Wednesday, 2 March 2016

ON THE ROAD SURPRISES - Part 4 - Going Underwater

Scuba diving is unpredictable and always full of surprises which is what keeps me going back for more. I’m off to the Maldives next week for a diving trip, so I’m going to leave you with some underwater surprises and I’ll see you when I return at the end of March.


The first time I bumped into a Decorator crab I didn't realise what I was looking at. We were diving the Lembeh Strait in North Sulawesi and I saw a sea urchin moving impossibly quickly on the sand. It was only when I swam closer that I realised the urchin was perched on a crab. 




These crabs have spikes on their eco-skeletons which enable them to attach sponges, seaweeds, algae - and in the case of the crabs I saw in Lembeh - sea urchins, onto their backs as a form of disguise. I've even seen a decorator crab with an unwieldy mess of dead coral on its back, but alas I haven't been able to unearth that particular photo from my files.





I think there's
 something rather endearing about these little critters and I'm looking forward to a wealth of diving surprises in the Maldives next week.



As a result of a question put to me (see the comments) I did further research and discovered that my 'decorator crabs' are in fact 'urchin crabs' which resemble decorator crabs. The big difference being: urchin crabs carry sea urchins and decorator crabs carry sponges, hydroids, bits of algae and other inert objects on their shells. 

This is a classic case of believing what a dive leader told me without thoroughly checking the facts - so slapped wrist to me - and big thanks to AW for asking the questions that prompted my research.

In answer to AW's question about the advantages: the sea urchins benefit from being carted around by the crabs because they are transported to new feeding grounds. 




9 comments:

  1. Fascinating, Susan. Does this harm the creatures they attach or is it to mutual advantage?

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  2. That's an interesting question, Ann. I don't believe it harms the sea urchin, but I'm not sure if it actually benefits it either. Hmm, I'll have to research this and get back to you! :)

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  3. There are some weird things living in the sea, aren't there?

    At first glance, that sea urchin looked like a sweet chestnut. I suppose they both have spines for the same reasons.

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  4. Don't get me started on 'weird', Patsy! The underwater world is a constant source of astonishment to me. I'll be posting more of the strange and wacky creatures in our oceans when I return from my dive trip. :)

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  5. Pretty little guy! Enjoy your trip, Susan :) I'm joking of course- how could you not?

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    1. Thanks, Jo - I intend to enjoy the dive trip providing I don't go down with a cold or ear infection (it happens!).

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  6. Pretty little guy! Enjoy your trip, Susan :) I'm joking of course- how could you not?

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  7. It's a whole other world, isn't it? Have all those strange aliens ever inspired you to write sci-fi?
    Have a great trip!

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  8. Thanks, Linda. No, I couldn't write sci-fi to save my life - but one of my dive articles opened with the line: 'It looked like something from the movie, The Abyss...' :)

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