Bootlace and ribbon worms - Nemertea
Brown animal: Notospermus tricuspidatus (Quoy & Gaimard). Up to 300mm long unstretched, its long sticky proboscis is often shot out when the worm is picked up. It can stretch tp 3 or 4 meters when picked up.
Orange animal: Gorgonorhynchus repens. Much smaller, (50mm unstretched), this species is unusual in having a proboscis consisting of many tubes. When the proboscis is everted, it looks very like a terebellid polychaete worm.
Both found at Long Reef, Sydney, NSW, Australia. May 1995. Photos: Bill Rudman.
Nemertine worms are also called boot-lace or ribbon worms because of their shape. They are voracious carnivores usually eating living prey but also able to feed on dead fragments. They feed by shooting out a very long thin proboscis which is either sticky or has poisonous hooks. The prey is entangled in the proboscis and drawn towards the worm's mouth. The body wall musculature of nemerteans is not well developed and when picked up they can stretch to many times their original length.
Rudman, W.B., 2002 (July 6) Bootlace and ribbon worms - Nemertea. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/nemertea
September 3, 2005
From: Douglas Hansen
I have occasionally found these creatures while diving in Monterey. I found this one fully exposed on a rocky face in about 70 feet of water. I usually see only a portion of these creatures sticking out of a crevice. This one appeared to be approximately one meter long! It is only about one-quarter of an inch (or less) wide. The photograph is of what appears to be the anterior end. I have not seen anything like it in any of the books that I have. Can you give me some idea of what this might be?
Locality: Point Lobos State Reserve, California, USA. Depth: 70 feet. Length: 1 meter. 18 July 2005. rocky wall. Photographer: Douglas Hansen
email@example.comHansen, D.S., 2005 (Sep 3) Unidentified Creature from Monterey, California. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/14689
I know I should resist the temptation to spend time on non molluscan animals but some are quite fascinating. This is a carnivorous nemertine worm, a phylum of animals which are commonly known as bootlace or ribbon worms for obvious reasons. We have some spectacular photos from Dong Bum Koh of one eating a sea hare [message #13659]. Your animal is identified as Tubulanus sexlineatus (Griffin) and known from Alaska to sthn California. I had a quick look on the web today and found many records of a species with this name from both the Nth American and European Atlantic coast. To my unturored eye the Atlantic one looks quite different, so as I don't know where the animal was originally described, I don't know whether the name of the Californina animal is correct or not. As I said, its probably best if I don't venture outside the field of molluscs.
July 11, 2002
From: Bill Rudman
Thanks for the multiple messages I have received with photos and links to Bonellia and other echiurans. As much as I might like to, time etc., prevents me from turning the Forum into a 'mysteries of the sea' site. With Cory's comments I am sure we have pointed Rick in the right direction.
July 8, 2002
From: Rick Hennis
This creature came in on some live rock out of the Sea of Cortez. It comes out about 5min after lights out.
Please help me identify.
firstname.lastname@example.orgHennis, R., 2002 (Jul 8) Mystery from the Sea of Cortez. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/7418
This is a Nemertean worm (also known as a Ribbon Worm, or Bootlace Worm}. They can grow very long and can change shape from being a short, fat worm to being an extremely long thin worm. Unlike most worms it does not have a mouth is not at the end of its body but has a long proboscis which can shoot out from a pore about a quarter of the way down the body. I think the third 'arm' in your animal is the feeding proboscis.
July 8, 2002
From: Cory Pittman
Off topic, of course, but I have to disagree on the identification of this one. I believe that it's actually the proboscis of an Echiuran. The body of the worm is probably tucked out of sight in a crevice on the right. See photo 717 in Colin & Arneson's Tropical Pacific Invertebrates for a similar view.
Cory@cet.comPittman, C., 2002 (Jul 8) Mystery from Sea of Cortez is Echiuran. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/7471
Thanks for your rapid reply. This mystery is definitely off topic, but I try and steer non-opisthobranch enquirers in the right direction - though in this case perhaps not quite the right direction. My experience with echiurans is largely based on a 20cm long sand-dwelling burrower in New Zealand with a very short proboscis, quite different from these crevice-dwelling tropical forms.
the Echiura are another phylum of wormlike animals which have a feeding proboscis which can, in some species, extend out a considerable distance from the head end of the body. In many species the proboscis is bilobed. Cory is suggesting, that your animal is an echiuran, and what you can see is the proboscis extending out from a crevice in the lower right of the photo and ending in two fatter lobes at the top left. The body is hidden. My suggestion was that the fat bit at the top was a nemertean worm and the long thin bit was its proboscis.
I am sure Cory is correct but one way to check would be to give it a gentle prod and see which way it retracts. If its an echiuran it should retract or partially retract down a crevice in the bottom right. Although this is not a 'slug' please let us know what happens.