Dendrogaster (a crustacean that parasitizes starfish)
this is how they look
WHAT DO YOU MEAN, CRUSTACEAN.
my tags need to go in the main part of the post actually
There's a different species of barnacle, Sacculina, that parasitizes crabs in a similar way to this. It has a very cursed lifecycle and I assume the crab is also having a weird time.
I think i've heard of this one.
I just looked it up—it injects itself into the crab's body and replaces the crab's genitals with itself, grows roots into the crab's organs (including its brain), and controls the crab's behaviors so the crab will take care of the Sacculina larvae as a female crab would its own babies—if the crab is male, the Sacculina parasite will make the crab's body produce female hormones to basically change it to female.
This is so cool...how did this even develop? How did the parasite evolve to do that? How ancient would this relationship have to be for something so complex to form?



















