About this time of year our local waters seem to be alive with s-e-x, er I mean reproduction. The male garibaldi are establishing their nests for the season, young giant kelp sporophytes are appearing on the rocks, and the Kellet's whelks are mating. Certainly spring is in the air. This is a great time of year for a marine voyeur, er I mean biologist, since there is so much interesting behavior to observe underwater.
Kellet's whelks are large snails found from Monterey Bay to Isla Asuncion off Baja California. They frequent kelp beds, rocky reefs and soft bottoms from the low intertidal where they are rare down to about 230 feet. Their white or gray shells are heavy and strongly sculptured. The shell may reach lengths of 7" making them one of the larger snails in our waters. A 3" long animal may be 7-8 years old and they are reported to live a long time. The shell may be covered with encrusting algae and invertebrates. The snail's body is yellow with black and white mottling.
Most people think of snails as slow moving animals that feed on plant life, especially in our gardens. This species is carnivorous feeding on dead or injured animals it encounters. I have seen Kellet's whelks feeding on other snails such as the Tegula and wavy top snails. They are said to invade lobster traps, killing and feeding on the trapped animals. In turn they may be fed on by starfish and octopi, and possibly sheephead although the thick shells are difficult to crush. The shells of these snails are even found in Native American kitchen middens suggesting they were been eaten by our early island residents.
Although these snails are reported to mate in March or April, they seem to be mating a bit earlier this year possibly due to the reasonably "water" temperatures in the Park. Mating behavior in the sea is often triggered by warmer water temperatures, which can accelerate the growth of eggs and larvae. I heard from dive buddies in the San Diego area that they were mating there at about the same time as those in our waters.
Groups of up to two dozen may be seen together on the bottom when they spawn. Up to 1,000 individual eggs are laid in flattened capsules attached to rocks and up to 85 capsules may be laid by a single individual. More than one Kellet whelk may lay eggs on the same substrate. Often they will cover a rock and I've even seen them laid on an outboard engine at 65 feet in the Dive Park. Maybe the parent expected a bit more "get up and go." The planktonic larvae emerge in about a month and drift with the currents until they settle to the bottom in a new location.
Although the Kellet whelk may move faster than your average snail when pursuing food, I can't say the same for their mating speed. I sat on the bottom and watched about 10 of them for nearly 15 minutes waiting for some telltale motion. Not a sign. They certainly must have great stamina!
© 2004 Dr. Bill Bushing. Watch the "Dive Dry with Dr. Bill" underwater videos on Catalina Cable TV channel 49, 10:00 AM and 5:00 PM weekdays.
Top- Kellet whelk on top of rocky reef; Kellet whelk
feeding on Tegula snail;
Bottom- several Kellet whelks in a mating group, Kellet whelk laying egg capsules
This document maintained by
Dr. Bill Bushing.
Material © 2003 Star Thrower Educational Multimedia