SciSun: Sea-ing Stars   Leave a comment

At the Oscar Awards celebration last week, all the biggest stars were in attendance: Action Hero stars; dramatic stars; comedy stars; musical stars; and even stars you didn’t know were stars, but they must be because they were there (or they snuck in). But one star we didn’t see was the star of California surf and beach (no, not the stars who play Lifeguards by the Bay) – the Sea Star.

Sea Stars (class Asteroidea) – until recently known as ‘starfish’ (they must have changed their name when they became famous), usually don’t attend award ceremonies, or live in huge mansions in the California hills, or frequent exclusive restaurants (well, unless they’re on the menu – but they don’t like to think about that). It’s not that they’re avoiding the paparazzi, it’s just that not many people think about these littleechinoderms who aren’t fish yet form a very important role in the in helping keep our seashores and oceans clean and healthy. While their roles might not be as broad as, say, an Oscar winner, they’re one of the supporting players that tie together the whole story. Kind of like that actor you see in almost every movie, but you never know his name even though you like him.

So, you ask, what are these echinoderms anyway? And why is everyone so up in arms about them? One reason, might actually be their arms. While humans, and most animals must rely on just two arms, echinos usually have five arms, radiating outward from a central body. This is referred to as radial symmetry – something like a pizza that’s been cut into five pieces – and is very different from the bilateral symmetry that most animals share. For us, and most other animals, one half of our body is more or less like the other half (comparing the left side, to right. From front to back each of us are very different. Particularly if you just ate a big meal). So If you look at yourself in a mirror, you’ll see that both sides of your body – left and right – are more or less the same. But most echinoderms – and sea stars in particular – don’t see a mirror image reflection of themselves when looking in a mirror – they see two pairs of arms on each side, and a fifth arm all alone. Actually, they probably don’t see that at all because they have very simple eyes that seem to recognize light and dark only, and not distinct shapes. Plus there aren’t many mirrors in the ocean and what mirrors there are, usually are taken by mermaids.

Although they are animals like each of us, echinoderms live very different lives than any of us could ever imagine: They don’t have any blood, but they do have a water-vascular circulatory system that consists of sea water-filled channels throughout their body that transports oxygen (like blood does, in most animals), and helps them feed and move. They have no brain, as we would describe it, and a very primitive nervous system, yet can show surprising intelligence and the ability to learn simple behaviors like the location of objects and avoiding obstacles. Living only in marine environments (meaning the ocean – not a branch of the military), they usually have one eye-type organ on each leg, so can ‘see’ all around them (which would actually be pretty useful if they were US Marine observers); and if one leg is lost through a predator or accident, over time a new leg grows in its place and the animal is as good as new. Sometimes the lost leg canregenerate an entirely new sea star, just from the portion of that one leg!

 

Most Sea Stars have five legs.  Others are just show-offs.

Most Sea Stars have five legs. Others are just show-offs.

Despite their unusual, and to most animals almost alien characteristics, Sea Stars are dying in alarming numbers off both the West and East Coasts. Along the Pacific Coast of California, Sea Star Wasting Disease is leading to what some say is the largest sea star die-off ever seen, in some places leaving none of the animals alive and no one knows what, or why, or how this is happening. It’s believed changes in water temperature; or shift in water nutrients and chemistry; or pollution, fertilizer and waste run-off from our own gardens and lawns could be to blame; but the results are sea stars turning into ‘goo’, a slimy, unrecognizable mass that’s almost something out of a sci-fi movie. Of course this is bad news for the stars; but as these echinoderms are among the most important detritus feeders in a tidal ecosystem – eating dead animals and keeping the water and seashore free of disease and contaminants – the loss of the sea star could lead to disastrous results for fish and sea birds and sea mammals and everything else that depends upon the ocean – including humans.

It’s easy to ignore some of the brightest stars, even if they are right in front of us. No matter how exceptional or insignificant they might appear, one day every star finds the role for which he or she will always be remembered and recognized. For the little sea star, their role might not be obvious but it’s what helps keep everything in balance. By making good choices and remembering everything has a part to play, each of us can help keep the environment healthy and on every trip to the seashore we can look forward to seeing, Stars.

http://oceanservice.noaa.gov/facts/starfish.html

http://www.eeb.ucsc.edu/pacificrockyintertidal/data-products/sea-star-wasting/updates.html

^^^

Michonne Says:  In the Flower-time I loose hair, and then it grows back in the Cold-time. And one time I broke a claw and it grew back. But I’ve never known anyone who grew back an arm. I’d like to see that. But I don’t want it to happen to me. What if I grew back too many, and I wouldn’t know what to do with the extra?

Posted March 9, 2014 by ECOVIA eco-adventure® in SciSun

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