young, 1.5 mm
Julia zebra Kawaguti, 1981
|Maximum size: 4.7 mm
(extrapolated from shell length).
a brownish-green shell with narrow, radiating, dark
brown stripes and cloudy white patches. The hinge tooth is
proportionately smaller and more circular than in Julia
exquisita and Julia sp. #2. The animal is
brownish-green flecked with white and with dark brown bands on top of
its head. The "butterfly-shaped" cream patch outlined in brown that
surrounds the hinge is the result of pigment showing through the
partially translucent shell. (Note 1)
Julia zebra is a
common species found in protected to exposed rocky habitats at depths
of < 1 to 15 m (< 3 to 49 ft). Although diurnal, it's seldom seen
due to its small size and cryptic coloration. Alison Kay found it in association with the green algae Microdictyon in 1962. (Kay, 1962c)
Big Island, Maui, Oahu, Kauai, French Frigate Shoals and Midway: widely
distributed in the
Indo-Pacific and possibly the eastern Pacific.
beach drift in the eastern Pacific and held
California Academy of Sciences under the name Julia thecaphora (Carpenter, 1857)
appear identical to those of the Indo-Pacific Julia Zebra.
Presumably, that name
would have priority if confirmed with live material. Live animals
photographed at Easter Island also appear identical to Hawaiian
material. In southern Japan,
many animals lack all or most brown pigment. However, the
"butterfly-shaped" marking on the hinge in live animals and the smaller
size in shells still appear to distinguish those animals from J. exquisita. Live animals were probably first recorded in Hawaii from Koloa, Kauai by Alison Kay in April, 1962. (Kay, 1962c)
3.6 mm: Hekili Point, Maui; March 22, 2006.
Observations and comments:
1: Shells of this species show
moderately strong red fluorescence under ultraviolet light (395 nM),
most prominently when worn.