cycloid scale Scale that is smooth-edged, round or oval and composed of acellular dermal bone lacking small spines on the posterior exposed edge. (from http://www.briancoad.com/Dictionary/introduction.htm). TAO:0002285 Typical of many teleosts. Some cycloid scales may have a serrated margin and are then termed spinoid scales. (from http://www.briancoad.com/Dictionary/introduction.htm). teleost_anatomy scale