In this paper we consider a general deterministic model consisting of a micro-organism pool living on detritus of mangrove litter and its invertebrate predators. Here the growth rate of micro-organism is assumed in the general form and Holling type-II functional response of the invertebrate predators is incorporated. We find a globally attracting steady state for some parameter values, and a stable limit cycle for some other parameter values. It is also shown that there exists Hopf–Andronov bifurcation with respect to the control parameters. It is found that the specific growth rate and the food conversion efficiency rate of invertebrate predator governs the dynamics of such a model.