Adult common seadragons are an orange/reddish colour, with yellow and purple markings; they have small leaf-like appendages that resemble kelp fronds providing camouflage and a number of short spines for protection. Males have narrower bodies and are darker than females. Seadragons have a long dorsal fin along the back and small pectoral fins on either side of the neck, which provide balance. Common seadragons can reach 45 cm (18 in) in length. Southern versions tend to be darker in colour than Eastern ones.