Found throughout the tropical and subtropical Indo-West Pacific. It is found intertidally and in the shallow intertidal through most of its range but at the temperate extremes it is usually found subtidally (Japan, New Zealand).
Shelly Beach, Manly, Sydney, New South Wales. October 1986. (Shell length 15mm). PHOTO: Bill Rudman.
Bullina lineata shows an interesting transition stage between the heavily shelled acteonids, such as Acteon and Pupa and the more lightly shelled hydatinids, such as Hydatina physis whose bright colourful animal dominates its body plan. The Family Bullinidae has a mixture of anatomical features, some common to the more primitive Acteonidae, and some to the Hydatinidae.
Bullina lineata retains a thin operculum and is able to retract completely back into its shell. Rudman (1971, 1972) suggested that the similarity of its foregut anatomy to that of Hydatina made it reasonable to assume that Bullina eats polychaete worms. Taylor (1986) reported the remains of sedentary cirriform polychaetes in the gut, which suggests that like Hydatina, they feed on cirratulid polychaetes. See photos of radular teeth.
• Gray, J.E., (1825). A list and description of some species of Shells not taken notice of by Lamarck. Annals of Philosophy, or Magazine of Chemistry, Mineralogy, mechanics, and the Arts; by T.Thomson. New Series (Ed. R.Phillips), 9: 134-140, 407-415.
• Rudman, W.B. (1971) The genus Bullina (Opisthobranchia, Gastropoda) in New Zealand. J. Mal. Soc. Aust. 2(2): 195-203.
• Rudman, W.B. (1972) Studies on the primitive opisthobranch genera Bullina Ferussac and Micromelo Pilsbry. Zoological Journal of the Linnean Society, 51(2): 105-19, 8 figs.
• Taylor, J.D. (1986) Diets of sand living predatory gastropods at Piti Bay, Guam. Asian Marine Biology, 3: 47-58.
Rudman, W.B., 1998 (December 18) Bullina lineata (Gray, 1825). [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/bullline
February 9, 2008
From: Hugues Flodrops
After my last message [#21238], I found at the same place some other "usual" Bullina lineata with the two red spiral lines on the shell. A couple during the night of 6 december 2007 and several (more of six) the night of 18 december 2007 spawning. The front of the head shield is similar.I hope that it is enough to call it B. lineata.
Locality: Etang-salé, Two metres, Reunion Island, Indian Ocean, 6 and 18 december 2007, By night. Length: 18-20 mm. Photographer: Hugues Flodrops.
Flodrops, H., 2008 (Feb 9) Re: Bullina lineata from Reunion Island. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/21365
Although I suspected the animal in your other message was just missing a red line it's a bit hard to be sure without further indications. These more 'normal' animals make me pretty sure it is B. lineata. The shell is a bit more inflated than the ones I commonly see in Sydney, but looking at shells in the museum's collections suggest they often get more inflated as they increase in size, and yours are larger than we normally see in eastern Australia.
It's nice to get a photo of a pair mating.
February 8, 2008
From: Hugues Flodrops
Can you help me once again. I found this Bullina by night. It looks quite like Bullina lineata or B. oblonga but without blue ring around mantle. The colour markings on the shell are also different with one red central spiral.
Locality: Etang-Salé, 1 metre, Reunion Island, Indian Ocean, 28 November 2007, Night. Length: 15 mm. Photographer: Hugues Flodrops.
Thanks and regards.
firstname.lastname@example.orgFlodrops, H., 2008 (Feb 8) Bullina from Reunion Island . [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/21238
It certainly doesn't look like the animal I am identifying as B. oblonga and I am not sure it is B. lineata. Whether the border of the foot is bluish or white seems to be variable, but the shell with a single red spiral line looks unusual as do the long anterior tentacles formed from the front of the head shield. However I think it is best to call it B. lineata until someone can look at its anatomy. It's possible the radula may tell us something.
September 27, 2005
From: Bruce Potter
I found this pretty little Bullina lineata while diving at the old coal loading wharf at Catherine Hill Bay recently. It was only about 15mm long, and was in about 4 meters of water.
Locality: Catherine Hill Bay, NSW, Australia. Depth: 4 meters. Length: 15 mm. 25 September 2005. Sandy beach under old wharf. Photographer: Bruce Potter
email@example.comPotter, B., 2005 (Sep 27) Bullina lineata from New South Wales. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/14842
Although we think of this animal as a sand dweller, it is surprising where it will turn up. It is quite common in New South wales on intertidal rock platforms and tidal pools crawling over algal covered rocks. I guess it will be found anywhere it can find the cirratulinid worms it feeds on.
July 15, 2003
From: Rachel Przeslawski
Hi Debby and Bill,
In response to Debby's question about the range of Bullina lineata, I regularly see them and their spring-like egg masses around Wollongong (SE New South Wales). So it's quite likely they're down in Merimbula also.
Hope this helps!
firstname.lastname@example.orgPrzeslawski, R., 2003 (Jul 15) Re: Bullina lineata in southern New South Wales. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/10448
July 14, 2003
From: Debby Lange
On a trip to a particular beach with the Sapphire Coast Marine Society just south of Merimbula [southern New South Wales, Australia] we found 3 shells of the obviously dead Bullina lineata. Does this mean they are found down here or does it mean they have been washed down from further north?
email@example.comLange, D., 2003 (Jul 14) Bullina lineata in southern New South Wales. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/10443
I suspect that if you have found shells on a beach then the animal was living nearby. Unless a bubble of air got trapped in the shell I can't see them floating far. I will need to check just how far down the eastern Australian coast Bullina lineata has been found but as it is sometimes found in northern New Zealand it is one of those tropical species which can tolerate slightly cooler temperatures.
April 25, 2003
I'd like to know what Bullina lineata eat. I've search the internet high and low for an answer, but all I received was what is it? and don't know! Please help!!
January 16, 2003
From: Allan Saben
Here is a photo of Bullina lineata from Nelson Bay, Port Stephens [Halifax and Flypoint divesites, New South Wales, Australia, December 2002].
firstname.lastname@example.orgSaben, A., 2003 (Jan 16) Bullina lineata from Port Stephens. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/8867
January 7, 2003
From: W.B. Rudman
Location: Middle Beach.
Bill RudmanRudman, W.B., 2003 (Jan 7) Bullina lineata & eggs from Lord Howe Island. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/8822
January 1, 2003
From: Stuart Woodhouse
i was looking through some web pages from southern cross university on their nudibranchs of N.E.N.S.W. and noticed a comment on Bullina lineata stating that it is unable to retract fully into its shell. I was of the understanding that Bullina lineata retained a thin operculum and did have the ability to retract? Am I wrong ??
Thanks for a great site
email@example.comWoodhouse, S., 2003 (Jan 1) Question about Bullina lineata. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/8727
As I say on the Bullina lineata Fact Sheet, it retains a small operculum, and can retract into its shell. Have a look at the Detorsion Page where I discuss how existing primitive shelled slugs illustrate one way the shell has been lost in the opisthobranchs in the process of becoming a 'slug'
December 9, 2002
From: Stuart Woodhouse
thanks for your reply and for identifying this bubble shell for me and the other relevant info for this species was apreciated, congrats on a great site i look forward to spending much time here
firstname.lastname@example.orgWoodhouse, S., 2002 (Dec 9) Re: Bullina lineata. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/8625
December 8, 2002
From: Stuart Woodhouse
I have been a keen diver for years but only recently developed an intrest in nudibranchs
recently while snorkling at Clovelly Pool [Sydney, Australia] I observed a colourful slug crawling across weedcovered rock. Its main body colour was opaque white with a thin iridescent blue line around the circumference. It also had a bulbous section on its back patterned with red/orange lines. This section had the appearance of a small shell. The body length was 25mm aprox. and it was observed at a depth of 2 mtrs. I have looked through many photos with no avail. Could you please shed some light on species, habitas, distribution etc.
Thank you and i look forward to your reply
email@example.comWoodhouse, S., 2002 (Dec 8) Bullina lineata from Clovelly, Sydney. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/8620
May 10, 2001
From: Erik Schloegl
This photo of what I think is Bullina lineata was taken on 28 October, 1998, off Halifax Park, Port Stephens, New South Wales, Australia. The depth was 15m and the water temperature was 18 C. The animal was quite small, under 5mm.
Erik.Schlogl@uts.edu.auSchloegl, E., 2001 (May 10) Bullina lineata from New South Wales. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/4288
Yes your animal is Bullina lineata.
March 19, 2000
From: Bill Rudman
To accompany the photos of the radula of Don Barclay's Bullina sp. 1. here are some photos of the radula of Bullina lineata. The lower photo shows the three innermost teeth on the left side of the radular ribbon and the central region. See the faint elongate plate in the midline which is all that remains of the central tooth. The teeth of B. lineata are more than three times the length of those of Bullina sp. 1 and they have only two or three denticles.
PHOTOS: Alison MIller.
Bill Rudman.Rudman, W.B., 2000 (Mar 19) Bullina lineata radula. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/2116