Taxonomy

Rarity

The strawberry anemone is the pink and orange carpet on the shaded rock walls of a Southern California reef, and it is common through the entire range, from British Columbia to San Martin Island in Baja California. It lives on rock walls, under ledges and around wharf pilings, from the low intertidal down to about 312 feet, which covers every depth a diver on this site will ever reach.

Nobody harvests it and no California rule is written for the species, so it falls under the general invertebrate limit of 35 of any one species per day, with take of all invertebrates prohibited inside state marine reserves and restricted in state marine parks and conservation areas. That limit is an odd fit here for reasons the next section makes clear. The International Union for Conservation of Nature has never assessed the species.

Seasonality

Location

Strawberry anemones want rock and shade. The positions named for them are rock walls, the undersides of ledges, and the sides of wharf pilings, on exposed rocky shore, protected rocky shore, inside bays and inside kelp forests. That is a consistent preference for surfaces the sun does not hit directly, which fits an animal that gets nothing from sunlight and everything from what the current brings it.

The individual animal is tiny. A single polyp is about half an inch across and 4 tenths of an inch tall, stretching to a bit over an inch when it hangs down off a vertical wall. What a diver actually sees is never 1 of them. It is a dense sheet of hundreds or thousands, packed tightly enough that the rock disappears underneath.

The color is bright and it varies more than the common name suggests: red, pink, orange, lavender, pale blue, crimson and purple all occur. The bodies are pink, red or orange, and the tentacles are white or clear with distinct white knobs on the tips. Those club-tipped tentacles are the identification. No true sea anemone on this coast has them.

Deep Dive

Start with the name, because the name is wrong. True sea anemones belong to the order Actiniaria, and the giant green anemone on this site is one of them. The strawberry anemone belongs to the order Corallimorpharia, a separate group whose members sit closer to the stony corals than to the anemones they resemble. Corallimorphs look like anemones that have decided not to build a skeleton, and the resemblance is close enough that everyone including this page calls them anemones anyway. The 2 animals share a class and nothing below it. The common name was applied to the appearance rather than the animal, and it has never been corrected because it is genuinely useful shorthand.

The color pattern on the rock is the best thing about this species, because it can be read. Strawberry anemones reproduce mainly by splitting themselves, producing clones, and color turns out to be under genetic control. So every polyp in a patch of a given color is the same individual, copied. Where 2 patches of different color meet, the visible boundary between them is a boundary between 2 separate genetic animals, each one a colony built from a single founder that landed on that rock and started dividing. A diver looking at a mottled wall of pink and orange is looking at a map of who got there first.

That is also where the fight happens. Secondary accounts describe strawberry anemones as aggressively territorial, killing neighboring anemones and corals and taking the space by filling it with copies of themselves. The agency description is milder, noting only that they form dense aggregations and will grow over other organisms, so this page reports the aggressive version as the secondary claim it is. Either way the outcome on the rock is the same: a colony that spreads by cloning does not need to out-compete anything cleverly, it just needs to keep dividing into whatever space opens up.

Sex has not been abandoned entirely. Alongside the constant splitting, the species spawns sexually, and the spawning is synchronized and peaks in early December. Splitting produces single-sexed clones, so an entire patch of one color is all male or all female, which is what makes a synchronized release across a reef of many separate clones worth the trouble.

Feeding is passive and specific. The white club-tipped tentacles catch copepods and other small drifting crustaceans, including the larval stages, and that is the whole income. This animal has no photosynthetic partners doing any of the work, unlike the giant green anemone, which houses algae in its tissue and gets a subsidy from sunlight. A strawberry anemone in the dark under a ledge is exactly where it wants to be.

The regulation is worth 1 last note for the oddity of it. California's general invertebrate rule allows 35 of any one species per day. For a clonal animal whose individual is smaller than a fingernail, 35 polyps is a patch about the size of a coin, and all 35 would very likely be the same genetic animal anyway. The rule was not written with this species in mind, which is a fair description of most invertebrate regulation on this coast.

Where to Find Them

Beaches whose habitats match this species

Matched by habitat: a beach is listed when its biome tags overlap this species' biomes.