June 19, 1999
From: Monica Sullivan
Here is a third bit of info I observed in SE Sulawesi, Indonesia, last year (Operation Wallacea )
I was having some ear trouble for a few days, so I couldn't dive but I managed to set up a small research project on chelidonurids, feeding, tides, etc. for a student. I took a lot of specimens up to the lab for binocular i.d.. It wasn't until I had a petri dish full of them under the microscope that I saw one of the chelidonurids follow the exact trail of a flatworm, until it caught up with it. I watched it with great excitement as what can only be described as it 'unzipped' the worm and sucked out its interior. It did not kill the worm, but instead allowed it to crawl off. Are you familiar with this behaviour?
firstname.lastname@example.orgSullivan, M., 1999 (Jun 19) Chelidonura - feeding observations. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/955
Any idea of the identity of the chelidonurid? and could you give us some indication of size?
I have been trying to find what chelidonurids fed on for years and it was only some messages last year on aquariists wanting Chelidonura varians to eat infestations of red flatworms that finally provided an answer to its food. The prominent sensory bristles on either side of the mouth suggest they track their prey so your observation of them following the trail is intersting confirmation. (See the pages on Chelidonura hirundinina and Chelidonura inornata for pictures of the sensory bristles).
I'm not sure I understand how they suck the flatworm's organs out and leave the skin as they have no biting organs, relying completely on suction to injest their prey. Perhaps they sucked out a recent flatworm meal?