The muscles on the sides of the abdomen. Use this tag when the oblique muscles are well-developed and noticeable. The external oblique muscle is one of the outermost abdominal muscles, extending from the lower half of the ribs around and down to the pelvis ending where the groin begins. Common names to describe developed obliques are "fish gills" (upper) and the Adonis or Apollo's Belt (lower). While it is possible for females to develop this muscle, it is more visible and far more common in males due to the differences in bone structure and distribution of body fat.