Carbon, nitrogen and sulphur conten

Carbon, nitrogen and sulphur content of the soil are organic portions in the detritus and are important food sources. However, in humid areas with large amounts of detritus, most of the nitrogen and sulphur present is organic. Many crabs have been observed feeding on the sediment. The bacteria and meio-fauna present in the sediment may also be a good source of the nitrogen and sulphur for some macro-fauna species. Olafsson et al.have observwd positive correlation between crab biomass and soil nitrogen content which merit further attention in relation to the apparent importance of these soil organisms in the nutrition of common members of the crab fauna. Unfortunately, this study could not study the soil nitrogen contents due to lack of facilities, but positive correlations observed in abundance of all species of crabs with the soil carbon contents show their dependency on detritus based food web.