The ilish is a species of fish related to the herring, in the family Clupeidae. Hilsa is one of the most tastiest fish due to its distinctly soft oily texture, mouthwatering flavor and superb mouthfeel. It is a very popular and sought-after food fish in the Indian Subcontinent. The fish is locally called “Macher Raja” means the king of fish. It is the national fish of Bangladesh and state symbol in the Indian states of West Bengal and Tripura. The fish is marine; freshwater; brackish; pelagic-neritic; anadromous; depth range – 200 m. The fish schools in coastal waters and ascends up the rivers (anadromous) for around 50 – 100 km to spawn during the southwest monsoons (June to September) and also in January to April. April is the most fertile month for the breeding of ilish. The young fish returning to the sea are known in Bangladesh as jatka, which includes any ilish fish up to 9 inches long. The fish is found in 11 countries: Bangladesh, India, Myanmar, Pakistan, Iran, Iraq, Kuwait, Bahrain, Indonesia, Malaysia and Thailand. Bangladesh is the top hilsa-producing country in the world. The fish contributes about 12% of the total fish production and about 1.15% of GDP in Bangladesh. On 6 August 2017, Department of Patents, Designs and Trademarks (DPDT) under the Ministry of Industries of Bangladesh has declared the recognition of ilish as the product of Bangladesh. 70-75 percent of total produced ilish in the world is produced in Bangladesh which applied for Geographical Indication (GI) in 2004. About 450,000 people are directly involved in the catching of the fish as a large part of their livelihood; around four to five million people are indirectly involved with the trade. The fish is popular food amongst the people of South Asia and in the Middle East, but especially with Bengalis and Odias. Bengali fish curry is a popular dish made with mustard oil or seed. The Bengalis popularly call this dish Shorshe Ilish. It is also popular in India, especially in West Bengal, Odisha, Tripura, Assam, Gujarat and Andhra Pradesh. It is also exported globally.
In Bangladesh, fish are caught in the Meghna-Jamuna delta, which flows into the Bay of Bengal and Meghna (lower Brahmaputra), and Jamuna rivers.