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Marine Life & Conservation

Construction Crews – who digs those holes in the sand?

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Gliders, Mantis Shrimps and Gorgeous Prawns… Mouth filled with sand, the Pennant Glider emerged from his hole and expelled the sand onto the growing pile at the edge of the hole. His partner darted into the hole and emerged with another mouthful of sand that he too spat onto the pile. Their burrow was formed in a crevice in the sandy rubble bottom and they had simply taken up residence in it and kept it clear. But the varying currents kept filling it, shells rolled into it, and they maintained it by suction and jet expulsion. This simple method of clearing a hole is used by many fish species as a sort of undersea vacuum cleaning system.

Not all such undersea residences are natural however. Some of the most impressive burrows on the reef are made by the Mantis Shrimp. They have immensely powerful front claws, and some species are able to break a camera lens with a blow. They can easily dig out a substantial hole in the sand on the reef, and Mantis shrimp are largely responsible for the more impressive holes on the reef.

The Giant Mantis creates a fully lined, superbly constructed burrow for himself in soft sand. These holes seem to be lined with a cement made with spittle and bits of sea-grass, and they are extremely strongly built.

Smaller holes become the home of Commensual Partnerships between a prawn and a goby.

The Goby can see and hunt but can’t dig, and the prawn can dig but is blind and can’t hunt. So they team up, and form a mutually beneficial relationship.

The goby’s task is to find food, and the prawn shares his bounty. The goby acts as the attack alarm, and is incredibly sensitive to movement and light. Few people know to wait and watch their interaction but it can be hilarious.

The prawn’s job is to dig and shovel the debris out of their home as it accumulates, depositing it in the right place by following the spine of the Goby with a feeler. The goby moves to point in the direction where the prawn must shovel the next pile of sand. This works very well until an extra goby arrives, or another shrimp joins the team.

We watched for half an hour as a pair of industrious shrimp both shovelled sand, small coral pieces and bits of shell out of the hole under the direction of a rather harassed-looking goby. The problem came when they both shoved at the same long coral piece, and it got stuck in the mouth of the hole. Looking baffled, his line of retreat closed, the goby darted off and hid under a rock. The two prawns shoved vigorously until the mouth of the hole ruptured, and a full day’s work dropped back into the hole. The goby came home, and you almost hear him muttering with rage as he haughtily dived through the debris to seek sanctuary below.

Where there are two gobies and only one shrimp sharing a hole, it is even funnier, as the two gobies point the prawn in opposite directions. We watched a completely paranoid prawn shoving a pile of sand and shells out of the hole as directed by the first goby and then pushing the same pile of sand back into the hole by following the spine of the second goby. The hole never changed, and we left before the prawn gave up.

Look out for holes in quiet corners on rubble or sandy bottoms, duck behind a rock, and watch. It’s worth it.


Words: Jill Holloway

Pics: David Holloway

Copyright: Ocean Spirit

www.osdiving.com

Jill Holloway lives in Mauritius and at Sodwana Bay Isimangaliso Wetland Park in South Africa. A PADI qualified Nitrox diver with over 1,500 dives, she is a passionate observer and preserver of the marine environment, and has a database of over 35,000 fish pics and hundreds of Gopro videos on fish behaviour, which she shares with her readers.

Marine Life & Conservation

Shark Trust launches Oceanic 31 Shark Art Auction

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After a two-year tour of UK art galleries, community spaces and aquariums, the Shark Trust’s acclaimed Oceanic31 exhibition takes its final bow at the Royal Geographical Society later this month. And the unique collection of artwork, depicting 31 species of oceanic sharks and rays, donated by 31 artists, is now open for bids from art lovers and shark enthusiasts. The online auction, launched today, will close on the 7th December at 8pm (BST). The money raised will support the Shark Trust Oceanics Programme.

People can now bid on 27 of the artworks by visiting this website:

https://superstars-auctions.com/sharktrustauction

It is a chance to own a beautiful piece of original art and to support the Shark Trust. The timing of the auction also means that these would make a very special Christmas gift for any shark-lover.

The diversity of pieces mirrors that of the sharks and rays they represent. You can bid on paintings, digital creations, sculptures, mixed media and more. You can pick your favourite artist or species of shark. Or you can select the perfect artwork to make a statement in your home or office. Whichever you choose, you will be supporting the work to protect these amazing animals.

One of the pieces of art has been selected to be auctioned live by Steve Backshall at the For the Love of Sharks event at the Royal Geographical Society in London on the 29th November. In addition to this, two further pieces will be raffled at this event, giving people a chance to win an incredible piece of shark art. For the Love of Sharks is the Shark Trust’s flagship evening. A night to celebrate sharks. Steve Backshall is the headline speaker at this event that will see other prominent shark advocates join him on stage.

Tickets for the event can be snapped up here:

https://thesharktrust.org.uk/Event/flos24

Those that would like to see the Oceanic 31 exhibition have one final chance. It is being displayed at the Pavilion at the Royal Geographic Society from 26th November until the 7th December. Entry is free.

Find out more here:

https://www.rgs.org/events/upcoming-events/oceanic-31

 Paul Cox, Shark Trust CEO, Said “This exhibition has given us the opportunity to reach out to a new audience. And inspire more people with the wonderful sharks and rays on which our Big Shark Pledge campaign is based. We are immensely grateful to the 31 artists who have worked so hard to create these works.”

Bid for your favourite Oceanic 31 artwork here:
https://superstars-auctions.com/sharktrustauction


Banner Image: Smooth Hammerhead by Alicia Hayden

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Marine Life & Conservation

Meet Steve Backshall in the Bite-Back Prize Draw

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steve backshall

Until 28 November, prizes worth a massive £10,000 – including experiences, products and tuition – feature in a line-up of items that can be won for £5 in an online prize draw to celebrate Bite-Back Shark & Marine Conservation’s 20th anniversary and help generate crucial funds for the future.

Top of the list of prizes is the chance to spend time with adventurer and wildlife expert Steve Backshall, a workout session with Nat Geo star Aldo Kane, a kayaking trip alongside white-water expert and diver Sal Montgomery and a Zoom call with ‘shark whisperer’ Cristina Zenato.

On top of that, some of the most admired companies in the diving and scuba industry have been quick to support the charity with fabulous prizes that make the £5 ticket price worth more than just a flutter.

Master Liveaboards, BSAC, Midlands Diving Chamber, Go Freediving and Blue Shark Snorkel have all generously donated experience prizes, while celebrated photographer Alex Mustard has donated a print and artists Scott Gleed and Olivier Leger have donated a sculpture and illustration to help boost the fundraising pot.

Fourth Element has donated Ocean Positive gear and LA watch company Nodus has gifted the charity a stunning dive watch. For land lovers, the charity has included a five star London hotel stay at Bankside Hotel plus a family visit to Longleat Safari Park in the roster of prizes.

Campaign director for Bite-Back, Graham Buckingham, said: “We’ve been overwhelmed with support from companies and individuals that we truly admire and who have supported us on our 20 year journey and we’re truly grateful to them all. While we feel incredibly proud of our achievements over the past two decades – and we are super excited about the next chapter – this prize draw isn’t a vanity project. It represents a real lifeline to our work and important advancements in the global protection of sharks. So we hope divers, dive clubs and even bargain hunters grab some tickets to make this a massive success.”

The charity hopes that the prize draw will generate crucial funds to launch a brand new, ground-breaking, campaign to enrol the public and increase support for the protection of sharks around the world.

To enter the competition visit www.bite-back.com/prizedraw. The prize winners will be announced on 1 December 2024.

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