The tawdry female bosses are tiresome, and we could do with more male fanservice.

[Roda]

Hmm. Honestly we might be overthinking fantasy anatomy. I think its a case of show not tell. Many languages aren't as gendered as english, and in many cases we don't have voices to rely on. We associate fertility and motherhood with body traits that Rukshs Dheem exhibits. Compounding themes with looks is a simple enough way to push them when you don't want to, or don't have time to develop them in more intricate ways.

Idk, out of place fish boobies don't really tell a good story? Especially since they are visually useless (no fish nipple or fish suggestion of fish nipple). A better way to display she was a brood mother would be to decorate her stage with fish brood props. Piles of fish eggs along the edges, carrying young in her fish mouth, that kind of thing.... 'cause she's a fish not a human, and I'm looking for fish tells of fish motherhood.

Ifrit and Bismark didn't really need such features, as they were strictly non-humanoid, and their gender never really mattered to the story or the themes / gods / beliefs they represented. Bismark for all intents and purposes could've been whatever gender and no one would notice. Same for Ifrit, but then he had a voice.

But that's the point. They don't have or need those features and yet we all still refer to them as males. It's really as simple as that. We're smart enough to not need to impose human body expectations on non-human monsters, and doing so kind of robs us of new and unique worldbuilding.