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Additional Photos
side
underside
rhinophores
young
violet stalks
on food sponge
mating
egg mass
veligers
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GALLERY
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Thorunna daniellae (Kay & Young,
1969)
Maximum size: about 25 mm
(Hoover, 2006).
Identification:
The
body
of
this small, slender nudibranch is opaque white with
a magenta line (sometimes interrupted) encircling the notum just inside the mantle margin. The
rhinophore stalks are usually translucent (though, sometimes, tinged with violet), with the clubs orange-red on the
anterior side and opaque white on the posterior side. The gills are
opaque white with orange-red tips. In very young animals, the notum
is translucent and has a herringbone pattern of embedded white spicules
beginning between the rhinophores and ending at the gills. It may be distinguished from Thorunna kahuna
by the lack of prominent opaque-white mantle glands around the
posterior margin. It also has an opaque white (rather than translucent
pink) notum when mature and a boundary between the orange and white
pigment on the rhinophores that is angled rather than straight.
Natural history:
Thorunna daniellae
is a moderately common diurnal species found on rocky bottoms. It
occurs at moderately exposed to highly exposed locations from 5-27 m
(16-90 ft) and vibrates its gills. It lays a pale-peach to cream egg
mass that hatches in four to six days in the laboratory and flattens its
branchia while mating. It appears to feed on a variety of sponges. (Note 1)
Distribution:
Big Island, Maui, Oahu, Kauai, Niihau, Midway and Kure: widely distributed in the
Indo-Pacific.
Taxonomic notes:
This
species
was
listed as Hypselodoris
daniellae in Kay, 1979, Kay & Young, 1969 and Kay & Schoenberg-Dole, 1991.
It was named for
malacologist
Danielle Fellows. It's referred to as "Danielle's Thorunna"
in Hoover, 1998 and as
"Danielle's nudibranch" in
Hoover, 2006. It was first reported in Hawaii from Ala Moana, Oahu in
March, 1962 (Kay & Young, 1969). There's some chance that animals with violet rhinophore stalks could be distinct.
Photo: CP: 8
mm: near McGregor Point, Maui; Oct. 9, 2003.
Observations and comments:
Note
1: Four of five animals
associated with a pink sponge in i-Nat photos had interrupted
submarginal lines. The 5th was a "normal" animal paired with one of the
others. Although segregation by food might suggest a cryptic split, the
latter case would argue against it...
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