March 25

The weather is sunny and warm, as we explore the tide pools near Cabrillo Beach. Soon, in one of the pools, I notice some tiny snail shells are crawling around. These shells are occupied by Hermit Crabs (stock photo). These decapods lack a shell, so they use an empty one from another species. Contrary to popular belief, these crabs don’t kill the snails in whose shells they make their homes. They’re actually able to smell dead or dying snails, which they will occupy. Competition for such shells can be fierce including fighting to the death in pursuit of a shell. And, as they grow, Hermit Crabs must seek out new shells in which to live. Nearby, I spot a lifeless, Two-spot Octopus with a 7-inch mantel. As with other octopi, this one is a soft bodied mollusk with eight tentacles. Like its relatives, it can change skin color and texture when hunting, hiding, mating, or responding to other stimuli. After a year of life, a fertilized female will lay an average of 70,000 eggs in a den and siphon cool water over the nest; she often dies during this period due to starvation and exhaustion. In a small puddle, I see a colorful, five-inch diameter Sunburst Anemone. Nearby, I see more of them concealed by shell fragments and other particles that adhere to the column, which folds into an encrusted oval. This appearance may serve as camouflage from predators as well as protection from solar radiation and desiccation. In another small pool, I spot some Calcareous Red Seaweed while on a nearby exposed rock some are bleached white by the sunlight. Next, I see a few one-inch, Black Turban Snails. This species has some smart escape mechanisms. If attacked by a predatory snail, it will climb on to the top of its shell. If attacked on a slope, it detaches its foot and rolls downward and away. Once the soft snail's body has perished, their unoccupied shells are a favorite of hermit crabs. Hopping over rocks, from pool to pool, I observe a mass of ¼-inch Acorn Barnacles and a cluster of Gooseneck Barnacles. Known to stick hard to the undersides of vessels, to other sea life, to each other, and to pretty much anything they come in contact with, barnacles secrete a fast-curing cement that is among the most powerful natural glues known — the glue is so strong that researchers are trying to figure out how it can be used commercially. Turning around and making my way back to the car, I come upon a four-inch, ornate shell of a Sea Urchin. While alive, this creature projects stiff spines that act as stingers (stock photo). After death, the spines break off exposing the shell.

Waves retreat

Ebb the tide

Shallow pools

Creatures reside

Exposed rocks

Edge of the ocean

Anemones

Shells in motion

Sand and sea

Predator and prey

Clinging green

Nature’s array

 

D. DeGraaf