Bangladesh's national fish that runs up monsoon rivers
Tenualosa ilisha—ilish, hilsa, or hilsa shad—is a herring-family migrant prized across Bengal and named Bangladesh's national fish as well as West Bengal's state fish. As of 2023 the sources credit Bangladesh with about ninety-seven percent of world supply, roughly twelve percent of that country's fish catch and a bit over one percent of GDP.
Females outgrow males: males stay under about forty-six centimetres while females may reach fifty-five. Maturity comes near the first year's end, males around twenty-six to twenty-nine centimetres, females thirty-one to thirty-three. Live fish shine silver shot with gold and purple; juveniles show a dark blotch behind the gill opening and a row of flank spots. They filter-feed plankton—adults mainly diatoms and green algae, juveniles more crustaceans—and use muddy bottoms.
Ilish are anadromous, schooling in coastal seas then pushing roughly fifty to one hundred kilometres up rivers to spawn in southwest-monsoon windows (sources cite June–September and January–April; peak timing is debated). They range across eleven countries from the Bay of Bengal to the Persian Gulf's Tigris–Euphrates; Bangladesh leads production, then Myanmar and India. Young returning fish under about nine centimetres are called jatka in Bangladesh. Captive full life cycles have been tried since the 1900s without major success.
Cuisine treats the oily flesh as a regional icon—mustard-based Shorshe Ilish in Bengal, dozens of smoked, fried, or leaf-wrapped preparations—and Andhra's monsoon "pulasa" from the Godavari commands premium prices. About 450,000 people catch it directly and millions more work the trade; Bangladesh production rose sharply under breeding-season bans that also idle tens of thousands of fishers. Overfishing and river degradation have made two-to-three-kilogram fish scarce in India even as Bangladesh output climbed.
Source: Ilish
