#mollusks

we're all familiar with the feeling of dreading the incoming winter for 9 months a year and there's no lack of reasons why, but i think the most understated one is that truly it is the worst time for having to watch your step - hazards include mud, puddles, and of course, slugs. even a single individual is obviously not something i want to accidentally harm so it would've been extra catastrophic if i hadn't noticed this very busy Arion couple in time

I love Nautiluses (⁠´⁠ε⁠｀⁠ ⁠)They are too cute

Southern Spiny Chiton - Nuttallina fluxa

while both of these snails may be big fans of cymbals, each one of them has a very specific and restrictive description of what they think should count as one, and they both can't stand listening to music that doesn't include their preferred idea of a cymbal

because of this they get into long arguments about the concept of cymbals and what counts as good music on an almost daily basis

glorpiness rating: woohhh 🫧 (pummg)

photographed by D. Torres-Pulliza (dama) (CC BY-NC 4.0)

Ok, so the way snail sex works is madness-inducing. When gastropods moved on land, they became hermaphroditic so it was easier to find compatible mates, since they move so slow and you can't broadcast gametes outside of water, which is sensible enough.

But here's how it works. The ovotestis, embedded in the hepatopancreas, is simultaneously an egg-producing ovary and a sperm-producing testicle. Newly produced eggs travel to the spermatheca to await fertilization. Sperm also goes to the spermatheca, travels further along the vas deferens which is embedded in the oviduct but separated from it, into the epiphallus. Here it is mixed with the protein coating secreted by the flagellum, forming the spermatophore. The fully coated spermatophore goes into the penis, which turns inside-out like a glove finger during copula to go into the partner.

At the same time, the partner's spermatophore is received into the vagina, travels along a narrow duct toward the bursa copulatrix where the spermatophore coating is digested, and then the released sperm travels back along the same duct to go into the oviduct and then the spermatheca, where it can fertilize the eggs. At that point the fertilized eggs are coated in albumen by the relevant gland and go down the oviduct and the vagina to be laid out.

Oh, and there's also the "love dart", a lubricated calcareous spike that stabs the partner during mating, not to transfer gametes but hormones that make it more receptive to the spermatophore.