SEA Aquarium's ‘miracle baby’ shark turns 5 on Singapore’s National Day
Vanda is one of two “miracle baby” zebra sharks born in Singapore at the Resorts World Sentosa attraction. Hope, the aquarium’s latest baby zebra shark, was born in January.
Vanda, the Singapore-born "miracle baby" zebra shark is turning five on Monday (Aug 9), as Singapore celebrates its 56th National Day.
Born in 2016, she's the first "miracle baby" described as such at Resorts World Sentosa’s SEA Aquarium – aquarists believe that she was hatched asexual without a male parent.
Sharks reproducing asexually is an extremely rare phenomenon. This natural process is called parthenogenesis, which refers to the development of embryos without the fertilisation of eggs. This has been recorded in plants and animals including fish, snakes and lizards, in the wild and under human care.
Among the nine eggs collected and incubated by the aquarists at SEA Aquarium between March and June 2016, only Vanda survived, which made her extra special to the curatorial team.
And she has been under aquarist Kenneth Kwan’s personal care for the past five years.
“I am so happy Vanda has grown up healthily and is now one of the stars of the aquarium," said Kwan. "She is quite shy but also inquisitive and a picky eater! Her favourite foods are squid and prawn. So as part of her fifth birthday celebrations, we've prepared a special iced birthday cake for her, made up of tuna, mackerel, squid, crab and prawn."
"Initially, we thought Vanda would be a one-off birth, but to our happy surprise, sometime in early January this year, we discovered an egg case with a developing embryo," shared Kwan.
That would be Hope, who is also suspected to be born through parthenogenesis in Jan 9. Currently about 80cm long, she is housed in the aquarium’s quarantine area where she is exposed to enrichment activities, such as target feeding.
"We decided to name the baby shark 'Hope' to signify a new and positive dawn for zebra sharks, which are listed as ‘vulnerable’ in the IUCN Red List of Threatened Species,” he explained.
According to Kwan, the recall-and-feed (also known as target feeding) method is what aquarists use to target feed Vanda and Hope. It is a form of animal enrichment activity, which allows aquarists to form closer bonds to the zebra sharks. Eventually, as these bonds form, it allows aquarists to be able to quickly assess the sharks’ well-being and physical health easily.
According to marine life conservation experts, the female’s ability to produce offspring from an unfertilised egg could be an invaluable survival mechanism in the absence of a suitable mate. It is a way of keeping their lineage going for one or two breeding seasons until the female comes across a suitable mate.
Across the world, the numbers of zebra sharks are dwindling as a result of human activities like degradation of coral reef habitats, pollution and overfishing including shark finning.
Zebra sharks are oviparous and females lay large dark brown eggs cases, also called “mermaid’s purses”. Once a female lays her eggs, aquarists will then carefully collect the egg cases to incubate and closely monitor them for embryo development until they hatch.
The eggs can take between four to six months to hatch if an embryo is present, and they are extremely sensitive to water conditions such as temperature, flow and salinity.