Jesus fuck. I knew about these guys but did not know they perform this by hanging out in fish gills until they get a breeding pair, them one crawls from the gil

Jesus fuck. I knew about these guys but did not know they perform this by hanging out in fish gills until they get a breeding pair, them one crawls from the gills to the tongue to clamp on and replace the damned thing, and later they reproduce and spread young from the gills!