Hilsa fish, scientifically known as Tenualosa ilisha, is a popular and significant fish found mainly in Bangladesh, India, and surrounding regions. It is commonly referred to as "Ilish" in Bengali. Hilsa is an anadromous fish species, meaning it migrates from saltwater to freshwater to spawn. It is known for its distinct flavor and is highly valued in Bengali cuisine.

The Hilsa fish has a slender body and a shiny silver color, with a protruding lower jaw and a deeply forked tail. It is primarily a freshwater fish but can also be found in estuaries and coastal waters during its migration period. Hilsa is known for its rich, oily texture and is considered a delicacy in many South Asian countries.

One of the unique aspects of Hilsa fish is its cultural significance. In Bangladesh and West Bengal, India, it is not just a food item but also holds a special place in the cultural and traditional practices. It is often associated with festivals, celebrations, and special occasions, where it is served as a centerpiece dish. During the monsoon season, which coincides with the peak fishing season for Hilsa, various Hilsa festivals are organized to celebrate the abundance of this prized fish.

Hilsa fish is rich in omega-3 fatty acids, which are beneficial for heart health. It is a good source of protein, vitamins, and minerals, making it a nutritious addition to the diet. However, due to its high demand and overfishing, Hilsa populations have faced decline in recent years, leading to conservation efforts and regulations to protect this species.

In summary, Hilsa fish, or Ilish, is a culturally significant and highly prized fish in Bangladesh, India, and neighboring regions. Its unique flavor, cultural importance, and nutritional value make it a cherished delicacy in South Asian cuisine.