Secret life of starfish

Dr Liam Herringshaw (Canada) In every sea, in every ocean,Beasts of freakish locomotionProwl the substrate, seeking preyTo feast on in a monstrous way. Dinner is served. On a plate before you, there is a delicious roast chicken. However, the bird is larger than your head and you have no hands or teeth you can break it up with, let alone a knife and fork to use. How are you going to eat it? Are you going to push one half of your stomach out through your mouth, smothering the chicken in digestive juices to dissolve it, then haul your stomach back into place, slurping up the nutritious broth as you go? No? Well you are obviously not a starfish! Members of the class Asteroidea, to give them their proper name, are among the most familiar of all sea creatures, the five-fingered favourites of many a seaside publicity brochure. Yet, even a cursory investigation of their biology, ecology and evolutionary history reveals the familiarity to be a deception. These icons of the intertidal are about as strange as life on Earth gets. If their feeding habits weren’t weird enough, asteroids have a skeleton made of crystals, possess extraordinary powers of regeneration and move around on a system of tiny hydraulic tentacles. And they don’t even have a brain. What they do have is membership of an exclusive club: the Echinodermata or ‘hedgehog-skins’. If you have ever seen footage of crown-of-thorns sea stars chomping their way across the Great Barrier Reef, you … Read More

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Collecting fossils on the Jurassic Coast: The Eype Starfish Bed

Richard Edmonds (UK) Between Seatown and Eype, on the West Dorset coast (part of the Dorset and East Devon Coast World Heritage Site), there is a remarkable layer of rock known as the Eype Starfish Bed. This is famous for exquisitely brittle starfish (brittlestars) fossils that are usually preserved on the soft, sandy underside of a thick sandstone unit within the Middle Lias. It has been speculated that they became buried during a single storm or possibly even a tsunami event, about 185Ma. Fig. 1. A block containing starfish showing a failed extraction next to the hammer, stone saw extraction on the right and centre and also attempts with a cordless powerdrill at the top. On the outside of the block, the sandstone is relatively soft, but becomes progressively harder the deeper you go. It follows that specimens are highly vulnerable to erosion and rapidly damaged or destroyed if left in the rock, on the beach. The bed itself is located high in the cliffs and, in places, its sharp base is clearly visible. This means that it is only possible to examine and collect specimens from ex situ, fallen blocks. Fortunately, occasional cliff falls bring these large blocks down to beach level and storms also uncover material that has been buried in the talus at the base of the cliff. Fig. 2. The Starfish Bed is located high up in the cliffs (just above the spring line), with large fallen blocks below. There is only one way to collect … Read More

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