crooked

The other day i enquired about some bogwood, seller said he was shutting down tank so the 6 fish he had ( 3 zebra danio's and 3 panda cory's ) would have to go with it. I thought their water requirements and temp matched those of my tank so i didn't decline. My tank is 160 ish litres and...

My fiance recently added some scissortail rasboras to our tank, I wasn't too interested in them but we got them anyway, and despite my pleading to not get the gimpy one, again he got it anyway.  So my question is...what's wrong with it? is it just a physical defect or is it diseased or...