What type of relationship exists between the bluestriped fangblenny and the lizardfish?

Negative/Competitive

Explanation:

The Lizardfish has a positive relationship with the Blue Streak Wrasse, the Blue Streak Wrasse eats parasites that are potentially deadly to the Lizardfish. The Bluestriped Fangblenny imitates the Blue Streak Wrasse, giving the Lizardfish a false sense of security, but instead of eating off parasites, the Bluestriped Fangblenny eats off the Lizardfish's skin!