With their upright position, prehensile tail, and horse-like head set at right angles to the body, seahorses are some of the most unusual looking of all fishes (4). Instead of having scales, as most other fish do, seahorses have a layer of skin stretched over a bony armour that is arranged into a series of rings (5) (6). Swimming is powered by the rapidly oscillating dorsal fin, and they steer using the fins on either side of the body (the pectoral fins) (5). The lined seahorse is a large seahorse with a deep chest (4) (6). Colouration varies from ash-grey, orange, brown, yellow and red to black, and brown individuals are usually paler on their front (5) (6). The body is often marked with a characteristic pattern of pearly white lines following the contour of the neck, for which the species is named, as well as tiny white dots on the tail and a darker or paler 'saddle' across the back (5) (6).