Sardine

The oil is only in the description. The game calls the sardine a small oily fish, and you might expect that oil to go somewhere, but no recipe takes a sardine. It does not turn into fat or fuel. It turns into dinner.

Its text also says sardines are commonly found in large schools, and that fits how they show up. You sit on a pier with a handmade fishing rod, one bites, and the next few casts bring more of the same. Ten fit in a slot. Gut them with a knife between bites and each gives a little raw fish, which stacks far better than whole fish.

The anchovy is close to a twin: small, schooling, eaten the same way. Cook either into cooked fish and do not plan a trip around them.