# Ilish

The ilish (Tenualosa ilisha) (Bengali: ইলিশ, romanized: iliś), also known as the ilishi, hilsa, hilsa herring or hilsa shad, is a species of fish related to the herring, in the family Clupeidae. It is a very popular and sought-after food in the Bengal region, and is the national fish of Bangladesh and state fish of the Indian state of West Bengal.
As of 2023, 97% of the world's total ilish supply originates in Bangladesh. 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 under the Ministry of Industries declared ilish as a Geographical Indication of Bangladesh. 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.

## Common names

Other names include jatka, illi, ilish, ellis, palla fish, hilsha, ilih etc. (Assamese: ইলীহ/ইলীহি: ilih/ilihi, Bengali: ইলিশ, romanized: iliś, Gujarati: મોદાર/પાલ્વા: Modar or Palva, Odia: ଇଲିଶି, romanized: iliśi, Sindhī: پلو مڇي pallo machhi, Tamil: உள்ள மீன்/Ulla Meen, Telugu: పులస pulasa). The name ilish is also used in India's Assamese, Bengali, and Odia communities. In Iraq it is called sboor (صبور). In Malaysia and Indonesia, it is commonly known as terubok. Due to its distinguished features as being oily and tender, some Malays, especially in northern Johore, call it 'terubok umno' (to distinguish it from the toli - which species is rich in tiny bones and not so oily). In Myanmar, it is called (ငါးသလောက်) in Burmese which derives from the Mon language word ကသလံက် with က in Mon and ငါး in Burmese meaning fish.

## Description

Females of the species grow larger than males, with males individuals not reaching over 46 cm. Females can reach lengths of up to 55 cm. Maturity is generally attained by the end of the first year or the start of the second, with males maturing at sizes of 26–29 cm and females at 31–33 cm.
It has no dorsal spines but 18 – 21 dorsal soft rays and anal soft rays. The belly has 30 to 33 scutes. There is a distinct median notch in the upper jaw. Gill rakers fine and numerous, about 100 to 250 on the lower part of the arch and the fins are hyaline. The fish shows a dark blotch behind gill opening, followed by a series of small spots along the flank in juveniles. While alive, the fish is silver shot with gold and purple.

## Habitat and breeding

The fish is marine; freshwater; brackish; pelagic-neritic; anadromous; depth range of about 200 m. Within a tropical range; 34°N - 5°N, 42°E - 97°E in marine and freshwater. It is found in rivers and estuaries in Bangladesh, India, Pakistan, Myanmar (also known as Burma) and the Persian Gulf area where it can be found in the Tigris and Euphrates rivers in and around Iran and southern Iraq. 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 January to April). Actual peak breeding season of the fish is a topic of debate amongst the researchers.
After spawning, they return to the sea which are known as Jatka in Bangladesh (fish size up to 9 cm), although some stocks remain resident in rivers.
Since the 1900s, numerous efforts have been made to breed and cultivate hilsa across South Asia, especially in India and Bangladesh. However, no significant success has been achieved in completing the fish's life cycle in captivity.

### Feeding habit

The species filter feeds on plankton and forages in muddy bottoms. Its diet primarily consists of Bacillariophyceae (diatoms), Chlorophyceae (green algae), and crustaceans (Copepoda and Cladocera). While adults generally feed on Chlorophyceae and Bacillariophyceae, juveniles primarily depend on crustaceans.

## Production

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, followed by Myanmar and then India.
An estimated 97% of the total hilsa catch comes from Bangladesh. Ilish production in the country increased by 92% from 2008 to 2023.

## Food value

The fish is popular food amongst the people of South Asia and in the Middle East, but especially with Bengalis, Odias and Telugus of Coastal Andhra. Bengali fish curry is a popular dish made with mustard oil or seed. The Bengalis popularly call this dish Shorshe Ilish. It is very popular in Bengal (Bangladesh and India's West Bengal), as well as in Odisha, Tripura, Assam, Gujarat and Andhra Pradesh. It is also exported globally.
Ilish collected from Bangladesh is regarded the finest of all, celebrated for its size and subtle taste.
In North America (where ilish is not always readily available) other shad fish are sometimes used as an ilish substitute, especially in Bengali cuisine. This typically occurs near the East coast of North America, where fresh shad fish, which tastes similar to ilish, can be found.
In Bangladesh, fish are caught in the Meghna-Jamuna delta, which flows into the Bay of Bengal and Meghna (lower Brahmaputra), and Jamuna rivers.
In India, Rupnarayan (which has the Kolaghater hilsa), Hooghly, Mahanadi, Narmada and Godavari rivers and the Chilika Lake are famous for their fish yields.
In the Indian state of Andhra Pradesh, hilsa takes on a special significance. Here, the term "pulasa" refers specifically to the larger, mature hilsa that migrate upstream along the Godavari River. This migratory journey is crucial, as it's believed that the Godavari's unique muddy waters contribute to the development of a richer flavour and firmer texture in the fish, compared to hilsa caught elsewhere. Due to this perceived superior quality and its limited seasonal availability (typically monsoon season), pulasa commands a significantly higher price and cultural importance in Andhra Pradesh. It is considered a rich delicacy, often referred to as the "king of fish" in Godavari Areas and features in celebratory meals and as a prized gift. The upstream migration itself is seen as a vital natural process, and the pulasa a reward for the patient fishermen who wait for its arrival.
In Pakistan, most hilsa fish are caught in the Indus River Delta in Sindh. They are also caught in the sea, but some consider the marine stage of the fish as not so tasty. The fish has very sharp and tough bones, making it problematic to eat for some.
Ilish is an oily fish rich in omega 3 fatty acids. Recent experiments have shown its beneficial effects in decreasing cholesterol level in rats and insulin level.
In Bengal and Odisha, ilish can be smoked, fried, steamed or baked in young plantain leaves, prepared with mustard seed paste, curd, aubergine, different condiments like jira (cumin) and so on. It is said that people can cook ilish in more than 50 ways. Ilish roe is also popular as a side dish. Ilish can be cooked in very little oil since the fish itself is very oily.

## Ilish in culture

* Ilish is the national fish of Bangladesh.
* In Andhra Pradesh, the saying goes "Pustelu ammi ayina Pulasa tinocchu", meaning roughly "It's worth eating Pulasa/Ilish even if you have to sell your mangala sutra. Hilsa is also known as pulasa in Godavari districts of the state. The name Pulasa stays with the fish for a limited period between July–Sept of a year, when floods raise the Godavari River. This time the fish is in high demand and sometimes $100 per kilo.
* In many Bengali Hindu families a pair of ilish fishes (Bengali: Jora Ilish) are bought on auspicious days, for example for special prayers or puja days like for the Hindu Goddess of music, art and knowledge Saraswati Puja, which takes place in the beginning of spring or on the day of Lakshmi Puja (the Goddess of Wealth and Prosperity) which takes place in autumn. Some people offer the fish to the goddess Lakshmi, without which the Puja is sometimes thought to be incomplete. It is often given as gifts (Bengali: tattwa) in Bengali weddings.
* Hilsa is also known in Sindh as Pallo Machi and is important part of Sindhi cuisine, prepared with numerous cooking methods. It can be deep fried and garnished with local spices, can be cooked with onions and potatoes into a traditional fish meal or barbequed. The fish often has roe, which is called "aani" in Sindhi and is enjoyed as a delicacy. Often fried alongside the palla and served with the fish fillets.
* The rivalry of East Bengal and Mohon Bagan, two football clubs of Kolkata are celebrated by food. When East Bengal wins, an ilish (hilsha) dish is cooked by the East Bengal supporters. Similarly, when Mohon Bagan wins, a Chingri (Prawn) dish is prepared by the Mohon Bagan supporters. These items often occur in the tifos of these respective clubs.

## Overfishing

Due to the demand and popularity of this species, overfishing is rampant. Fishes weighing around 2 to 3 kilograms have become rare in India, as even the smaller fish are caught using finer fishing nets as production in Bangladesh have increased. As a consequence of this, prices of the fish have risen. In the past ilish were not harvested between Vijaya Dashami and Saraswati Puja due to some informal customs of Odia and Bengali Hindus as it is the breeding period of the fish. But as disposable incomes grew, wealthier consumers abandoned the old traditions.
The advent of finer fishing nets and advanced trawling techniques, and environmental degradation of the rivers, has worsened the situation. Fishermen have been ignoring calls to at least leave the juvenile "jatka" alone to repopulate the species. The fishing of the young jatka is now illegal in Bangladesh. This ban however has resulted in a rise in unemployment, as around 83,000 fishermen are unable to pursue their former livelihood for eight months every year. It has also led to the creation of a black market where jatka are sold for exorbitant prices. Furthermore, the changes brought about by global warming have led to a gradual depletion of the ilish's breeding grounds, reducing populations of the fish even further. Pollution in rivers have worsened the situation, but due to slightly better waters the fishes are found more near Bangladesh delta. Owing to this situation ilish is used as a diplomatic trade item, most recently in the distribution of COVID-19 vaccines.
Bangladesh has regularly imposed restrictions on the export of ilish abroad, citing its scarcity. Despite this, former Prime Minister Sheikh Hasina periodically lifted the ban to allow the annual export and gifted of 3,000-5,000 tonnes of fish to India during the Durga Puja, popularly known as "Hilsa Diplomacy". Since the fall of the Hasina government, the interim government of Bangladesh has imposed a ban on ilish exports, which was partially lifted on 21 September 2024 to allow for the export of 3,000 tonnes of fish for Durga Puja.