Hawaiian Julia zebra
October 12, 2001
From: Cory Pittman
On Maui, shells of Julia zebra Kawaguti, 1981 are common in sand samples that include material from shallow, moderately exposed to exposed, rocky habitats. However, unlike J. exquisita and Julia sp. 1 they are also common in samples that include material from moderately protected, back-reef habitats. All told, I've seen several thousand valves with a maximum shell length of 3.4 mm. I've also picked up about 73 live animals in algae washes from depths of less than 1 m to 15 m (most of my washes have been in moderately protected areas). The color is highly consistent with narrow, continuous brown bands on the anterior portion of the shell and broader, fainter bands on the posterior portion. The bands are superimposed over random white blotches. In live animals, there is extensive brown pigment on the head and rhinophores. The hinge is relatively small and constricted. The central, tooth-like knob is nearly circular in cross section with only a slight indentation on its posterior margin. [See separate message for detailed photos of shells].
Although not a synonym of J. exquisita, it might ultimately turn out to be a synonym of J. thecaphora Carpenter, 1857. Beach-worn shells of that species from the Gulf of California housed at the California Academy of Sciences appear indistinguishable from Hawaiian shells of J. zebra.
I've found shells in sand samples (sent to me by Pauline Fiene-Severns and Jerry Flora) from Abemama Atoll, Midway Atoll, Raratonga and Magaia(Cook Islands).
The live shot is of a 2.5 mm animal collected in an algae wash at Napili Bay, Maui on July 3, 1996. It was at a depth of less than 1.5 m. The hint of blue on the eyes is an artifact of lighting. The shell photos are of a closely matched (though slightly worn) pair 2.9 mm in length. They were in a sand sample collected from beach drift at Makuleia Bay, Maui in 1983.
Cory Pittman
cory@cet.com
Pittman, C., 2001 (Oct 12) Hawaiian Julia zebra. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from http://www.seaslugforum.net/find/5374Related messages
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Shell of Julia zebra
From: Cory Pittman, October 12, 2001
