Buuuuuut mursaat are fleshy, solid creatures, or at least look like it. These guys are glowy. Margonites are glowy too and they were humans that were corrupted by Abaddon. Maybe these mursaat were transformed in a similar way.
Or it could be that this was their true form all along and they just looked fleshy in GW1 because reasons.
The glowing parts could be armor, like our zodiac armor.