Sea Biscuit Abaco | ROLLING HARBOUR ABACO

SEA BISCUITS: THEY REALLY DO CONTAIN DOVES – AND MORE!

Recently I posed the question whether sea biscuits, like sand dollars contain ‘doves’. I had one in my hand, it rattled, I took a photograph through its ‘mouth hole’ and the question was answered. Biscuits do indeed contain doves – see HERE for details and comparisons with dollar doves.

However, I spinelessly* failed to break open the biscuit to check out the contents more closely. I theorised that, because of the 5-way symmetry of these creatures, there would be 5 doves (which are in fact segmented mouth parts) in a biscuit exactly as with a dollar, and amiably challenged anyone to disprove it. [* biscuits and dollars are types of sea urchin – see what I did there?]

Dollar dove in close-up – one of 5 segmented mouth parts inside the ‘test’ (skeleton) Sand Dollar 'Doves', Abaco (Keith Salvesen)

Melissa Ann Guinness from Hope Town has a far more robust attitude to these things and, taking up the challenge, she heartlessly smashed open a sea biscuit from her collection to investigate further. I said I’d publish a correction if my theory was wrong. This is it – though in one arguable sense the theory holds good. It just didn’t go far enough…

In the above picture you can see (a) 4 quarters of a sea biscuit skeleton (b) 10 demi-doves (rather than 5 whole doves) and (c) a small mummified 5-limbed brittle star that was presumably in the creature’s digestive system when it died.

10 ‘demi-doves’ (or, when assembled, 5 doves that (unlike sand dollars) are in 2 parts
Sea Biscuit 'Doves', Abaco (Melissa Ann Guinness)

Complete doves

The final reconstruction – 5 doves and a bonus brittle star

Photo Credits: Keith Salvesen (1, 2, 3, 10); Melissa Ann Guinness (4, 5, 6, ,7 ,8 ,9)

Sea Biscuits, Delphi, Abaco (Clare Latimer)

Sea Biscuits on the Beach, Delphi, Abaco Bahamas

SEA BISCUITS: DO THEY REALLY CONTAIN DOVES?

A couple of years ago I wrote a post called ECHINODERMS, DOLLAR DOVES & PETRIFIED BISCUITS. It dealt with the… fact? rumour? old wive’s tale?… that within each sand dollar test (i.e. the white skeleton) are hidden 5 ‘doves’. You can hear them rattling inside if you shake the dollar…

Sand Dollar from Abaco containing 5 miniature white doves…

I investigated the theory with senior granddaughter, and we broke a sand dollar in half. And as you can see, the answer was undoubtedly yes – there were 5 tiny white doves, thus fulfilling the prediction of the famous ‘Sand Dollar’ poem that contains the lines “Now break the centre open And here you will release The five white doves awaiting To spread good will and peace”.

Five white doves (in fact, the separated parts of the creature’s feeding apparatus) Sand Dollar Doves (Keith Salvesen) 1

A single dove, a picture of doveliness Sand Dollar Doves (Keith Salvesen) 3

I never thought to extend the experiment to sea biscuits, another object prized by beachcombers. All that changed last month when I picked up a sea biscuit and found that it, too, rattled.

A rattling good sea biscuit

So I turned it over to take a closer look at the underside. And there, unmistakably, was the source of the rattle – some kind of internal arrangement inside the feeding hole (let us not pause overlong to consider the purpose of the other hole). But it wasn’t conclusively a dove.

So I shook it around a bit (sorry, doves) and zoomed in. And there was a small white columbine-type contraption remarkably similar to those found in the dollar dove. And no, I did not smash open the sea biscuit (it wasn’t actually mine). And no, I didn’t doubt any longer that sea biscuits also contain doves.

SO WILL THERE BE 5 DOVES, LIKE WITH THE DOLLARS?

I predict there will also be five. Both dollars and biscuits have ‘five-way symmetry’ (look on the topside of a biscuit or dollar to see how); and so the mouth (from which the ‘doves’ derive) will have a single part for each of the five sectors, all linked.

If anyone would like to smash up one of their precious beach finds and test the theory, please feel free. Prove me wrong… and I’ll publish a correction! [Photo please…]