Small-scale restocking of fluted giant clams in Singapore

The giant clam mariculture programme in Singapore began almost a decade ago, with much success and tribulations in cultivating juveniles by hand. Despite the difficulties we face, we still manage to keep numerous small cohorts through the years… One such example is cohort 2007 (the batch that got me started!) – in December 2010, I outplanted the remaining cohort. While there are some failures to this transplant (e.g. not securing the individuals onto substrates, lack of caging facilities, unexpected wave actions crushing the clams, etc…), the successful ones shed light on their survivability on Singapore’s highly urbanised and marginal coral reefs.

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An example of a 2012 cohort of fluted giant clam, Tridacna squamosa.

I like to share with you three individuals that have not only persisted and cope with the sedimented reefs, but have grown so much larger since I last saw them in 2010! (Unfortunately at that time, I wasn’t able to fund my surveys after 2010. I was lucky to have colleagues who still went out to check on them from time to time…). This year, after a very very long hiatus from visiting the site – I finally set eyes on my very first ‘clam progeny’.

A

Not so baby anymore! These 2007 cohort have grown tremendously since transplant in 2010. They are all grown up and ready for procreating their progeny.

When I had first transplanted, they were only a mere 10cm! Look how much they have grown over the past 4 years (and mind you, still growing very well!). I was pleasantly surprised to also see how much other biota have been hosted by the clams on their shell surfaces – soft corals, sponges, ascidians, and even a passing nudibranch! Another interesting outcome of this work is that these individuals can mature much faster when planted out in the sea – all of them reaching up to 30cm already! Well, the next step – natural reproduction! 🙂

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Clam modelling – human scale bars of size and weight! Immense! 🙂 Thank you Kok Sheng for the photos!

This monitoring work would not have been possible without the help of all the intertidal regulars, especially Ria and Kok Sheng who ardently shares with me their clam stories. The clams and I are ever grateful for you guys… 🙂

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