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| shelled snails text index | photo index |
| Phylum Mollusca > Class Gastropoda |
| Worm
snail Family Vermetidae updated Oct 10
Where seen? This odd-looking snail is seen in groups on rocks, stones and other hard surfaces. Commonly seen on our Northern shores. Features: Tube opening 1-2cm in diameter, coils 10cm long or more. This amazing snail is NOT a worm. It builds a tube on hard surfaces that appear similar to the tubes built by keelworms. Some species of worm snails seal the opening in the tube with an operculum, others don't. As young snails, the shell they produce appears 'normal', and are free-living and unattached. But they soon attach to a hard surface and the shell produced becomes meandering and coiling. Sometimes confused with keelworms (Phylum Annelida, Class Polychaeta) which are segmented worms that also build coiling hard shells on hard surfaces. Here's more on how to tell apart animals that build hard coiling shells on rocks. What does it eat? A worm snail 'nets' food from the water. A sticky mucus net is secreted from a gland near the foot. This net can extend many times the body length. Elsewhere, it was observed that a vermetid snail with a tube diameter of 5cm had a mucus net 2m long! The animal gathers the mucus and eats it together with whatever tasty bits are stuck on it. The vermetid snail's digestive system is more similar to that of bivalves than other gastropods. Worm snail babies: Male worm snails release their sperm in packets. Female worm snails 'net' these sperm packets in the same way that they gather food. As the sperm packets are hauled near the female's body, the sperm is released from the packet. Or the female may store the sperm to fertilise the eggs later. Eggs are retained inside the tube. They don't have a free-swimming stage and emerge out of the tube as little snails. After crawling about briefly, they cement themselves to a hard surface. Human uses: In Polynesia, they are a traditional food of some coastal people. |
 Changi, Jul 02  Tentacles emerging when submerged Raffles Marina, Apr 05  Changi, Apr 05 |
Although they look like worms, they are actually snails!
 Tuas, Jun 02 |
 Feeding with mucus strands? |
Vermetid snails on Singapore shores
 Tuas, May 05 |
 Changi, Apr 05 |
 Labrador, Mar 05 |
more photos of vermetid snails on Singapore shores
| Family
Vermetidae recorded for Singapore from Tan Siong Kiat and Henrietta P. M. Woo, 2010 Preliminary Checklist of The Molluscs of Singapore.
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