Abstract:

Locally available nutrient materials (Cowdung, Soybean extracts and
Diammonium Phosphate (DAP)ZUREA inorganic fertilizer) were used to
prepare culture media for growing Chlorella spp. as
culture and compared to the commonly constituted Bold’s Basal Medium
(BBM) as a control. The production rate of Chlorella spp., the effect of
intrinsic ammonia and pH on culture performance, duration of culture cycle as
well as the differences in resultant fatty acid composition of the algae were
tested. The production rate of B. calycijlorus fed on this Chlorella grown
under the four media and the cost effectiveness of using each of the media
glass tanks, with 24hour illumination and aeration. Daily reading of
ammonia, pH and counts of algae cells/ml were carried out. On the other
hand, 10L plastic jerry cans, supplied with 24hour mild bubbling were found
suitable for rotifer culture. Daily changes in rotifer density (rotifers/ml) and
number of eggs carried per rotifer were recorded. Soybean extract attained the
highest density of Chlorella per ml, followed by Cowdung and DAP/UREA,
while BBM showed least performance. There was a notable positive effect of
pH on growth of Chlorella. On the other hand, ammonia did not have much
impact even at relatively high concentrations (236.095 mg I'1 in DAP/UREA).
Chlorella was found rich in various fatty acids but with a predominance of
polyunsaturated fatty acids (>40percent of Total Fatty Acids) in all media.
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were investigated. Experiments on algae culture were set in 25L rectangular
a food base for rotifer
Monounsaturated fatty acids (MUFAs) were recorded low (<5percent TFA)
for Cowdung, BBM and Soybean. DAP/UREA was superior for MUFAs and
found to have about half the quantity
of saturated. fatty acids (SFA) found in the other three media. The highest
number per ml of B. calyciflorus was found in the culture grown on
Cowdung. This culture also sustained a much healthier culture in terms of
production of eggs per rotifer and was also the most cost effective. Further
research on how these recorded performances translate into healthy larval fish
is required.
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HUFAs. Comparably, DAP/UREA w