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  • 1. Irrawaddy DOLPHINS
    Presentation by
    Dr MadhusudanSubudhi
  • 3. Taxonomy
    Kingdom _ Animalia
    Phylum _ Chordata
    Class _ Mammalia
    Order _ Cetacea
    Family _ Platanistidae
    Genus _ Orcaella
    Species _ OrcaellaBrevirostris
  • 4. Physical description
    Slaty blue to slaty grey
    Under parts are slightly paler
    180 to275 cms
    Body weight
    May go up to 190 kg(418 lbs)
  • 5. Gross Anatomy
  • 6. Gross anatomy
    Bulging fore head
    A very short beak
    Pectoral fin is broadly triangular
    Small dorsal fin towards posterior end of the back
    U shaped blowhole opens to the front(unlike other sps)
    12 to 19 teeth on each side of each jaw. Narrow pointed peg like teeth about 1cm length
  • 7. Gross Anatomy (contd)
    Two unique anatomical features of this sps:
    Stomach is divided into two into two compartments
    Muscular part & glandular part
    Cardiac sphincter is absent
  • 8. Male reproductive organ of dead Irrawadidolphinedesected by Dr M.subudhi & MrMumtajalli khan.
  • 9. Grossly healthy kidneys of a dead Irrawady dolphin dissected by Dr M.Subudhi & Mr.Mumtazalli Khan
  • 10. Physical behavior
    They prefer coastal, brackish & fresh water of tropical & subtropical Indo pacific.
    Feeds on fishes ,crustaceans, cephalopods & fish eggs.
    Breathes at 70 to 150 seconds intervals.
    Usually dives for an average of 30 to60 seconds but larger dives up to 12 minutes have been recorded.
    Swim rate recorded up to 25 kms/hour.
  • 11. Physical behavior(contd)
    Irrawadi dolphins are less active than other dolphins
    Only the uppermost part of dorsal fin becomes visible during a slow rolling dive
    They never bow ride
  • 12. Breeding behavior
    Sexually mature around 4to 6 years age
    Gestation period is 14 months
    In Semeyang lake/Mahakam river(Malaya) mating season recorded to be April toJune
    But in Jakarta calves borne between July to december
    New borne measures 96cm,body weight 12.3kg.Body weight at weaning aapx.45kg.
    Though calves consume fish at 6months age but nursed up to 2 years
  • 13. Origin
    Ayeyarwady river or Irrawaddy river which flows from north to south in Myanmar.
    Name derived from the Sanskrit word Iravati(minor Goddess in Indian mythology) or from her son Airabat the elephant
    Irrawaddy is the largest river of Burma about 2170 km long
  • 14. Panoramic view of Irrawaddy river
  • 15. Panoramic view of Irrawaddy river
  • 16. World wide habitats & population
  • 17. Panoramic view of Irrawaddy river
  • 18. Bangladesh as fresh,brackish & salt water habitat
    Sundarban delta
    Mangrove forest
  • 19. Chilika lake as brackish water habitat
    Chilika near sea mouth
  • 20. Panoramic view of inner Malampaya sound (Philipines)Brackish water habitat
  • 21. Brackish water habitat of Sangkhala lake(Thailand)
  • 22. Categorization of IUCN red list
    Ex- Extinct
    Ew- Extinct in the wild
    Cr- Critically endangered
    En- Endangered
    Vu- Vulnerable
    Lower list
    NT- Near threatened
    LC- Least concerned
    Cd- Conservation dependant
  • 23. Analysis of threat as per IUCN red list
    Irrawaddy dolphin is classified as VULNERABLE
    on the IUCN red list and listed in appendix-1 of
    CITES (Conservation of International trade in endangered species)
    In Mahakam river & Malampaya sound classified as
    critically endangered
  • 24. Threats
    Irrawaddy dolphins are more susceptible to
    human conflicts than most other dolphins
    who live farther in the ocean.
    Drowning in gillnets is the main threat throughout their range.
    Majority of reported deaths in all subpopulations is due to accidental capture
    and drowning in gill nets, dragnets, bottomset crab nets(in philipines).
  • 25. Gillnetting the No 1 threat forIrrawaddy dolphin
  • 26. Threat:Chilika experience
    Author has conducted post murtem of 10 dead dolphins between2005 to 2008.
    4 were putrified enough to opine any cause of death.
    5 deaths are due to traping followed by drowning in gill nets bearing injuries on tongue,base of the tail and skin exfoliations.
    1 death is due to lungs desease (focal necrosis
    of lungs)
  • 27. Decomposed dolphin
  • 28. Lungs of dead Irrawaddy dolphin with focal necrotic lesions
  • 29. Researchers working on threat analysis & conservation strategies
  • 30. Threat:Chilika experience
    Unregulated fishing
    Introduction newer varieties of fishing nets which are almost invisible under water.
    Motorized propeller boats, large in number
    Tourist boats approach much closer to dolphins, even sometimes chase them.
    Pollution of water, change in salinity, change in water temperature and siltation are less emphasized.
  • 31. Ongoing conservation initiativesChilika experience
    Mapping dolphin population, distribution and
    movement by using GPS.
    Imposition of fines on gill and seine netting in Satpada region.(Orissa marine fisheries regulation act)
    Fines on tourist boats found chasing dolphins
    Ongoing training in dolphin watching guide- lines by CDA funded by WDCS.
    Distribution of booklets and pamphlets on sustainable fisheries
  • 32. Action plan
    Establishing core conservation areas where gillnets and motorized boats are to be banned.
    Promoting net attendance rules and providing training on safe release of entangled dolphins.
    Providing alternative or diversified employment to gillnet fishermen.
    Research & development with acoustical deterr-ants and reflective nets.