Influence of continuous magnetic field exposure on water properties and subsequent effects on the growth performance, plasma biochemistry, nutritive value and liver histopathology of Jade PerchScortum barcooin a recirculating system

Abstract

A 150-days study was conducted on the continuous exposure of magnetized water at 0.00, 0.10, 0.15 and 0.20 Tesla (T) on quadruplicate treatments of Jade Perch Scortum barcoo juveniles in a recirculating system. Each replicate consisted of 18 fish with an average weight of 7.52 g over all treatments. The feeding efficiencies, growth, whole-body proximate plasma parameters, survival were measured and liver histopathology was observed. Our results show no significant improvement in water quality parameters, specific growth rate and body weight gain in this study. However, the best feed conversion ratio was recorded in fish exposed to 0.10, 0.15 and 0.20 T, which are significantly better than the control 0.00 T. Though survival was unaffected but plasma biochemistry and liver histopathology were affected even within the treatment. No liver, plasma or blood abnormalities were detected in fish exposed to 0.10 T and the control 0.00 T. But, one out of four livers from fish in the 0.15 T treatment showed a localized inflammatory response. These changes increased in the liver of fish exposed to 0.20 T, high AST and necrosis in this group is evidence of the liver cells damaged or been at risk. A significantly higher crude protein and lipid were noticed in the exposed fish compared with the control, 0.15 T had the highest crude protein and lipid while the control has the lowest. Based on the overall findings, on growth performance and looking at other factors like absence of any physiological disorder 0.10 T can be used as an effective and affordable technique improve the feeding efficiencies of Jade Perch. K E Y W O R D Scell count, Jade Perch, magnetic device, magnetic field, plasma biochemistry, water quality | INTRODUC TI ONMagnets have been used to improve various water quality parameters in tilapia culture and have been recognized as a new way to enhance some water quality parameters such as mineral solubility by reducing

Impacts of magnetic water treatment on water quality, feeding efficiency and growth performance of common carp in integrated recirculating aquaculture systems

“…Water temperature in the fish tanks was around the average of 24°C, which is within the optimum temperature of common carp foraging and growth (24 and 28 °C) reported byOyugi, et al (2012).The overall means of NH 4 -N, NO₂-N and NO 3 -N concentrations in fish tanks did not differ significantly (P>0.05) between the electromagnetic field system and the control system (Table2). The results of the present study are comparable with the findings of various authors(Krzemieniewski et al, 2004;Hassan et al, 2018a;Hassan et al, 2019) who found no changes in ammonium concentrations between the magnetic field system and the control system. However, the results of this study were in contrast with the findings obtained byRahman (2016), andHassan et al (2018b) who found a reduction in the ammonium concentrations of the magnetic treatments.…”

“…Moreover, the stocking density of fish was probably below the carrying capacity of these systems and did not reach the threshold at which survival rates would be affected. The survival rates of fish in the present study (100%) were higher than the 80.9% survival rate reported by Krzemieniewski et al (2004) Hassan et al (2019) for Jade Perch Scortum barcoo juveniles reared in a RAS under the exposure of different magnetic field intensities. The higher survival rate was achieved in the present study might be related to the duration of exposure, the field intensity and the variation in the sensitivity of different species.…”

“…The lower SGR was probably due to the higher initial stocking rate (2.3 kg/m 3 ) and/or the lower magnetic intensity (0.8 mT) used in the present study compared to those (0.213 kg/m 3 and 100-200 mT) used by Hassan et al (2018a). However, the SGRs of fish in the present study were higher than the 1.28-1.52%/day reported by Nofouzi et al (2017) for rainbow trout (Oncorhynchus mykiss) and the 1.60%/day obtained by Hassan et al (2019) for Jade Perch Scortum barcoo juveniles reared in a RAS under the exposure of different magnetic field intensities. Furthermore, the SGR of fish in the present study was also higher than the 1.03-1.06%/day and 0.9-1.21%/day reported for common carp reared in the RASs without magnetic treatment by Karakatsouli et al (2010) and Velichkova and Sirakov (2013) respectively.…”

“…Some authors reported that the magnetic water treatment had positive effects on fish growth (Hassan et al, 2018a;Nofouzi et al, 2017), and water quality of the systems (Krzemieniewski et al, 2003;Hassan and Rahman, 2016;Hassan et al, 2018b). However, other authors revealed no effect of using the magnetic water treatment on fish growth (Krzemieniewski et al, 2004;Hassan et al, 2019), and water quality (Krzemieniewski et al, 2004;Hassan et al, 2019). It appears that there is still considerable debate regarding the effects of magnetic water treatment on the growth of cultured species and water quality of rearing systems.…”

Impact of magnetic water treatment technology on water parameters, growth performance and blood parameters of the Nile Tilapia (Oreochromis niloticus)

“…However, the application of the magnetic treatment in aquaculture sector is still a new approach of several studies have been conducted to test the effect of magnetic field on aquaculture as Jamabo et al (2016); ) & Hassan et al (2019. Therefore, the purpose of this study was to evaluate the influence of using magnetic treated water and stocking density on water quality, growth performance, feed utilization, body composition and blood parameters of Nile Tilapia (Oreochromis nilolicus).…”