Originally, ancient Greek poets used the Greek word Hippocampus to describe a half-horse, half-fish mythical god (hippos meaning horse and campus meaning sea monster) (Lally and Hough, 1999). This description poignantly describes their horse-like head positioned 90 degrees from its upright, armor-plated body, curved trunk, and prehensile tail ("Project Seahorse", 2003). Spotted seahorses can have an all black, grainy textured body pattern or a creamy, pale yellow body spotted with large, dark circles. These colors and patterns can be changed temporarily to match their immediate surroundings and act as a camouflage to avoid predators (Lourie et al., 1999).

Spotted seahorses are morphologically conservative and lack typical physical features of fishes such as pelvic and caudal fins, teeth, and a stomach (Lourie et al., 1999; "Project Seahorse", 2003). They also lack scales, having a layer of skin stretched over a series of bony plates instead which are visible as rings around the trunk ("Project Seahorse", 2003). These visible rings are useful in identifying various Hippocampus species.

Hippocampus fisheri can be distinguished from other seahorses by the presence of low, rounded bumps instead of the typical spines found along the body ("Project Seahorse", 2003). Spotted seahorses have a characteristically thick snout and deep head (Lourie et al., 2004). On either side of the deep head are eyes that can move independently, allowing them to maximize the search range when hunting for prey ("Project Seahorse", 2003). An adult H. kuda male can be distinguished from a female by the presence of a brooding pouch on his belly.

Seahorse lengths are measured by recording the distance from the tip of the tail to the top of the coronet, a cup-like depression found on top of the head. Adult lengths of H. kuda typically range between 7.0 and 17.0 cm (Capuli, Torres, and Froese, 2004). Adult weights, on the other hand, vary with the reproductive stages of both males and females ("Project Seahorse", 2003).

Range length: 7 to 17 cm.

Other Physical Features: ectothermic ; heterothermic ; bilateral symmetry

Sexual Dimorphism: sexes shaped differently