mollusk of the week!

i'm squeezing this one in a little late! i've had a busy week, but what better way to unwind than to learn about a beautiful new mollusk? this week's bivalve is a show-stopper, the largest of their kind...

this week's mollusk is: tridacna gigas, the giant clam!

clams! they seem simple, but they're fascinating creatures, and these guys certainly stand out from the crowd. with their beautiful, vibrant mantles and extravagant shells, they are highly sought after both as a delicacy and an ornament, which has unfortunately led to their endangerment :[ thankfully there are conservation efforts in place, and international trade is regulated. hopefully one day they can be restored to their former glory!

giant clams, as suggested by their name, are the largest living bivalve mollusks! the largest one ever recorded was a staggering 137 cm (4ft, 6in) and weighed 510 lbs! if i laid down next to it, it'd take up like 90% of my body in length! 

like last week's mollusk, these peaceful creatures are filter feeders, deriving 65-70% of their nutrition from zooxanthellae, single-celled, endosymbiotic eukaryotes which are considered protists - meaning they are neither animal, plant, nor fungi! i went down a massive rabbit hole looking into these guys, it's a pretty interesting subject that i highly recommend looking into! but i can't let them steal the show from their hosts... 

now, their beautiful colors are thanks to both the clam's natural pigment and the cultivation of algae inside their body tissue (which contributes to its rapid growth rate). due to its significant size, a lot of people misunderstand them as dangerous, but in reality, their abductor muscle contraction is too slow to trap a human or cause any significant injury. they are also sessile after the larvae stage, meaning that like coral, they are fixed in place and do not move in adult life. truly the most neutral good of creatures! they happen to reproduce sexually, and are hermaphrodites, producing both egg and sperm and releasing them into the open water in what is referred to as broadcast spawning.

another particularly awesome aspect of the giant clam is their eyes, of which they can have several hundred to several thousand! because sunlight is extremely important to their survival, given the photosynthesizing algae from which they receive feeding, they have photoreceptors sensitive to three different ranges of light, including ultraviolet. this means they can open and close their shells in response to changes in the light around them, or nearby movement. 

in this picture, you can see the eyespots on the mantle! here's a little gallery of giant clam pictures as always :]

i struggled to decide what to include in this blogpost because these are truly complex creatures. i hope i can inspire some of you to look into them further because there is much more information to discover! please forgive any mistakes in this one -.- i am very sleep deprived at the moment. thanks for reading!

hint for next week's mollusk: referred to as chameleons of the sea, these intelligent, color changing cephalopods first appeared in the miocene epoch.