Taxonomy

Rarity

Abundance rates how many are in suitable habitat. Find difficulty rates how hard it is to locate one on a daylight snorkel or freedive through 50 ft. A higher find score means a harder search. The rarity category also reflects the kind of encounter; it is not an average of the 2 scores.

Seasonality

Location

The species lives from Fort Bragg in Mendocino County south to Puerto San Bartolome in Baja California Sur, Mexico, though it is uncommon north of Point Conception, Santa Barbara. Records run from the low intertidal zone to about 180 feet. It lives on rocky reef and on sand and mud, usually where the water moves little.

Given a choice, it takes hard bottom. California Sea Grant reports that it avoids mud and areas with heavy freshwater runoff and will move off soft sand. A study at Santa Catalina Island found warty sea cucumbers on rock rubble 7 times as numerous as those on sand, though 27% smaller. The bottom matters for feeding: the debris on the rubble held 3 times as much organic material per gram, and the animals on sand had to swallow 8 times as much sediment.

Deep Dive

A sea cucumber is an echinoderm, a relative of sea stars and sea urchins. Its skeleton has been reduced to tiny hard pieces scattered through the body wall. The warty sea cucumber is chestnut brown to yellow, covered in soft projections with black tips. On the bottom it stretches to 12 to 16 inches, but the length is a poor guide, because the animal can contract and can take on water. Measured contracted, the largest on record was 9.5 inches long and 3.5 inches wide, and the heaviest weighed about 1.6 pounds.

It eats the bottom. The animal feeds on detritus, the fine layer of dead organic material and tiny organisms that settles on sand and rock. Sticky tentacles around the mouth gather it up, and the sea cucumber takes in only the top few millimeters of sediment. As it feeds it stirs and softens the seafloor, which recycles organic matter and makes habitat for other animals.

Its defenses are unusual. A sea cucumber can expel its own internal organs to escape a predator and then grow them back. The warty sea cucumber also does something like this every year on its own schedule. California Sea Grant reports that in October and November it sheds its digestive and breathing organs and stops feeding for about 4 weeks while they regrow. Its reproductive organs are absorbed in September and October and rebuilt by January. The state's 2001 status report adds that the animal loses about 25% of its body weight in the process. Reported predators include sea stars, sea otters, crabs, kelp greenling and California sheephead, though predation on adults is rarely seen and is thought to be low.

The sexes are separate, and the animals reproduce by releasing eggs and sperm into the water. Spawning runs from March to July, almost all of it shallower than 100 feet and most shallower than 60 feet, and spawning groups form in the shallows each spring. The larvae drift for about 28 days before settling under rocks or in kelp holdfasts. California Sea Grant reports that an animal begins reproducing at about 2 years old. No one knows how long the species lives, because there is no method for telling a sea cucumber's age.

Most of the catch is boiled, dried and shipped to China, Hong Kong, Taiwan and Korea, where sea cucumber is a delicacy. A small market for live animals has grown in the United States, selling to sushi and specialty restaurants. Sea Grant describes the meat as having little taste of its own and taking on the flavor of whatever it is cooked with. Recreational take is rare: the state reports receiving only about 5 questions from sport divers about taking any sea cucumber since 2012.

The rules allow it in a narrow way. California sets no limit of its own for the species, so the general limit of 35 invertebrates per person per day applies, with no size limit and no closed season. Sea cucumbers are not on the short list of animals that may be taken from tidepools and the intertidal zone, so none may be taken between the high tide line and 1,000 feet seaward of the low tide line. Take of all invertebrates is prohibited inside state marine reserves, and north of Yankee Point in Monterey County scuba may not be used to take them. The commercial fishery closes from March 1 to June 14 to protect the spawning groups.

Where to Find Them

Researched habitat and range candidates

These locations have suitable habitat within the species range. An assignment is a possible encounter, not a confirmed sighting at every beach. Season, depth, and local conditions still matter. Historical habitat without present-day evidence is excluded.