Pulmonate Slugs from Philippines

January 13, 1999
From: Erwin Koehler

Dear Bill,
Here are the last sea slugs of my trip to the Philippines. The shots were made at BBC, Panglao Is., Nov. 1998 but that is not the place I found them. Some fishermen told to a guest that there are hundreds of sea slugs at the shore at Kalipayan - only at low tide. The guest told it to a dive-guide, this guy told it to me and I walked to Kalipayan (the next settlement)to have a look. I was a little bit late, low tide had passed.

There were many of them, not hundreds but many. Unfortunately my camera did not work because of the humidity. So I couldn't take of them within the original surrounding. They had a strange behaviour: At low tide, when the shore and the plants (which looked like very small Neptune grass in the Mediterranean) ran dry they crawled upon the shore. The sun was burning mercyless - but it seemed as if they didn't mind. I put one of them in the warm water of a very shallow tidepool (depth about 10 cm) and it crawled into the sand. I guess they usually live underneath the sand. I decided to take 5 of them with me to get some shots during the next dive. The reeftop at BBC has a similar surrounding (sand with plants) but it does not run dry at low tide.

There happened the same: All of them crawled into the sand, 3 minutes later no one was left visible. Do you have any idea about the ID and their behaviour (crawling in the sun)? Perhaps a need of oxygen?
Excuse my Germenglish, I hope you can understand what I tried to say.


Koehler, E., 1999 (Jan 13) Pulmonate Slugs from Philippines. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/461

Dear Erwin,
There's nothing wrong with your Germenglish..and its a lot better than my German!

The reason your animals were doing silly things like crawling in the sun and out of the water is that they are pulmonate (ari-breathing)land slugs. Yet another group of snails that have lost their shells. There are a number of pulmonate land snails that live in the marine intertidal. Apart from the onchidiids there are the pulmonate limpets (Siphonariidae) and the ellobiid snails.

Often onchidiids do occur in very large numbers. I suspect the ones you took back to photograph and which crawled into the sand, were in fact looking for a solid base on which to crawl. They do not normally crawl on coral sand preferring a hard surface. There are some species which live on mudflats which do crawl on the mud but in those cases the mud is compacted and relatively solid.

Thanks for sharing some of your Philippines finds with us. If you have a few that you could identify without help that you would like to share they would be welcome.

Bill Rudman.

Rudman, W.B., 1999 (Jan 13). Comment on Pulmonate Slugs from Philippines by Erwin Koehler. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/461

Related messages

  1. Limpet-like slug from New South Wales
    From: Sam Rodely, February 22, 2010
  2. Re: Onchidella celtica from Channel Ids
    From: Frans Janssens, July 22, 2008
  3. Re: Onchidella celtica from Channel Ids
    From: Jean-Yves Monnat, September 22, 2007
  4. Pulmonate slugs from the Caribbean
    From: Phillip Gillette, July 4, 2007
  5. Marine pulmonate slug from India
    From: Doug Eernisse, April 4, 2007
  6. Onchidium from the Arabian Sea
    From: Bhavik Patel, November 16, 2006
  7. Korean slug in intertidal zone
    From: William Churchill, September 6, 2006
  8. Sea slug from Tioman Island, Malaysia
    From: Andrew Lee, February 16, 2004
  9. Re: Onchidiid from Thailand
    From: Kevin J. Caley, April 28, 2003
  10. Dendrodoris? from Siladen, Indonesia
    From: Ginette Allard, December 3, 2002
  11. Re: Onchidella celtica from Channel Ids
    From: Yves Muller, February 18, 2002
  12. Re: Onchidella 'eggs'
    From: Peter Wirtz, February 17, 2002
  13. Onchidella celtica from Channel Ids
    From: Nick Jouault, February 11, 2002
  14. Giant Onchidium from South Africa
    From: Valda Fraser, May 8, 2001
  15. Pulmonate slug? from Maldives
    From: Erwin Koehler, May 4, 2001
  16. Onchidiid from Thailand
    From: Sylvain Le Bris, March 17, 2001
  17. Photo of Onchidium
    From: Stephanie A. Clark, January 13, 1999

Show factsheet and all related messages