Abstract
A new species of the genus Monoliropus belonging to the family Caprellidae was collected from the Yellow Sea, Korea. The new species differs from Monoliropusagilis Mayer, 1903, Monoliropuskazemii Momtazi & Sari, 2013, and Triprotellaamica Arimoto, 1970 as follows: 1) gnathopod 1 subrectangular; 2) pereonites 2-3 with acute triangular processes anterolaterally; 3) mandibular palp, apical article with four simple setae subdistally. The new species is fully illustrated and extensively compared with related species. This is the first record of the genus Monoliropus from Korean waters. A key to Monoliropus species is also given.