Appearance
The fifteen-spined stickleback is an elongated fish with a long slender snout, an elongated caudal peduncle about one third of the total length, and a fan-like rounded caudal fin. The anterior dorsal fin consists of a series of fourteen to fifteen small, widely separated spines. The posterior dorsal fin and the anal fin are aligned and are similar in size and shape and located immediately anterior to the caudal peduncle. The pelvic fins consist of spines. This fish is brownish-yellow with indistinct dark markings and a silvery belly. It grows to a maximum size of 22 centimetres (8.7 in), but the usual size range is 8 to 15 cm (3 to 6 in).

