What pragmatic factor dictates the physical handling difference between swordfish skin and that of a snapper?

Answer

The swordfish skin is extremely tough, and improperly removed skin exposes abrasive, embedded scale spines near the flesh

The skin itself is very tough, and if the slime coat is gone or the dermal layer is damaged during processing, the small, buried scale spines can create an unexpectedly abrasive texture.

What pragmatic factor dictates the physical handling difference between swordfish skin and that of a snapper?
skinfishanatomyScaleswordfish