I know what you mean about thinking of icthy as being a mermaid. I like to think of my daughter in that light (she died 3days with harlequin icth) I don't believe she was a mistake. i believe she is
something better than normal people. She was us evolving, growing a protective armor. I think if all the problems (limited movement, dehydration, etc.) could be cleared up, maybe it would be benefitial to have skin such as hers. Insects and some animals benefit from thinkened skin. Maybe it would protect from radiation (sunburn and nuclear). Have you seen Hellboy or read the comics? I think of her akin to Abe Sapien. They even make mention of "icthy" in the movie. If we could have just made her a little tank for her to swim in, her skin would not have broken and she might be here. I mean we all breathe water for 9 mths (remember the Abyss). Don't think that I am crazy, these are just some ideas that I have been coming up with since I think about it all the time. Here is a rough draft of a poem that I wrote about her.

I want to hold you close
but your skin keeps us apart
I never imagined it could cause you pain
that which holds others together
keeps us away
your skin binds you in
Oh Anima,
to break your chains
I'd cut them with my very life
but I can't touch them
the links fall from my grasp
and you felt pain
and I feel pain now