Adult Macrobrachium lanchesteri were exposed for a 4-day period in laboratory conditions to a range of copper (Cu), cadmium (Cd), zinc (Zn) and lead (Pb) concentrations. Mortality was assessed and median lethal times (LT₅₀) and concentrations (LC₅₀) were calculated. At the end of the 4-day period, live prawns were used to determine bioconcentration of the metals. LT₅₀ and LC₅₀ increased with the decrease in mean exposure concentrations and times, respectively, for all metals. LC₅₀s for 96 hours for Cu, Cd, Zn and Pb were 32.3, 7.0, 525.1 and 35.0 µg/L, respectively. Cu, Cd, Zn and Pb bioconcentration in M. lanchesteri increases with exposure to increasing concentrations and Cd was the most toxic to M. lanchesteri, followed by Pb, Cu and Zn. Comparison of LC₅₀ values for metals for this species with those for other freshwater crustacean organisms reveals that M. lanchesteri is equally or more sensitive to heavy metals than most other tested crustaceans.
This study analyzed the levels of cadmium (Cd), copper (Cu), and zinc (Zn) by the flame atomic absorption spectrophotometer (FAAS), in the muscle tissues, exoskeletons, and gills from freshwater prawn (Macrobrachium rosenbergii) (n = 20) harvested from natural habitat in Kerang River, Malaysia on 25th November 2015. Significant increase of the metals level in muscle tissue and gill (r > 0.70, p
This study reports the comprehensive comparative information of two different detoxification enzymes such as glutathione S-transferases (GSTs) delta and kappa from freshwater giant prawn Macrobrachium rosenbergii (designated as MrGSTD and MrGSTK) by investigating their in-silico characters and mRNA modulation against various biotic and abiotic oxidative stressors. The physico-chemical properties of these cDNA and their polypeptide structure were analyzed using various bioinformatics program. The analysis indicated the variation in size of the polypeptides, presence or absence of domains and motifs and structure. Homology and phylogenetic analysis revealed that MrGSTD shared maximum identity (83%) with crustaceans GST delta, whereas MrGSTK fell in arthropods GST kappa. It is interesting to note that MrGSTD and MrGSTK shared only 21% identity; it indicated their structural difference. Structural analysis indicated that MrGSTD to be canonical dimer like shape and MrGSTK appeared to be butterfly dimer like shape, in spite of four β-sheets being conserved in both GSTs. Tissue specific gene expression analysis showed that both MrGSTD and MrGSTK are highly expressed in immune organs such as haemocyte and hepatopancreas, respectively. To understand the role of mRNA modulation of MrGSTD and MrGSTK, the prawns were inducted with oxidative stressors such as bacteria (Vibrio harveyi), virus [white spot syndrome virus (WSSV)] and heavy metal, cadmium (Cd). The analysis revealed an interesting fact that both MrGSTD and MrGSTK showed higher (P