#cool creature

now for the neat examples i mentioned earlier or just think are cool that i didn’t want to interrupt the post with, plus images:

- digenean trematodes: they have the most complicated life cycle in the animal kingdom and have two or more hosts (parasite that causes one of, if not the highest, rate of parasitic deaths in the world). all of this group of worms (except for schistosomes) are hermaphroditic. i’ll save a lot of the really specific details for both my sanity and yours, especially since i just learned this in a parasitology lecture about an hour ago. but these worms have one genital pore used for both the cirrus (male external reproductive structure) and the metaterm (female reproductive structure accessed through this pore, basically a “vagina” of sorts). they have a crazy long convoluted uterus that at a quick glance is shaped like an intestine (but does not in any capacity act as one). the sperm has to travel all the way through this maze of a uterus to the mehlis’ gland, where the oocytes are fertilized and put in a protective coating. then those eggs travel all the way back up through it and are ejected from the metaterm through the genital pore. i’m not even gonna bother to get into the life cycle itself because dear lord. (image 1 shows a diagram of their bodies. the systems overlap. note that the caecum is their gut and not part of the reproductive systems and that not everything in the image is related to reproduction)

- Diplozoon paradoxum: this is a flatworm that is ectoparasitic to european cyrpinids (a type of freshwater fish). each diapora, or juvenile, cannot develop past that stage until they find another juvenile partner (or else they die). as the pair matures together, their genital ducts fuse permanently, having them in a state of perpetual copula for several years. as they are hermaphroditic, they are cross-fertilizing each other— both reproductive systems in each worm are functioning at once to both fertilize and be fertilized, producing constant offspring. (image 2 shows adults of these worms. the connection point between the two of them is where their genitals have fused)

- a non-parasitic example— temnocephalideans: these are adorable-looking ectocommensal (they live on the outside of their hosts and benefit from it, while having no negative effects on their hosts) flatworms that live on the shells of crustaceans in south and central america, oceania, and india. they feed on the food debris from the crustaceans (which are messy eaters) and have no effect on their hosts. they move sort of like an inchworm along the shell. i love these lil guys. (image 3 shows two of them. they have five little tentacles that they attach lightly to their host with basically little suction cups)

i really like worms and my parasitology class and professor but also the more i learn about what a hermaphrodite actually is the more frustrated i get that people use it to describe humans, especially as a slur. because not only is it completely offensive and uncalled for— it’s also just. not correct. that’s not what it means at all