Flame Scallop

Image: Tony Shih
Lima scabra

The sea, the sea, the sea is on fire!
We don't need no water 'cos... where would we put it?

It's the Flame Scallop! Electric Scallop! Flashing Scallop! Disco Scallop! And guess what it isn't... that's right, a scallop! It's a File Clam instead, which looks superficially similar but actually belongs to an entirely different order.

Video: coralpublications

As you can see, some of them are extremely colourful, or at least red-full. Also tentacle-full. I'd love to imagine them parading around, strutting their stuff, tentacles a-flutter like terrifically excessive eyelashes. Alas, File Clams prefer to retire into the cracks and crevices of the seabed to be safe from predators. They only reach 7.5 cm (3 in) long so they're good at hiding away.

They can't keep their shell shut with the kind of strength many of their relatives can, so when a devilish starfish comes along they make their escape by kind of swimming. They flap their valves and propel themselves away. I guess if you can't strut your stuff when you're running away from certain death, when can you?

But what about the Electric Flashing Disco?

Video: liquidguru

Who's been eating plasma balls? Flame Scallops look as if they have sparks of electricity playing around their mantle. Those eyelashes went from the sublime to the ridiculous! And onward to the completely mad.

As it turns out, these flashes are neither electricity nor bioluminescence. Rather its a strip of (super-duper) reflective tissue which can be covered and uncovered to produce the effect. No-one knows why they do it! It could be for luring the tiny prey they feed on, or maybe luring larvae of their own species so that they'll settle nearby. These clams start out male and become female as they grow bigger and since they can''t move much, it's a good idea to have lots of their own kind close at hand/tentacle/eyelash.

One cool fact is that Lima scabra comes from the Caribbean while in the Indo-Pacific is another, extremely similar species called Ctenoides ales. It's totally appropriate for that kind of style to think global. I can't wait for the world tour of the Electric Flashing Disco!