Favorinus sp. #1
|Maximum size: 14 mm.
This species is very similar to Favorinus japonicus
with two to three swellings on its rhinophores. The cerata vary from
white to brown and they usually have violet subapical spots. (Note 1) The
surfaces of the cerata are nodular but the nodules are usually less prominent than in F. japonicus. In addition, they usually have finer white flecking than in that species.
Favorinus sp. #1 is a moderately
common species found in moderately exposed to exposed rocky habitats
and Halimeda kanaloana beds
at depths of 4-9 m (13-30 ft). Like F.
japonicus, it feeds on
the eggs of other opisthobranchs. (Note 2) It lays a
white, spiral egg mass composed of a narrow ribbon that hatches in
four days in the laboratory.
Maui, Oahu, Kauai and Midway.
There is some possibility that this species may turn out to be a color
form of F. japonicus. It was
first recorded in Hawaii from Airport Beach, Maui by CP on Sept 12,
Photo: CP: 5 mm: found by PF; Whaler's Village, Maui; April 22, 2007.
Observations and comments:
The violet pigment appears to be deposited in the tip of the digestive
gland and to be independent of pigments in the egg masses that they're
We observed one feeding on a cephalaspidean egg mass that was laid in a
holding dish. Photos include feeding on aplysiid masses.