Monday, February 8, 2010

Rock Drill


The shell that you can see embedded in this lump of limestone, picked up on the beach at Seaburn last week, once contained the living mollusc known as a wrinked rock borer Hiatella arctica. This remarkable animal settled on the rock and then used the coarse ridges on the outside of its shell to bore its way into the soft limestone. There are five holes bored by separate animals in this rock and they've converted it into the geological equivalent of a lump of Swiss cheese. As rock borers grow their hole enlarges and once they are completely within the rock their future is quite literally set in stone - there's no way they can get out. When they die their shells are often trapped inside, so when I shook this rock it rattled. Piddocks have a very similar life style.........


This is the live animal, in a rock that's been cracked open, revealing the two red siphons that it uses to circulate water through its body. You can see that this individual is a good deal larger than the entrance hole on the left, through which it draws its supply of oxygenated water and food particles that it filters out from the water current.

15 comments:

  1. Fascinating Phil. I wonder how long it takes to drill the hole.

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  2. Will wonders never cease? What will nature think of next?

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  3. Interesting point John, I think I read somewhere that acid secretions from the tiny mollusc dissolve a pit in the limestone when it first settles, then after that it uses its 'drill' as it grows.......

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  4. It's a pretty amazing lifestyle, isn't it Ellen, but I guess it certainly gives the animal a measure of security...

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  5. Phil missed this first time around, I'd never heard of them. Nothing new there! It reminds me of an old radio programme. Describe something unbelievable then guess true or false. How do they reproduce I wonder?

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  6. Hi Adrian, they may be hermaphrodite. I think they produce swimming planktonic larvae that then settle and develop into a mini-verion of the adult mollusc...

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  7. Hello Phil. Just a note to say I enjoyed listening to The Living World, The Deer Park this morning. It was great to put a voice to your photo as well as enjoying an interesting tour.

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  8. Hi Phil

    Valentine Day morning and I wake up to the sound of Phil Gates in my ear! How romantic! Great piece on Radio 4's The Living Worl this morning - especially the bit about the left- and right-handed squirrels!

    Adam

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  9. Thanks John and Adam, they told me it was on but I didn't wake up until about 7.30, so listened on iPlayer. I think I talk too much and need to calm down a bit! The Deer Park is a very pleasant spot, if you are ever in this neck of the woods............

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  10. Hello Phil,
    I also enjoyed listening to you on Living World. Auckland Castle Deer Park has been googled and is firmly on the list of places to see or visit. I especially enjoyed the piece on the ants, as the hairy ants are also on my list from march onwards but also if you had read my blog recently, i enjoyed the bit about the Green Woodpeckers, having seen my first at Big Waters just last week. I think the fact that you "talk too much" is purely down to the enthusiasm you had on the programme and that comes over in your postings on your blogs. Look forward to the T.V. debut.
    Cheers
    John

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  11. Thanks John, as far as TV goes, my wife says I have a good face for radio.... The Bishop's Park is a very good spot for green woodpeckers (and dippers and kingfishers). Ant city is across the park over the bridge which I think is called Bishop Trevor's bridge, then along on your right, all along the south-facting slope.All the best, Phil

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  12. What have I been missing?! How come everyone else knows about you on the radio and I don't?! What stone have I been living under?! :O)

    Do you still write for the Wildlife Magazine, Phil? I don't buy it on a regular basis but I scoured through a copy the last time I was in W.H.Smiths and couldn't find you.

    "...a good face for radio." Hee-hee :D

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  13. Hi Lesley, these days on only write for the magazine on an occasional basis, not every month ....I'm doing something on blossom for the Easter edition of Countryfile magazine

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