Hilsa fish migration 🐟

~Hilsa fish migration 🐟~

• Catadromous migration of fresh water fishes to sea for egg-laying (spawning).

• Examples : European eel (Anguilla rostrata) and American eel (Anguilla vulgaris).

~Eel (Anguilla) fishes live in fresh water rivers. During breeding season ~

• Their colour changes from yellow to silver;

• Their digestive system shrinks;

• Feeding is stropped;

• Eyes become large;

• Snout become more sharper;

• Gonads become mature full and

• Reproductively mature. Silver eel desend the river and enter into the sea.

• It migrates about 4500 Km from Europe / America to Sargasso sea off Bermuda (breeding ground / spawning place).

• Silver eel, then, lays the eggs in the deep water and die immediately after.

Hilsa fish migration 🐟

• The eggs hatch into larvae. Each larva is small. transparent, leaf-like, flattened and swim in the sea water.

• Larvae start their journey to home place along with sea waves.

• The larvae grow into glass eels.

• On reaching in land, the female ascend in the river water.

Hilsa fish migration 🐟

• They feed and grow into yellow eels. The males remain behind in the brackish water. Here, fresh water (eels) migrates to

Hilsa fish migration 🐟