Kelpfishes are known to change colors to adapt to their surroundings, they do this to hunt their prey, which is other small fish, crustaceans, and mollusks, or to avoid becoming prey to bigger fish. Kelpfish do not grow very big, only about 8-16 in (20-40cm), but Giant Kelpfish are known to grow up to 31 ft (80 cm) in length. The large Kelpfish species (Chironemus marmoratus), is called 'hiwihiwi' in New Zealand.