Why are delhezi's called armored bichirs?

[The Keeper]

Why are they called armored bichirs do they have tougher scales or something?

 

[jaws7777]

I think its the gray color.... maybe

 

[Polyaddict86]

Just to make it sound tougher, lolz

 

[DMD123]

I think its due to the way its designed.

Interesting read for ya, http://www.popularmechanics.com/science/a12086/4275401/

Article mentions sens but I think the scale composition is pretty much the same in all the polys.