Niboshi

Niboshi , often called iriko (炒り子) in Western Japan, are small dried fish used in Japanese cuisine for making dashi (soup stock). They can also be eaten as snacks, or as a side dish. The types of fish used include anchovies, sardines, round herring, Pacific sand lance [ja] and others. Niboshi made of anchovies are the most common. The word niboshi (煮干し) literally means "boiled" or "dried", and it does not include the specific name of the ingredient. For this reason, niboshi is translated both as "dried sardine" and "dried anchovy". The translation of the term niboshi is an object of confusion among Japanese speakers, in terms of whether it is sardines or anchovies, because in Japanese, both sardine and anchovy are referred to as iwashi (イワシ).

Source: Wikipedia