Acteocina inculta
(Gould, 1846).
Order: CEPHALASPIDEA
Superfamily: PHILINOIDEA
Family: Scaphandridae
DISTRIBUTION
Monterey Bay, California to the Gulf of California
PHOTO
UPPER: Bahia Magdalena, Baja California Sur, in 1 meter (3 feet) on sandy bottom, animal is 3.2 mm long. Photo: Orso Angulo.
LOWER: Gizzard plates of a specimen of A. inculta from off San Diego, California, USA. Photo: Kelvin Barwick
Behrens (1991) states that "it is common, plowing around on mudflats in bays and lagoons from Monterey Bay, California to the Gulf of California".
Reference:
• Gould, A.A. (1846). Shells collected by the United States Exploring Expedition under the command of Charles Wilkes. Proc. Boston Soc. Nat. Hist., 2: 153-171.
Rudman, W.B., 2001 (March 2) Acteocina inculta (Gould, 1846).. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/acteincu
Related messages
Re: Retusa? from Baja California
March 6, 2001
From: Ron Velarde
Dear Bill,
In answer to your question, in the specimens of Acteocina that we get from off San Diego, the spire is extremely variable. I suspect that the spire is relatively fragile in the juveniles and the variability in the adults reflect this condition.
The following species of Acteocina are found off San Diego:
• A. inculta (Gould,1856)-embayments
• A. culcitella (Gould, 1852)-shallow offshore,<30m
• A. eximia (Baird, 1863)- deep offshore,>30m
• A. harpa (Dall, 1871)- offshore
The first three species are very common in our benthic samples and the distibutions are well documented. A. harpa is less abundant and thus its distribution is less certain.
Ron Velarde
rgv@sdcity.sannet.gov
Velarde, R., 2001 (Mar 6) Re: Retusa? from Baja California. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/3916Thanks Ron,
Bill Rudman
Re: Retusa? from Baja California
March 4, 2001
From: Ron Velarde
Dear Orso / Bill,
Your animal looks like Acteocina inculta (Gould, 1856). Behrens (1991) states that "it is common, plowing around on mudflats in bays and lagoons from Monterey Bay, California to the Gulf of California".
I attempted to attach an image, taken by Kelvin Barwick, of the gizzard plates of a specimen of A. inculta from off San Diego.
Hope this helps.
Ron Velarde
rgv@sdcity.sannet.gov
Velarde, R., 2001 (Mar 4) Re: Retusa? from Baja California. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/3892Thanks Ron,
Variable shell-shape is one other thing that makes me nervous trying to identify some of the liittle bubble-shells. Which is why local knowledge of populations is so important. In Dave Behrens' photo the spire is quite a bit more pronounced then in Orso's photo. Is this variable in Acteocina inculta? Some species of Retusa are also very variable in shell shape.
best wishes,
Bill Rudman
Retusa? from Baja California
February 28, 2001
From: Orso Angulo
Hi
Im trying to identify this cephalaspidean, as for now I have named as Retusa sp. or Cylichna sp. But I'm not sure about it. Could someone in the branch comunity help me?
The animal was collected in Bahia Magdalena, In Baja California Sur, in depth of 1 meter (3 feet) on sandy bottom, the size of the animal is 3.2 mm.
Thanks,
Orso Angulo
mol@lapaz.cromwell.com.mx
Angulo, O., 2001 (Feb 28) Retusa? from Baja California. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/3803Dear Orso,
I am afraid these little bubble-shells are very difficult to place in a genus or even a family unless you can look at their anatomy. I would guess that your species is possibly a species of Retusa or perhaps Acteocina. If you are adventurous, have a look and see if it has a radula or gizzard plates. If it has, and you can describe them for us, we could almost certainly suggest a genus for you.
If we are lucky, one of our Californian colleagues may recognise it.
Best wishes,
Bill Rudman
