i'm hyperfixating on cuttlefish rn so here's some fun facts abt their anatomy :} cuttlefish possess an internal structure called the cuttlebone! it is porous and made of aragonite, which is a naturally occurring crystal form of calcium carbonate. the pores provide cuttlefish with buoyancy. each species' cuttlebone has a distinct shape, size, and pattern of ridges or other texture. the cuttlebone is unique to cuttlefish, and it's one of the key traits that differentiate them from squids! also! cuttlefish have smoothly curving w-shaped pupils, and they can't see colour! but, they can see the polarization of light, so they have an enhanced perception of contrast! they also use stereopsis, or binocular vision, to discern depth/distance as their brain calculates the input from both eyes!! many different cuttlefish are also venomous! or poisonous like the flamboyant cuttlefish :} sorry for infodumping in your retrospring i think these creatures are really silly ok bye bye <3