The focus of study is on the dynamics of interaction between commensal and host species in an aquatic ecological system with harvesting, diffusion and stochastic attributes. All possible equilibrium points of the system are identified. The stability both local and global of the commensal-host system has been examined around the interior equilibrium point. The possibility of existence of bio-economic equilibrium is discussed. The optimal harvesting levels are identified. The role of diffusion parameters on stability is analysed. We provided the analytical estimates of the population intensities of fluctuations of the system with Gaussian white noise perturbations by applying Fourier transform technique. Some numerical simulations are also carried out to make lawful the analysis. © RJPT All right reserved.