There is a myth that if you lick a sea anemone—you know, the thing that Nemo lived in—you’ll have good luck for seven years. Now, I come from a town where licking banana slugs is a sort of rite of passage, but I drew the line at marine life. I wasn’t above touching the squishy little invertebrates, though.
The first time I ever touched a sea anemone was in a tank with other organisms that children could feel to learn about the life in our local shores. It wouldn’t be until years later that I realized how important my time learning about the ocean was when I was young.
Even stranger than the sensation of touching a sea anemone was the sensation of touching the sea star. More familiar than the anemone, the sea star seemed like something I would know. I saw them on the rocks and had a pretty good idea of what they should feel like.
Instead of squishy and soft, like their appearance suggests, the little invertebrates were rough and incredibly solid. They felt like carved, spiky stones with slimy moss growing on them.
Now sea stars have no blood or brain. Instead, they have a water vascular system and a nerve net. These little critters move around by pumping water into their body and moving their thousands of tube feet to slowly scoot across the ocean floor.
Sea stars are closely related to sea urchins and sand dollars, all belonging to the phylum Echinodermata, which means “spiny-skinned.” Sea stars may look soft, but they have a spiny endoskeleton made of very small bones called ossicles. Some sea stars have very large spines, like the crown of thorns sea star. Sea stars can also have many more than five “rays,” or arms. Sun stars can have upwards of 20 arms and sometimes a five-rayed sea star will regenerate limbs that result in unusual numbers.
One of the strangest behaviors of the sea star has to be how it eats. Sea stars have an incomplete digestive system, which means they don’t have a mouth and an anus—they just have one hole that does both jobs. When sea stars come across some food, they push their stomachs out of their butt/mouth and begin to digest their food outside of their body. Not quite how you expected Patrick Star to chow down on a Krabby Patty, but that’s biology, baby.
Unfortunately, sea stars can’t survive out of salt water, so there are no star-shaped buds in the rivers and lakes of Wisconsin. They do thrive in most salt water environments, though, so sea stars are fairly common. An organism has to be resilient to survive in environments that go from violent waves to dry sun multiple times a day. A sea star’s hard body and strong tube feet provide an animal made to survive in the intertidal. Sea stars are also able to regenerate lost limbs, so if they suffer injury, they can bounce back.
A sea star’s life is not all easy, though. Unfortunately, food and water quality in some parts of the globe can cause sea stars to succumb to a condition called “sea star wasting disease.” This disease slows the regeneration process and can also cause deterioration of a sea star’s body.
Sea anemones are the soft bodied, slimy organisms that I expected the sea star to be. I wonder what sort of luck licking a sea star would bring. Regardless of the rigidity of their body or luck-bringing abilities, I don’t think I’ll be licking any marine organism any time soon.