BEACHCOMBER

The THREE-COLOR TOP SHELL, also known as a calliostoma tricolor, is a small sea snail that grows to about a half-inch and has six whorls. A whorl is a complete revolution in a spiral, and it measures the shell’s growth. Whorls can be compared to growth rings in trees, but instead of growing out concentrically, they spiral down from the tip of the shell and get wider toward the bottom. This beautiful little shell is one of the rarer beachcombing finds. With a brownish-orange background, the shell has a dashed whiteand-purple band that follows the whorls around the shell. These mollusks can range from San Francisco to Northern Baja California, Mexico, and can be found in shallow intertidal waters as well as offshore to depths of 200 feet. This specimen was found near the tidepools in front of the Hotel del Coronado. ■

Class: Gastropoda Order: Trochida Family: Calliostomatidae Genus: Calliostoma Species: C. tricolor

Three-color top shell

CORONADOBEACHCOMBER

Coronado’s shoreline changes with the weather, tides and time of year. Coronadobeachcomber explores our shores daily on the beach or at the bay, paying attention to the interesting animals, shells and sea life. Follow @coronadobeachcomber on Instagram.