Abstract:
Fish is essential for food security and nutrition. The nutritional quality of the fish is affected by
age, sex, food availability, environment, and season. The estimation of these contents aids in
ensuring their dietary needs and commercial specifications. The current study aimed to estimate
the proximate composition and mineral content of four fish species in the Koka reservoir. Fish
samples were randomly collected from Koka reservoir at landing sites, kept in an icebox at 4oC
and immediately transported to the Ambo University Biology Department Laboratory. Prior to
determining the proximate and mineral composition, the fillet parts of the fish were immediately
taken and stored in the refrigerator. An experimental correlational design that involved the
quantitative data collection approach was used in this study. The proximate composition and
mineral contents of the samples were determined following the standard procedures of the
Association of Official Analytical Chemists. C. carpio and L. intermedius had the highest mean
moisture (80.79±2.44%) and protein (17.38±1.61 mg/100g) contents, but C. gariepinus had the
highest crude fat content (0.84±0.31g/100g) and ash contents (3.06±0.60 g/100g). In other
words, there was no significant difference in moisture content among the three size groups of all
fishes (p>0.05), except for C. carpio (p<0.05), but protein and carbohydrate content did
(p<0.05). The fat content of all fishes varied between sizes (p<0.05), except for C. carpio
(p>0.05), but only O. niloticus and C. carpio showed a significant difference in ash
contents (p<0.05), all mineral contents varied significantly among the fish species (p<0.05)
except for copper (p>0.05) C. carpio had the highest mean calcium (103.33 mg/100g) and
magnesium (412.67 mg/100g) contents, but the mean iron (256.83 mg/100g), zinc
(15.5mg/100g), manganese (3.8 mg/kg), and copper (3.26mg/100g) were found to be highest in
O. niloticus. Except for Cu, the results revealed a significant difference in mineral content among
fish species (p<0.05). All mineral contents differed significantly between the different size
groups of O. niloticus and C. carpio (p<0.05). In general, the proximate and mineral contents
recorded in the fish species are moderate and promising enough to support people's nutritional
security. Therefore, it is pivotal to cultivate these fish species to improve their nutritional quality
and further contribute to food security.
