More Chelidonura feeding

October 7, 1998
From: Cory Pittman

Dear Dr. Rudman,

I read your request for observations of Chelidonura feeding behavior shortly after returning to Hawaii for my fall collecting session. That started me thinking about it and, since I often find both small Chelidonura spp. and small flatworms while sorting algae washes, I thought I'd set up a few "encounters" and see what happened. :)

I added a pair of Chelidonura fulvipunctata (6 & 8 mm) to a small dish containing four 1.5-2 mm acoelamate flatworms of the species that Poulter tentatively identifies as Convoluta sp. in section two of Reef and Shore Fauna of Hawaii, 1987. Over a few minutes, I watched them eat three of the worms (the other "disappeared" when I wasn't looking). Their feeding reflex seemed quite extraordinary for an Opisthobranch. On contact with the sensory hairs, the worms were "inhaled" with a speed comparable to the feeding strike of a scorpion fish, i. e., much too fast to make out any details of the movement. So, they certainly responded to that species. Whether it's "on the menu" normally is still open to question, however, since (in at least two of the cases) they regurgitated the crushed remains of the worm about 15-20 seconds after taking it. It may be close enough to their normal prey to trigger their feeding reflex but proves unpalatable after ingestion (perhaps due to some defensive chemical?). Then, again, something else may have triggered regurgitation since my small, well-lighted dish differs considerably from their natural environment.

Later, I added another C. fulvipunctata to a dish with half a dozen 2 mm worms of a different, but undetermined, species. In that case, the Chelidonura totally ignored the worms through several "encounters".

I also offered Convoluta sp. to C. hirundinina with variable results. Most of the time, the Chelidonura ignored the worms. A couple of times, however, the worm was partially engulfed or "tasted" before being rejected. Once, it was completely "inhaled" with a speed comparable to the C. fulvipunctata trials then immediately "spit out", apparently unharmed. Perhaps, evolving an early rejection response to Convoluta sp. would make sense for C. hirundinina if the worm is toxic or distasteful.

I'll try a few more pairings as opportunity permits and see if I can find something that they'll "keep down". :)

By the way, over the years, I've seen many interactions between Chelidonura spp. and a wide variety of other organisms (mollusks, polychaetes, etc.) without triggering their feeding reflex.

I hope this is of interest. Best wishes for your recovery.

Sincerely,

Cory Pittman
temporarily from norm@maui.net

norm@maui.net

Pittman, C., 1998 (Oct 7) More Chelidonura feeding. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/248

Thanks for the observations Cory.

This is the sort of information which usually slips through the net. Not enough for a publication so what do you do with it? I had hoped the Slug Forum would become a place where we could share this sort of information and you contribution is a great example. As I will be leaving messages untouched (apart from correcting typos if I spot them) I see no reason why messages in the Forum cannot be cited in publications.

Your observation of the speed with which Chelidonura "inhales" its prey fits with its anatomy. Most species of the Aglajidae (except Odontoglaja guamensis) have a very modified foregut in which the radular teeth are lost. In species of Aglaja and most Philinopsis the buccal bulb is large and partially everts during feeding to envelop their prey (Bubble Shells and other opisthobranchs). In contrast, species of Melanochlamys and Chelidonura have a very rigid muscular buccal bulb which acts as a suction pump. I have watched Melanochlamys cylindrica in New Zealand sucking in polychaete worms at the blink of an eye .. much like eating spaghetti. I guessed species of Chelidonura, with a very similar shaped buccal bulb, would also suck in its prey and your observations certainly confirm that.

I'll post some more pictures of aglajids on the Forum in the near future. They are an interesting group. Thanks again for sharing your observations with us. ... Bill Rudman.

Rudman, W.B., 1998 (Oct 7). Comment on More Chelidonura feeding by Cory Pittman. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/248

Factsheet

Chelidonura varians

Related messages

  1. Chelidonura varians - laying eggs in an aquarium.
    From: Kim Schrier, April 21, 2010
  2. Re: Chelidonura varians in aquarium
    From: Robin Jerome, December 3, 2009
  3. Re: Chelidonura varians in aquarium
    From: Bill Brown, August 26, 2009
  4. Re: Chelidonura from Mayotte, Indian Ocean
    From: Sylvain Le Bris, January 30, 2009
  5. Re: Chelidonura varians in aquarium
    From: Beck None, October 7, 2008
  6. Chelidonura varians - mating behaviour
    From: Kamal El Tawil, September 19, 2007
  7. Philinopsis gardineri? from the Red Sea
    From: Dany Porras, July 26, 2007
  8. Chelidonura varians - strange behavior
    From: Erwin Kodiat, June 22, 2007
  9. Chelidonura varians from Bali
    From: Danny Van Belle, January 26, 2007
  10. Chelidonura varians from sthn Queensland
    From: Ian Banks, May 4, 2006
  11. Mating Chelidonura varians
    From: Erwin Kodiat, January 16, 2006
  12. Chelidonura varians from Bali
    From: Erwin Kodiat, December 6, 2005
  13. Chelidonura varians mating
    From: Mary Jane Adams, February 14, 2005
  14. Chelidonura varians in aquarium
    From: tlp, December 4, 2003
  15. Chelidonura varians from Sabah, Malaysia
    From: Asther M. Lau, September 6, 2003
  16. Re: Chelidonura varians - shipping stresses?
    From: James Urquhart, June 25, 2003
  17. Re: Chelidonura varians - shipping stresses?
    From: James Urquhart, June 24, 2003
  18. Chelidonura varians - shipping stresses?
    From: James Urquhart, May 28, 2003
  19. Re: Chelidonura varians - trailing behaviour
    From: Roberto Sozzani, May 21, 2003
  20. Re: Chelidonura varians - trailing behaviour
    From: Roberto Sozzani, May 20, 2003
  21. Chelidonura varians - trailing behaviour
    From: Leanne & David Atkinson, May 19, 2003
  22. Chelidonura varians egg laying
    From: Joe Yaiullo, April 22, 2003
  23. Chelidonura varians - larval culture
    From: Joe Yaiullo, April 9, 2003
  24. Chelidonura varians from Lord Howe Island
    From: W.B. Rudman, January 9, 2003
  25. Chelidonura varians - Mabul Island, Malaysia
    From: Richard Houghton, September 3, 2002
  26. Aquarium flatworm control
    From: Victor Hernandez, April 3, 2002
  27. Chelidonura varians from Indonesia
    From: Stuart Hutchison, March 9, 2002
  28. Re: Slug to control photosynthetic flatworms
    From: Patrick Webb, March 9, 2002
  29. Re: Slug to control photosynthetic flatworms
    From: Mark, January 25, 2002
  30. Re: Need Slug that will help with Flatworms
    From: joe, September 7, 2001
  31. Slug to control photosynthetic flatworms
    From: Darrell Gibson, September 7, 2001
  32. Need Slug that will help with Flatworms
    From: D. Scott Morrison, June 17, 2001
  33. Juvenile Chelidonura from SE Sulawesi
    From: Lindsay Warren , June 13, 2001
  34. Planaria-eating nudibranch?
    From: Drew Dram, April 2, 2001
  35. Chelidonura feeding observations
    From: Julian Sprung, December 22, 2000
  36. Re: Where to get Chelidonura varians
    From: Scott Crumpton, June 10, 2000
  37. Re: Where to get Chelidonura varians
    From: Gary J. Robinson, February 14, 2000
  38. Re: More on Chelidonura feeding
    From: Cory Pittman, February 8, 2000
  39. A nudibranch that eats Flat Worms
    From: john, December 10, 1999
  40. control of flatworms in marine aquarium
    From: Roger, May 29, 1999
  41. Red flatworm-eating Sea Slug
    From: pat, April 14, 1999
  42. Re: Where can I get Chelidonura varians?
    From: Donna Stimetz, March 29, 1999
  43. Where can I get Chelidonura varians?
    From: Paul Hranitz, November 30, 1998
  44. Chelidonura feeding
    From: Davide & Giovanni, October 14, 1998
  45. Reference for Chelidonura feeding
    From: Davide Giovine, October 8, 1998
  46. Re: Chelidonura feeding
    From: Peter Firminger, September 18, 1998
  47. Chelidonura feeding
    From: Davide & Giovanni, September 8, 1998

Show factsheet and all related messages