Last Updated On 23.06.2016

  1. Hilsa catch structure, population parameters, growth, age at length, Maximum Sustainable Yield (MSY), Spawning Stock Biomass (SSB), Maximum Economic Yield (MEY); feeding habits, reproductive characters, sex ratio and size at first maturity in Hooghly estuary have been established.
  2. Major habitat parameters influencing hilsa (Na, K, Cl, Ca, Mg, Sp. conductivity, Salinity, T. hardness, Temperature) with favorable ranges in nature have been worked out.
  3. Established distinct genetic divergence in hilsa of Hooghly from that of Brahmaputra and Padma and existence of four distinct genetic stocks in the marine sector viz 1. (Digha, Kirtunia, Dhuleshwaram, Yanam,Kakinada) 2. Chudamani, 3. Badrak, 4. Vella estuary established.
  4. Role of plasma estradiol and 17a 20ß-dihydroxy progesterone (DHP) in growth and maturation of oocytes and that of 11-keto-testosterone in spermatogenesis elucidated.
  5. Protocol for artificial breeding of natural brooders standardized.
  6. After artificial breeding, 42.5% larval survival, 30% nursery stage survival and 20% survival in grow out stage in ponds has been achieved. Currently standardization for better survival and growth are progressing.
  7. Milt cryopreservation trials resulted in generating viable sperms up to eight months of cryo-storage
  8. Under brood stock development trials, ovary maturation up to stage 4 achieved; trials are on for further maturation in pond conditions.
  9. Males reached milting stage with viable sperms in pond condition.
  10. Natural live food organisms identified, isolated and mass culture developed for feeding early larval stages.
  11. An artificial feed with 30% protein developed and is under trial for digestibility and nutrient requirement.
  12. Hilsa fry and fingerlings have been weaned to accept artificial feed in pond condition.
  13. Hilsa seeds (81.11 ± 1.88 mm/ 5.4 ± 0.4 g) stocked in freshwater ponds grew to 259 mm / 160 g in 19 months with 20% survival; while in brackish water ponds, hilsa seeds (52.97±5.50 mm/1.37±0.18 g) grew to 360g/ 330mm size in 21 months with 30% survival.
  14. Habitat specific chemo attraction in the fish has been established.