Polefishing: Amduskia Coral - help?

So I've been trying to complete this quest for days by farming in the volcanic caves, however Amduskia Coral has not dropped once yet and I'm wondering whether it's just super rare or if I'm doing something wrong?

Thank u for any help!!

Fishing can be a fickle mistress. Amduskia Coral is a rare item, and is "Medium-sized" and "Unique," so any Cuisine that boosts either of those will help you chances of getting one.

Also, it would probably be a good idea to have some Fishing Stamina Drinks on hand so that you can take advantage of the boosted rates during a Fever.