 20, 25 and 30 mg of b-carotene individually per 100 g of diet. There were 6 experimental diets for each b-carotene sources and 1 common control diet (devoid of b-carotene). The proximate analysis of the experimental diet was also carried out. The water quality in the entire aquarium was maintained for assessing the growth. The fish were fed once a day at the rate of 3% of their body weight and the diets were readjusted after assessment of increase in fish weight every week. The net weight gain in experimental duration was highest in fish fed with Spinacia oleracea (0.73 g) followed by Daucus carota (0.54 g) where the fish were fed with 30 mg of b-carotene per 100 g of basal diet and lowest in control tank (0.29 g). The maximum specific growth rate (SGR) and gross conversion efficiency (GCE) were noticed in T₆ i.e. 1.11 and 0.88 respectively. From this study, it could be concluded that the natural β-carotene incorporated feed as growth enhancer can be prepared at a lower cost using the cheaply available sources.