Escarglow
I couldn't decide, so I just said them out loud, and Escar.glow sounds so much better than Mol.lux said out loud. Seriously, try saying Mol.lux out loud. You can't say it without taking away from either the Mollusk or Lux part. It either sounds like you're mispronouncing Mollusk or like Bollox with an M. Escar.glow doesn't have that problem, neither part of the name verbally detracting from the other. Similarity to Magcargo be damned, Escar.glow has my vote.