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Additional Photos
solid orange
side
young, 6 mm
feeding
shell
with egg mass
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GALLERY
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Berthellina delicata (Pease, 1861)
Maximum size: 57 mm.
Identification:
This
is a light to dark orange species, sometimes with a few scattered
pale spots on the notum formed by the absence of orange pigment. It has a gelatinous texture.
Natural history:
Berthellina delicata
is a common nocturnal pleurobranchid found in rocky habitats at
protected to exposed sites and, occasionally, in Halimeda kanaloana beds. It occurs
in tide pools and subtidally to depths of at least 9 m (30 ft).
It feeds on a variety of scleractinian corals and sponges. (Note 1) It lays a cream, collar-shaped egg mass
that hatches in five or six days in the laboratory.
Distribution:
Big Island, Maui, Molokai, Oahu, Kauai, Niihau, French Frigate Shoals, Pearl & Hermes Reef, Midway
and
Kure (also Johnston Atoll): widely
distributed
in the Indo-Pacific.
Taxonomic notes:
This
is the species listed as Berthellina
citrina (Ruppell and Leuckart, 1831) in Kay, 1979; Bertsch
and Johnson, 1981; and Hoover 1998. It is listed as Berthellina sp. in Hoover,
2006 (corrected in 5th
printing). It's referred
to as the "orange gumdrop" in
Hoover, 1998 & 2006 as well as in other references. It's listed as Pleurobranchus delicatus Pease, 1861 in Ostergaard, 1955 and Edmondson, 1946. It's possible that Pleuobranchus rufus
Pease, 1860 may have been this species (although Kay, 1979 considers it
unidentifiable) in which case it was first reported from Hawaii in
Pease, 1860.
Photo: CP:
spotted: Napili Bay; Nov. 9, 2003.
Observations and comments:
Note
1: On at least 14 occasions, we've
observed them feeding on the corals Porites
compressa and Porites lobata at night in shallow
back-reef habitats at Hekili Point, Maui. On at least one occasion,
we've seen them feeding on the coral Montipora
capitata. On three occasions, we've
seen them feeding on what appeared to be algal turf although it's
likely that they were eating inconspicuous sponges or other animals
embedded in it. Scott Johnson has also photographed them feeding on the
ahermatypic coral Tubastraea coccinea,
Porites sp., Leptastrea sp. and at least three
species of sponges including Leucetta
solida and Suberites aurantiacus (formerly Terpios zetiki).
(Bertsch
and Johnson, 1981) (see
photos)
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