On Exhibit: Sandy Shore & Aviary
crabs, worms, clams and small fishes
to 5.5 feet (1.7 m)
skates and rays; Family: Rhinobatidae
northern California to the Gulf of California
A long, pointed snout and a guitar-shaped body give the shovelnose guitarfish its common name. Compressed from belly to back, guitarfish bodies are attuned to life on the sand. Colors that range from olive to sandy brown on their upper body and white below help shovelnose guitarfish blend into their sandy seafloor habitat. They live on sandy seafloors in bays, seagrass beds and estuaries, and usually in less than 40 feet (12 m) of water.
A mouth located on the bottom of the disc is well placed for eating bottom dwelling prey, but breathing through it would destroy a guitarfish's delicate gills. Instead, guitarfish pump water in through holes (spiracles) on top of their heads, over the gills, and out through gill openings on the bottom of the disc.
Guitarfish lie in ambush buried in the sand with only their eyes sticking out, waiting for an unwary crab or flatfish to wander by. Suddenly the sand erupts, and the guitarfish gulps down its meal. At night, they leave the sand to actively cruise the seafloor to feed on crabs, worms, clams and, perhaps, fishes.
Until recently, guitarfish were discarded from commercial catches. But today, they are kept as part of a steady, minor fishery.
The genus name—Rhinobatis—is a combination of the Greek word "rhine" meaning shark and the Latin word "batis" meaning ray. Guitarfish look like sharks and swim using their sharklike tail rather than flipping their pectoral fins as most rays do.
Shovelnose guitarfish are commonly found in nearby Elkhorn Slough during fall and early winter.
Shovelnose guitarfish crunch crabs and other shelled invertebrates with their pebble-like teeth. These rays are harmless, although a guitarfish bit a diver who interrupted the courting activity of a male guitarfish.
All female rays give live birth. The nursery and spawning grounds are in the bays of southern California and Baja, where females arrive in spring and stay until early summer when they give birth to their pups. Males arrive soon after to mate and then both males and females leave the area.
This ancient ray has been playing it flat for over 100 million years.