Phyllodesmium poindimiei (Risbec, 1928)
|Maximum size: about 50 mm.
species has a very slender, elongate body with cerata
that are cylindrical, smooth and curved at the tips. The digestive
gland ducts extend to the very apex of each ceras and have simple
branches. Each duct and its branches is typically orange at the base,
becoming yellow near the tip. There is usually a blue iridescence
subapically on the cerata, rhinophores and cephalic tentacles. The
rhinophores are long, smooth and roughly equal in length to the
is moderately common on its host octocoral, Carijoa sp., where it is extremely
well camouflaged. It has been found in moderately protected, shaded
habitats from 6-20 m (20-65 ft). It's primarily nocturnal, concealing
itself near the bases of the octocoral during the day and crawling out
to the tips of the plumes at night. Since its food octocoral is known
to be an introduced species, it is also probably introduced. (Note 1) It autotomizes its cerata readily. (Note 2) Wagner, et. al. (2009) reported that it
lays a white spiral egg mass that hatches in 5-6 days in the laboratory
and that it is preyed on by the swimming crab Thalamita integra.
Big Island, Maui and Oahu: widely distributed in the Indo-Pacific.
the municipality Poindimie in New Caledonia from which it
was originally described, it was first recorded in Hawaii from Mala
Wharf, Maui by CP on Oct. 15, 1995.
about 40 mm: near Carijoa
sp.; St. Anthony wreck, Maui; May 20, 2011.
Observations and comments:
1: The octocoral Carijoa sp. is one of almost 300
non-native marine invertebrates known to have colonized Hawaii and is
considered one of the most invasive. It has spread rapidly during
the 35 or more years since its introduction and is now considered a
threat to black corals and their symbionts as well as to Hawaii’s
precious coral industry. Phyllodesmium
is one of its few known predators.
Note 2: In one
case, autotomized cerata continued to move for over three hours after
they were dropped. Perhaps, this serves to distract potential predators?