16 November 2010

Wildfact updates: Marvellous molluscs!

The belated updates include Tiger cowries!! Several were spotted by the team this year on our explorations of remote submerged reefs! This one was seen on Terumbu Raya and shared by Chay Hoon and Kok Sheng.
While Mei Lin shared THREE Tiger cowries seen on Pulau Biola! Tiger cowries (Cypraea tigris) are more often seen by divers, such as at Pulau Hantu, like this huge one shared here by Mei Lin.

Another first time find was also on a submerged reef that we visited for the first time. It's the pretty Strawberry cockle (Fragum unedo).
Thanks to James Box I learn that this snail we've been seeing recently on our sandy shores is the Cat's ear pyramid snail (Otopleura auriscati)!
Cat's ear pyramid snails (Otopleura auriscati)
But most helpful in my attempt to figure out snails is Siong Kiat's and Henrietta's awesome Preliminary Checklist of The Molluscs of Singapore (pdf) on the Raffles Museum of Biodiversity Research website. Plus various references, I spent several weeks updating the fact sheets and trying super hard to figure out the unknown snails we've seen.

Here's what I think some of them are. Please do let me know if I'm wrong!

I think this one is the Calf moon snail (Natica vitellus). We've been seeing this snail in quite a few locations particularly this year.
We've been seeing this moon snail with a spotted body for some years now. Thanks to JK who suggested it is Gualtieri's moon snail (Natica gualtieriana). But I think it's easier to call it the Spotted moon snail since it's so far, the only moon snail we commonly see on our shores with a very obviously spotted body.
Finally, this pretty moon snail with a pink body and lacy white foot is probably Natica zonalis.
I think this strange leathery flat white thing is the Naked moon snail (Sinum sp.). Usually well embedded in the leathery body is its thin, delicate shell. Because of its shell, it is also called the Ear moon snail or Baby ear moon snail.
Naked moon snail (Sinum sp.)
I think this is the Pear-shaped cowrie (Cypraea pyriformis). We've been seeing these regularly at Beting Bronok over the years.
I think these tiny white snails that we sometimes see on our sea stars are Ulimid snails (Family Eulimidae). Ulimid snails are parasitic. Apparently, they stick their proboscis through the body wall and suck on the host body fluids. Eew!
This clam that is sometimes seen on our reefs might be the Thorny oyster (Family Spondylidae).
Thorny oyster (Family spondylidae)
The little dead clams that we often see washed up on the shore that look like little butterflies are probably Surf clams or Donax clams (Family Donacidae).
Various clams washed ashore
Surf clams actually do surf the waves! They migrate up and down the shore by floating with the waves and then rapidly burying themselves. By doing so, they are able to move up and down the shore with the tides thus exploiting food found in the different shore zones. This also helps them avoid predators such as Moon snails.

And these little white clams that we see under stones are probably Scintilla clams (Scintilla sp.).
Scintilla clam (Scintilla sp.)
The mantle sometimes covers the entire valves of Scintilla clams. When submerged, little finger-like structures appear from the mantle. Some have a wide 'foot' created from fused mantle edges which they use to hold on to a hard surface as well as to slowly creep about.

Of course besides these, there were lots of other sightings by the rest of the team which I've added to the fact sheets. Because of the lapse of months, there were just too many sightings to consolidate in this post. My apologies.

Thanks to those who found the critters, and who took photos and video clips and shared about them. See all the photos in full glory and read about the recent adventures on these blogs:
I'd gladly include your sightings in the wild fact sheets. Just email me, Ria at hello@wildsingapore.com

4 comments:

  1. Hi Ria,

    It's very heartening indeed to realise that Singapore still has a great molluscan diversity. Keep up the great work of documenting Singapore's beautiful wilderness, Ria! :)

    Cheers,
    JK

    ReplyDelete
  2. Thank YOU JK for sharing IDs and for your encouragement! Yes, I'm happily astonished by the many marvellous molluscs that we can find on our shores!

    ReplyDelete
  3. Me too, love the eulimids. Though I think the poor sea stars don't like them much.

    ReplyDelete

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