Positive solution and its asymptotic behaviour of stochastic functional Kolmogorov-type system

In general, population systems are often subject to environmental noise. This paper considers the stochastic functional Kolmogorov-type system dx(t) = diag(x(1)(t), ... , x(n)(t))[f(x(t))dt + g(x(t))dw(t)]. Under the traditionally diagonally dominant condition, we study existence and uniqueness of the global positive solution of this stochastic system, and its asymptotic bound properties and moment average boundedness in time. These properties are natural requirements from the biological point of view. As the special cases, we also discuss some stochastic Lotka-Volterra systems.