Fish are members of poikilothermic (cold-blooded) vertebrates[1] that live in water and breathe through gills. Fish are the most diverse group of vertebrates with more than 27,000 species worldwide. Taxonomically, fish belong to a paraphyletic group whose kinship relationship is still debated; fish are usually divided into jawless fish (class Agnatha, 75 species including lampreys and hags), cartilaginous fish (class Chondrichthyes, 800 species including sharks and rays), and the rest are classified as bony fish (class Osteichthyes). Fish in various regional languages ​​are called iwak (jv, bjn), jukut (vkt).[2]

Fish come in a variety of sizes, from whale sharks measuring 14 meters (45 ft) to stout infantfish measuring only 7 mm (approximately 1/4 inch). There are some aquatic animals that are often considered "fish", such as whales, squid and mermaids, which are not actually classified as fish.

Until now, fish are generally consumed directly. Processing efforts have not been done much except for salted fish. Fish can be processed into various products such as dried fish, fish jerky, shredded fish, fish crackers, salted fish, kemplang, fish balls and fish blood meal as plant fertilizer and fish feed.