young, 4 mm
young, 7 mm
Polybranchia cf. jannae Madrano, Krug, Gosliner, Kumar & Valdes, 2018
|Maximum size: about 64 mm.
leaf-like, tuberculate cerata with serrated edges. The tubercles are
tipped with white and irregular networks
of fine white lines ascend the cerata. The cerata contain small,
granular subapical masses and some have patches of brick-red pigment, irregular black patches and/or diffuse white medial
patches. The marginal serrations contain faintly
iridescent violet to clear spots. The rhinophores are translucent-cream with
golden brown and red patches. Brick-red patches may also be present on
the notum and there may be an opaque-white patch on the pericardium. In mature animals the irregular black
patches on the cerata may become more numerous, the white lines on the cerata may be lost and
numerous purple spots may develop (particularly along the edges of the cerata). The rhinophores are slender and the
foot, at least in mature animals, ends in a long "tail" filament.
Polybranchia cf. jannae
is known from four animals. The 7 mm juvenile was found crawling on
sand-saturated algal turf
during the day at a depth of 4 m (12 ft) at a moderately exposed site.
The 4 mm juvenile was found in an algae wash taken at about 16 m (53
ft). The large, mature animal was found in an aquaculture tank on the Big
Island in association with Caulerpa lentillifera. The animal without red patches was found at a depth of 1-3 m (3-7 ft) at a moderately protected site. It may feed on Caulerpa lentillifera (and relatives?).
Big Island and Maui: may be known from the western Pacific.
Taxonomic notes: This species is similar to some animals assigned to Polybranchia jannae
from the western Pacific. However, the match is imperfect so we're
treating the ID as tentative pending more material. Similar animals from elsewhere can be seen at Lazy Diving and Sea Slug World. It was first recorded in
Hawaii from Hekili Point, Maui by CP on March 29, 2014.
Photo: Pam Madden: side; about 64 mm: found by Sarah Milisen on Caulerpa lentillifera in sea tank at NELHA, Kona, Big Island; Jan. 11, 2022.
Observations and comments:
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