Impact of different lining substrata on biological and biochemical characteristics of the Nile Tilapia Oreochromis niloticus

Abstract

The effect of lining waterbodies on the growth performance and survival rate of the fish Oreochromis niloticus maintained in different lining substrata (cement, plastic and mud) and control (without lining) for 12 weeks was studied . It was found that there was no significant difference in the final mean size (length and weight) among the different groups; the fish length were 18.01±0.26, 17.73±0.15, 17.33±0.2 and 17.83±0.14 cm for cement, plastic, mud and control, respectively and weight (15.94±0.11, 15.73±0.2, 15.52±0.34 and 15.39±0.26 g for cement, plastic, mud and control respectively. The calculated condition factor (K-value) was 0.27±0.01, 0.28±0.0, 0.3±0.0 and 0.27±0.0 for fish maintained in cement, plastic, mud and control, respectively; which also wasn`t significantly differ among the study groups. In addition, determination of length increment (LI), the average weight gain (AWG), average daily weight gain (ADWG), the relative growth rate (RGR %) and specific growth rate (SGR %) of O. niloticus indicated that there is no significant differences obtained between the lining materials and control ones. In the same way, the biochemical analysis of the blood show no significant differences among fish groups maintained in different substrata. The electrophoretic patterns of tissue soluble-proteins extracted from the fish maintained in the tested lining media (mud, cement, and plastic) and control ones for a period of 12 weeks were also studied. It was found that the control group yielded 12 protein fractions of molecular masses between 165.24 and 12.34 kDa. Whereas, only 11 protein bands appeared in fish group maintained in cement substratum ranging from 162.62 to 12.15 kDa. Fish groups maintained in plastic and mud substratum obtained the same number of protein bands (14 bands) with molecular weight varied from 152.54 to 12.49 and from 165.24 to 12.34 kDa, respectively. Fish in cement group demonstrates the highest similarity indices with the two groups; control and mud with similarity index of 0.96 and 0.88, respectively. While the plastic fish groups show a similarity index of 0.69 and 0.79 with the same groups, respectively. It could be concluded that the application of lining the waterbodies (whatever the used material) hasn`t negative impact, on the growth performance, blood biochemical analysis and the protein profiles, comparing to the mud and control groups.