Does the Primal bloodline sorcerer apply his arcana to his elemental ray SLA? This would add +1 damage to the ability making it slightly more viable at lower levels.
The arcana states that it applies "Whenever you cast a spell". SLAs generally function like spells, but aren't exactly spells.
Yep, SLAs are not spells and therefore the arcana doesn't work. I am all in favor of upping the pretty useless low level caster abilities, though, since they need it (most are on par with a light crossbow, which you can fire all day long).