Roach

Roaches (Särki in Finnish) are one of the most common fish, along with perches. They weigh less than 1 lbs, and even if 'delicious' when cooked, will only fill a sliver of your hunger bar. While large quantities of roaches (in the vein of 10 - 20 roaches) can fill your hunger bar, it is far more efficient to just keep fishing until you catch a larger fish, such as a pike.

Roaches are rarely used for anything other than bait due to their small nutrition value and low weight. They are also useful as sacrifices to appease the spirits.

Wikipedia article about Roach (English)

Wikipedia article about Roach (Finnish)