Bullina sp. 1.
Utulei, west Pago Pago Harbor, American Samoa, 15 January 2000, on coarse sand in about 30cm of water. Shell approx 7mm long. PHOTO: Don Barclay.
Most probably a juvenile specimen of Bullina. See message below.Authorship details
Rudman, W.B., 2000 (January 29) Bullina sp. 1. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/bullisp1
March 19, 2000
From: Bill Rudman,
Hear are some photographs [by Alison Miller] of the teeth of Don Barclay's Bullina from Samoa. It is quite different from the radula of the common Bullina lineata which I have included separately for comparison. The teeth of B. lineata are more than three times the length of those of Bullina sp. 1 and they have only 2 or 3 denticles, compared with 10 or 11 in this species. It looks quite like the radula of Bullina roseana but that species has a much higher spire to the shell.
I was unable to find an operculum, which confirms Don's observation. B. lineata, on the other hand does have an operculum.
I also found the stomach swollen with food - about 20 small worms, each about 5mm long. On examination they turned out to be all of the same species of the polychaete worm family Ctenodrilidae, a group recently separated from the Cirratulidae, and of which we know very little. Whether Don's Bullina had specifically chosen only this species to eat, or whether is had come across a dense population and was 'filling up' while the going was good, will have to wait until some more specimens are found. But considering how many specimens of Bullina lineata I have looked at and found nothing in the stomach, this is indeed a lucky find.
This is a species of Bullina, and from the proportions of the shell and protoconch, it is not a juvenile.
Bill Rudman.Rudman, W.B., 2000 (Mar 19) Bullina sp 1 from Samoa. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/2112
February 15, 2000
From: Don Barclay
After you suggested that I revisit the location that produced the first specimen of this bubble shell to look for a larger animal, I did as you suggested, only to find a Mitra species, Scabricola caerulea Reeve, 1844, that I have never found before. I didn't find another Bullina sp. (though I did find the little orange-speckled nudibranch I wrote you about), but the miter find was exciting, nevertheless. Most of my time and interest has been devoted to the Prosobranch gastropods, though I can tell a Flabellina from a Phyllidiella three out of four times...
Anyway, my snorkeling/diving buddy, Randy Hart, and I were scheming on what other locations in American Samoa might produce S. caerulea, and I suggested an area on the east side of Pago Pago Harbor, toward the back, which was similar to the original site with shallow water and coarse sand, in a place that was somewhat sheltered. We decided to try out this location last night, but didn't find any of the miters. However, I did find a second, and slightly larger, example of the red bubble shell.
This animal has the same pink coloration with a sprinkling of white which becomes denser around the shell, but the shell itself is slightly more inflated and the protoconch not so prominent. This shell measures approximately 9mm, which is two millimeters larger than the first specimen, and the animal's total length at maximum observed extension was 21mm. This shell also appears to be very thin, and doesn't show any inclination to thicken and become anything that looks very different in the short term. If the shell continued to expand as the animal grew at its current expansion rate, it would be quite a large bubble shell by the time it added one more whorl.
This animal was collected on 8 February 2000, at 0130 local time, crawling on coarse sand in a slightly silty area, in 50cm of water, 20 meters from shore and 100 meters southeast of the boat ramp in Aua village, back (east side) of Pago Pago Harbor, American Samoa. This was an hour before low (+0) tide, with a dark moon (new +3 days).
Thanks for the Pupa nitidula photos. They may have solved one of my mysteries, but they may have presented another (like, whether these small, slender, white to yellowish acteonids that I've been calling P. nitidula are actually another species). The one you posted is exactly like the ones I find in Tonga, but I don't find anything exactly like it in Samoa.
Pago Pago, American Samoa
Barclay, D., 2000 (Feb 15) Re: Red Bubble Shell from Samoa. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/1880
I'm glad your diligence resulted in a nice mitrid find. And thanks for the extra photos of the Red Bubble Shell - we now have a wonderful collection of live animal shots. I think it is a Bullina but will wait until I can look at the anatomy of the specimen you are sending. Perhaps you should send a few of the thin Pupa over as well so I can identify it for you.
January 31, 2000
From: Don Barclay
Greetings from Pago Pago.
This small animal was collected just before midnight on 15 January 2000, crawling on coarse sand near shore, Utulei, west Pago Pago Harbor, American Samoa, in about 30cm of water. I haven't been able to locate a photograph of this little bubble on the internet, and it is not figured in any of my conchological references or other books. The shell is about 7mm long, the entire animal about 18mm. At first glance the shell is reminiscent of some species of Bullina, but it is extremely thin. The Conch-L crowd was unable to help me on this one, but perhaps you can put a name on the little fellow.
Thanks for your time,
Barclay, D., 2000 (Jan 31) Red Bubble Shell from Samoa. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/1810
From its size I suspect your animal is a juvenile. The animal has similarities in shape to species of Hydatina and to acteonids such as Maxacteon. In colour it also looks like the pink form of Pupa nitidula, which I have just added to the Forum, but the shell of that species is quite smooth and the shape of both the shell and animal rather different.
The shape of the shell, and the presence of the pitted or beaded sculpture is characteristic of the genus Bullina but I can't be sure of the species. There are a number of species with red or reddish marks on the shell in including the widespread Bullina lineata. The sunken spire on your shell looks quite like that of Bullina nobilis but you could only be sure with a larger animal.
Keep a watch out, with luck you may find a larger animal.