14 November 2011

All about Ovulids of Singapore!

Wong Hoong Wei's awesome paper (pdf) on our fabulous false cowries has been published on the Raffles Museum website as an ebook. Ovulids are snails that live on sea fans and other reef animals, and are perfectly camouflaged on their colourful hosts.
This is a great resource for these fascinating snails! Not only a checklist with detailed descriptions, but also lots of interesting facts and wonderful photos!

The living ovulids are amazing to behold, IF you spot them in the first place. This is because they blend in perfectly in shape and texture with their living hosts. It's great that Hoong Wei has included many photos taken by ordinary people of ovulids on our wild shores.

What are ovulids?
These tiny snails belong to Family Ovulidae and are found on other living reef animals such as sea fans and soft corals. Superficially, they look like cowries (which belong to a different Family Cypraeidae), so ovulids are sometimes called false cowries. Many have long narrow pointy tips shells so they are sometimes also called spindle cowries. These tiny snails often eat their hosts!
False cowrie in pink flowery soft coral
Can you spot the fat False cowrie?
Beneath it, the white lumps might be its eggs!
How many ovulids do we have?
According to Hoong Wei, "in total, 44 species are recorded from Singapore, which is remarkable considering that massive coastal reclamation works in the 1960s left waters surrounding the island with chronic sedimentation levels."

Another fascinating feature of our Ovulids highlighted by Hoong Wei is that in Singapore, they are found in shallower waters than elsewhere in the region.
Red spindle cowrie (Ovulidae)
These tiny spindle cowries are easily seen at low spring tide
on shores like East Coast Park!
Ovulids are tricky to identify from just photographs
Hoong Wei explains: "other than a few exceptions (e.g., Calpurnus verrucosus, Ovula Ovum), many species are known to be notoriously variable when it comes to external appearance. In addition, few studies have been done to extensively investigate the extent of variablility within a species. Hence, identification to the species level based on photographs of animals in situ alone is difficult."

At the same time, Hoong Wei encourages us to photograph and share our photos of ovulids because "A number of photographs of living animals in situ shared by SCUBA divers and marine enthusiasts did not seem to correlate with any of the species included herein, and further investigation and examination of specimens yet to be found might shed light on whether these photographs represent species not yet known to occur in Singapore waters." and that "It is highly likely that corrections, new records, and ecological observations will be added to this checklist in the near future."

So keep looking for these amazing snails on our shores!

Read the full paper here: Wong, H. W., 2011. The Ovulidae (Mollusca: Gastropoda) of Singapore. Raffles Museum of Biodiversity Research, National University Singapore, Singapore. 58 pp. Uploaded 10 Nov.2011. [PDF, 3.08 MB]

Thank you Hoong Wei for this labour of love that sheds so much light on these fabulous creatures!

More about Ovulids on the wild fact sheets which have been updated with Hoong Wei's information and identification.

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