Circumglobal in temperate and tropical waters.
Collaroy Beach, Sydney, New South Wales. February 1987. 35mm long alive. Photographed from above to show foot - both Glaucilla and Glaucus float upside down.
PHOTO: Bill Rudman.
Both Glaucus and Glaucilla appear to be "monotypic" genera. That is each genus has only one species. The main external difference is that in Glaucus the cerata are arranged in a single row in each arch while in Glaucilla there are multiple rows. The biology of the two species is discussed under Glaucus atlanticus.
See photos of pelagic egg strings.
• Bergh, L.S.R. (1860). Om Forekomsten af Neldefiim hos Mollusker. Vidensk. Meddel. Naturh. Foren. Kjöbenhavn, p. 309-331, pl. 8
Rudman, W.B., 1998 (November 6) Glaucilla marginata Bergh, 1860. [In] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/factsheet/glaumarg
Glaucilla marginata from sthn Queensland
From: Gary Cobb, February 13, 2009
Re: Tiny, elaborate creature at Stradbroke Island, Queenslan
From: Rob Blackmore, January 20, 2009
Re: Nematocysts in Glaucilla
From: Julia Busch, January 21, 2001
Nematocysts in Glaucilla
From: Julia Busch, January 20, 2001
Glaucilla marginata - any east Pacific records?
From: Orso Angulo, January 29, 2000