What about bees? I didn't know they had any sex changing or multiple different sexes, only that the males only existed for mating with the queen and then die
TL;DR: All fertilized eggs become female bees. Whether a fertilized egg becomes a worker or a queen is based completely on how much royal jelly they are fed by other workers as larvae. Drones (male bees) are born from unfertilized eggs and only contain one set of chromosomes.
Also, there are reptiles that change sex based on the temperature in which their eggs develop. Sex gets weird in the animal kingdom.
I'm absolutely a trans ally but what I don't understand about how science defines the sexes without reproduction. If those mushrooms have thousands of sexes, must they participate in gigantic fungal orgies every time they reproduce? Of course given that fungi are in an entirely different kingdom than mammals, I wouldn't be surprised if how sexes are defined is entirely different and irrelevant to how they're defined in animals.
My biology education ended at high school and unfortunately it was a high school that taught that the earth was 6000 years old so to say it was lacking would be an understatement.
Basically for these fungi, only different "sexes" can reproduce with each other. Still only need two for reproduction. They can't reproduce with the same sex. So A can mate with B, C, D, etc. A can't mate with A. Do dna sequencing on a few that you know can mate with one another and you can find where the sex allele/gene is. Then you can sequence the population at large to see how many different sex alleles there are. You can confirm or do old school observation to see which ones can reproduce with another.