A "miracle baby" zebra shark will celebrate its second birthday next Thursday, when Singapore celebrates its 53rd National Day. Out of nine zebra shark eggs that were picked up and incubated by S.E.A. Aquarium, this was the only one that survived. Also, aquarists believe that the shark, Vanda, was hatched asexually - without a male parent - through a natural process called parthenogenesis. Experts say the female's ability to produce offspring from an unfertilised egg is an invaluable survival mechanism in the absence of a suitable mate. Zebra sharks are also an endangered species. Visitors can celebrate Vanda's birthday from Aug 9 to 12. There will be a talk on sharks at 3.30pm and an underwater flag "dive-past" - as opposed to a "fly-past" - at 3.45pm.