Clams, proper, monstrous, giant clams.

I feel absolutely sure I've showed you something like this before but I'm damned if I can find it. It's the mantle of a Tridacna sp. clam (aka a giant clam). I'm not sure which (maybe small gigas maybe derasa?) but they are all similarly beautifully patterned.

Some of the smaller species (of the kind I thought I'd showed you) have a more electric blue or purpley mantle but they all do the same thing - feed the clam photosynthetically. Now the ones I thought I'd showed you would be clams that max out at 8-10 inches or so.

Now let's be clear - 8-10 inches is a giant amongst clams but it's not a giant clam. To show you giant clams I would have needed to a) go to the barrier reef, b) find a nice chunky Tridacna gigas and c) find a beautiful assistant to pose next to it to illustrate scale for you. Like this.....

 

Note how Becky, the dive buddy I randomly met on this boat trip, excellent diver that she handily turned out to be has stowed all her dangly equipment (gauges, octopus reg) very neatly away. If the old myths about how giant clams can suddenly close entrapping divers were true, she'd be perfectly safe as a result. They're not but both she and the reef are risk free as a result.