Various factors have been suggested as regulating the availability of detritus to detritivores, e.g., particle-size and microbial dynamics, nutritional composition of detritus per se, and chemical inhibitors/ enhancers. These factors might vary in importance depending on detritus source: fecal pellets, vascular plants, or seaweed-derived detritus. We review the literature to evaluate the above factors and suggest that future research on detritus should consider regulatory mechanisms which depend on detritus type.