Cyerce cristallina? from Florida

January 26, 2002
From: Linda Ianniello

Here is a photo of Cyerce cristallina from South Florida. It was found at night, off the shore of Deerfield Beach, at a depth of about 15 feet [5 meters]. We have found these animals several times, but they are very difficult to spot as they blend in so well with the surrounding algae. They also don't like light, and will crawl into a hole if the light is left on them for too long. This subject was about 1.5 inches long.
Linda Ianniello

Ianniello, L., 2002 (Jan 26) Cyerce cristallina? from Florida. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Dear Linda,
Thanks for this photo but I have some doubts about this identification. It is another example of the difficulty in identifying West Atlantic animals. Cyerce cristallina(Trinchese, 1881) was originally described from the Mediterranean and specimens from there have a very distinctive colouration. It has also been reported from the Caribbean by Thompson (1977) who reported four related species from Jamaica, Cyerce cristallina, Cyerce edmundsi, Cyerce antillensis, and Polybranchia viridis.

C. cristallina is translucent white with distinct reddish markings on the head and cerata. Thompson says the four species are easily distinguishable externally:
"Polybranchia viridis has tuberculate papillae, while those of the other three species of Cyerce lack tubercles. Cyerce edmundsi has pearl-like swellimg along the free oiuter edge of the cerata, lacking in the other two species. Cyerce cristallina has crimson markings on a white background, while Cyerce antillensis is predominantly drab brown in colour."

From his account I am pretty sure your animal is not C. cristallina but unfortunately I am not sure from the photo just which of the other three your animal is. Hopefully Kathe Jensen will have an idea.

• Thompson, T.E. (1977) Jamaican opisthobranch molluscs I. Journal of Molluscan Studies, 43(2): 93-139,pls.1-3.

Best wishes,
Bill Rudman

Rudman, W.B., 2002 (Jan 26). Comment on Cyerce cristallina? from Florida by Linda Ianniello. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from


Cyerce cristallina

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