Snails. Phylum Mollusca
This is a common and familiar group of animals with unsegmented bodies encased in a single spiral, calcareous shell. Most are edible. For snails, the term length is equivalent to height.
Northern Abalone
Haliotis kamtschatkana
Flattened snail to 6 2/3 in. (17 cm) shell length. Row of holes along the shell margin. Brick-red, shell surface is corrugated. Edible, harvested commercially. Found at the lowest tides.
Black Abalone
Haliotis cracherodii
Shell length to over 8 in. (20 cm), with shell holes along the margin, usually 5 to 7 open. Exterior smooth; dark blue, green to black. Found high in the intertidal zone, Oregon to California.
Moon Snail
Polinices lewisii
Shell height to 3in. (8 cm), width to 5 in. (13 cm); globular shape. Most massive intertidal snail in this region. Mantle covers all of shell. Often submerged in sand, feeding on bivalves. Edible. The gelatinous egg case or collar shown is shaped and covered with sand as it is extruded from inside the shell. It may contain as many as half million eggs. The moon snail drills a hoe in the shell of its prey, usually a clam, by alternately rasping with a tooth-like radula and secreting chemicals to soften the shell.
Frilled (Dogwinkle) Whelk
Nucella (=Thais) lamellosa
To 3 in. (7.5 cm) long. Smooth to frilled shell. Color variable, white, orange to browns, sometimes banded. Stalked, yellow egg masses, sea oats, deposited in large clusters in the intertidal zone. Feeds on barnacles.
Ribbed (Dogwinkle) Whelk
Nucella (= Thais) emarginata
Short and plump shell to one in. (2.5 cm) long. Strongly developed spiral ribs, alternating heavy and light. Variable color: green, black, brown, or yellow, often with white bands. Feeds on barnacles.
Black Turban Snail
Tegula funebralis
Low cone of four rounded whorls, to one in. (2.5 cm) long, 1 1/5 in. (3 cm). Dull purplish-black with pearly interior. Abundant among intertidal rocks on exposed shores.
Leafy Hornmouth
Ceratostoma foliatum
To 4 in. (10 cm) long. Shell has extensive frills and a prominent tooth at the tapering end. White, gray, or tan. Lays flattened, yellow egg cases on shallow subtidal rocks. |
