International Journal of Aquaculture, 2024, Vol.14, No.1, 9-19 http://www.aquapublisher.com/index.php/ija 12 composition of MUFAs was observed at 8 °C on the 14th day (34.71 ± 8.96) with Palmitoleic acid (16:1n7), Oleic acid (18:1n9), and vaccenic acid (18:1n7) dominating. Table 1 Relative proportions of fatty acids (% of total FAs; mean ± SE, n=3) of the Thermocyclop sp. were stored at varying temperatures: 4, 8, and 12 °C after the 7th and 14th day of the experiment Fatty Acids 4 °C 8oC 12oC Day7 Day14 Day7 Day 14 Day7 Day14 14:0 2.43±0.32 2.07±0.69 1.84±0.40 1.22±0.52 3.80±1.32 2.39±1.15 16:0 38.48±0.89 41.01±4.18 26.39±0.56 35.26±3.54 37.45±3.75 39.16±2.75 18:0 15.49±0.57 20.31±2.89 9.31±0.15 14.72±1.18 12.23±0.43 18.49±2.78 20:0 1.41±0.11 nd 0.61±0.14 nd 0.28±0.05 nd 22:00 0.47±0.13 0.95±0.18 nd 0.71±0.13 0.29±0.04 1.04±0.07 24:0 0.73±0.14 1.33±0.23 nd nd nd nd Total SFAs 59.00±2.16 65.66±8.18 38.15±1.25 51.92±5.37 54.04±5.58 61.08±6.76 14:1n5 2.11±0.75 2.98±1.91 0.74±0.24 0.91±0.27 0.88±0.17 1.81±1.27 16:1n7 8.20±0.09 5.61±1.20 9.72±0.24 7.18±1.75 9.40±1.47 6.79±1.67 18:1n9 5.07±0.56 5.35±0.28 11.45±0.71 7.44±2.22 5.65±0.58 5.18±0.81 18:1n7 4.94±0.24 6.48±0.93 7.63±0.00 6.84±2.15 5.35±0.24 6.12±1.11 20:1n9 0.67±0.07 nd 0.13±0.03 2.13±0.29 1.71±0.10 nd 22:1n9 0.41±0.14 0.73±0.06 nd 0.82±0.10 nd 1.39±0.12 24:1n9 1.60±0.21 2.92±0.72 nd 1.04±0.24 0.83±0.12 1.90±0.54 Total MUFAs 32.99±3.13 25.89±5.43 33.54±2.02 34.71±8.96 32.99±4.02 33.31±6.71 18:2n6 1.73±0.22 1.66±0.10 11.19±0.71 3.36±0.63 2.40±0.65 1.53±0.45 18:3n3 1.28±0.23 1.59±0.11 6.58±0.42 2.96±1.12 2.32±0.17 0.52±0.09 20:2n6 0.75±0.42 0.71±0.05 0.62±0.07 0.81±0.25 2.49±0.36 0.97±0.31 20:3n3 1.60±0.15 nd 2.53±0.28 0.76±0.07 nd 1.76±0.15 20:4n6 1.32±0.28 2.60±0.33 nd 2.40±0.15 3.43±0.61 nd 20:5n3 0.61±0.07 1.01±0.01 4.54±0.53 1.35±0.29 1.25±0.37 0.83±0.61 22:6n3 0.71±0.12 0.88±0.16 3.48±0.21 1.73±0.71 1.08±0.15 nd Total PUFAs 8.01±1.48 8.45±0.76 28.95±2.21 13.38±3.21 12.97±2.31 5.61±1.62 Notes: Not detected (nd), Saturated fatty acids (SFAs), Monounsaturated fatty acids (MUFAs), and Polyunsaturated fatty acids (PUFAs) The total PUFAs were highest on the 7th day at 8 °C (28.95 ± 2.21%). Among the total FAs, Linoleic acid (18:2n6) and Linolenic acid (18:3n3) were dominating. Notably, Arachidonic acid (20:4n6) and Docosahexaenoic acid (22:6n3) were not detected at 12 °C on the 14th day. Amongst the essential fatty acids: Arachidonic acid (AA; 20:4n6), Linoleic acid (LA;18:2n6), Linolenic acid (LNA;18:3n3), Eicosapentaenoic acid (EPA; 20:5n3) and Docosahexaenoic acid (DHA; 22:6n3), no significant difference was observed across the storage temperatures (P = 0.81) on the 7th and 14th day (P= 0.87). Additionally, there was no significant interaction effect of temperature and day on fatty acid composition (P=0.88). 2 Discussion Successful viable storage and packaging of live Thermocyclop sp. is an essential requirement for their utilization as alternatives to the presently used Artemia in fish hatcheries. Live feeds provide a more nutritionally rich food and one that can be utilized by small-mouthed fishes/ larvae. However, use of the live feeds is limited by many challenges in defining appropriate cultural and storage conditions. Therefore, the present study investigated the effect of storage conditions on the survival and fatty acids of Cyclopoid-copepods as a starter diet for the African catfish larvae. 2.1 Effects of storage temperatures onThermocyclop sp. Generally, there was a gradual decrease in the survival of Thermocyclop sp. with time at different temperatures. This decrease could be due to starvation since these organisms were not fed throughout the experimental period (Koussoroplis et al., 2014; Hansen et al., 2020). Starvation of organisms lowers the amount of energy required to
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