Gakka

Gakka is a seafood from the shores of Aparri. I am not sure if it's indigenous in the place, but I've never seen anything like it in other beaches all over the country.

It's a favorite snack food among locals, much like butong-pakwan, and is sold at sidewalks in season, usually during summer.

Gakka can be eaten by popping a piece into your mouth, holding it between your teeth, and cracking it on the middle, and then sucking its content.

Gakka is usually boiled before eating/selling, but I'm pretty sure it can also be eaten raw, just like many other shelled-food from the sea. (In Cagayan, it's not uncommon to see locals picking seashells from the water and then popping these into their mouth, and eating what's inside.)