are the runts more sesceptible to health problems?

hey guys, i bought 5 peruensis scalares earlier in the year, one of them was alot smaller than the rest and now appears as if its swim bladder isnt working, was just wondering if, in your experience, its normal for the runts to have health problems possibly related to growth

otherwise i need to start thinking about other possible causes...

thanks, joel.

in my experience they are the first to get sick and the last to get better, that being said they can still live along time I've had runts last 7-8 years