The feeding mechanisms of two species in the tanaidacean family Kalliapseudidae, Kalliapseudes macsweenyi Drumm and Psammokalliapseudes granulosus Brum, are elucidated by comparing gut contents, mouthpart movements, and feeding behavior. Kalliapseudes macsweenyi filter-feeds and possesses plumose setae on the chelipeds, maxillipeds, and maxillae. When building its burrows, P. granulosus scrapes detritus off sand grains by using the comb setae on the maxillae. It suspension-feeds when settled in its burrows by trapping detritus on the antennular setae. Both species feed primarily on detritus. Diatoms were the second most abundant food item in the foregut of K. macsweenyi. Respiration and cleaning behavior are also compared.