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


Sea Biscuit Close-up, Abaco (Keith Salvesen)

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.

Sea Biscuit 'Doves', Abaco (Keith Salvesen)

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…

Sea Biscuit 'Doves', Abaco (Melissa Ann Guinness)

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

Sea Biscuit 'Doves', Abaco (Melissa Ann Guinness) Sea Biscuit 'Doves', Abaco (Melissa Ann Guinness) Sea Biscuit 'Doves', Abaco (Melissa Ann Guinness)

The final reconstruction – 5 doves and a bonus brittle star

Sea Biscuit 'Doves', Abaco (Keith Salvesen)

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

3 thoughts on “SEA BISCUITS: THEY REALLY DO CONTAIN DOVES – AND MORE!

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