Yep, the monthly themed calls issue is out and that's an actual quote from one of the markets, called (surprise!) Crab Tales. Given that the crab form has actually evolved multiple times in the history of the Earth (not all modern "crabs" are actually "crabs" in strict taxonomic sense, just in appearance), could be a fun one to write.
Other themes on offer? Bears in the big hairy gay male sense, cats, the future of rodents (called Rattus Futura), tarot cards, and so much more. Heavy on spec fic (fantasy, s-f, horror) as usual but there's some other stuff, too.
https://authorspublish.com/47-themed-submission-calls-for-september-2023/