###### Abstract
They noted that heat transfer rate and melting time are respectively increased and reduced with a rise in nanoparticle volume fraction. Magnetized nanofluids constitute yet another development in nanoscale fluidics. These nanomaterials exploit suspended magnetite nanoparticles which effectively render the nanofluid to be electrically-conducting. To simulate the dynamics of magnetic nanofluids, magnetohydrodynamic (MHD) models are required. The nanofluid is therefore more intelligent and operates more as a smart fluid allowing the manipulation of flow and thermal characteristics with externally applied magnetic fields [PERSON] et al. [27]. The fusion of nanofluid and magnetohydrodynamics produces many interesting combined effects including Lorentzian drag effects, secondary flow (Hall currents), electromagnetic induction, damping, ferrofluidics, levitation phenomena, Ohmic dissipation, magnetic torque, ionslip and Maxwell displacement currents. Numerous studies of magnetized nanofluids have been communicated in manufacturing, biomedical, energy and chemical engineering systems. [PERSON] et al. [28] used the Crank-Nicholson finite difference technique to study transient mixed convection MHD nanofluid flow from an exponentially stretching sheet in permeable materials. [PERSON] et al. [29] obtained MAPLE quadrature solutions for time-dependent slip hydromagnetic nanofluid flow in porous media. [PERSON] et al. [30] computed chemical reaction effects on natural convection magnetized nanofluid boundary layer flows. [PERSON] et al. [31] investigated nanoparticle shape (brick, cylinder and platelet) effects on hydromagnetic pumping and heat transfer in nanofluids in a deformable conduit as a model of magnetic-targeted drug delivery. Further studies include [PERSON] et al. [32] who employed a finite element code for simulating dissipative magnetic nanofluid inclined Sakiadis flows; [PERSON] et al. [33], who used a B-spline collocation algorithm for unsteady nanofluid orthopedic lubrication flows; and [PERSON] et al. [34] who evaluated both chemical reaction and viscous heating effects in hydromagnetic nanofluid Sakiadis flow. Several authors have also examined melting effects in magneto-nanofluid transport. [PERSON] et al. [35] computed magnetohydrodynamic effects on melting heat transfer for the case of boundary layer stagnation-point. This study was for an electrically conducting nanofluid moving toward a stretching surface as well as heat source/sink. Other melting magneto-nanofluid dynamics investigations include [PERSON] et al. [36] with non-Newtonian and radiative effects and [PERSON] et al. [37] with radiation and stagnation point flow effects in carbon-water nanofluid. Bioconvection involves the motion of micro-organisms under special conditions [38]. For such flows, as heavier micro-organisms sink, they are replaced by up swimming micro-organisms. The process causes a macroscopic motion (convection). The mechanism driving up-swimming is closely linked to the species of micro-organisms [39]. Common micro-organisms include oxytactic bacteria and gyrotactic algae. Oxytactic bacteria are an oxygen-consuming microorganism, and gyrotactic algae are linked to gravitational torque. It is only in the past three decades that bioconvectionhas gained much attention [40]. The current focus on \"green technologies\" is a major impetus behind the idea of using bioconvection micro-organism mechanisms in certain engineering systems. Bioconvection is interesting since the driving up-swimming is known to be associated with the microorganism species. Nano-bioconvection fuel cells are, in particular, stimulating great interest in recent years [41; 42]. Many studies have confirmed that the accumulation of microorganisms in the upper portion of the fluid layer causes a top-heavy density stratification, instability then sets in and causes the microorganism to fall. \"Return up\" swimming microorganisms maintain this pattern.