Dogwinkles (class Gastropoda)

Description: Dogwinkles are a type of marine snail commonly found at Haystack Rock. Two varieties typically spotted by visitors include the northern striped dogwinkle (Nucella ostrina) and the frilled dogwinkle (Nucella lamellosa). Their names accurately describe their appearance: the northern striped dogwinkle usually has dark brown or black stripes spiraling around its shell, and the frilled dogwinkle usually has frilled edges that curl up from its shell. Northern striped dogwinkles can reach lengths of 3 centimeters and frilled dogwinkles grow to be between 5-8 centimeters long. However, both of these dogwinkle species can vary greatly in color, thickness, banding, and shape, so identifying these mollusks can be tricky.

Habitat: Both of these species can be found in the intertidal zone clinging onto rocks. Along the Pacific Coast of North America, they can both be found from Alaska down to California. 

Diet: Like other mollusk relatives, dogwinkles have a radula (a structure similar to a tongue made of teeth) that they use to feed. However, while other marine snails feed on algae, dogwinkles are predatory and feed on barnacles. To get inside of a barnacle, dogwinkles drill a hole into the barnacle’s shell by using their radula and then they use their long proboscis (an similar to a straw) to suck out the flesh. Frilled dogwinkles will also eat mussels through this same process. 

Tide Pool Tidbits:

• Dense groups of dogwinkle eggs can be found covering patches of rock in the spring and summer. These oval-shaped eggs are usually a pale white or yellow color; sometimes, the eggs are referred to as “sea oats” because of their resemblance.

References: Central Coast Biodiversity webpages on northern striped dogwinkles and frilled dogwinkles