young, 4 mm
Polybranchia jensenae Madrano, Krug, Gosliner, Kumar & Valdes, 2018
|Maximum size: 90 mm.
leaf-like cerata with serrated edges and rounded tips. The outer face
of each ceras is evenly papillate while the inner face has longitudinal
veins that become more prominent in larger animals. Irregular networks
of white flecks cover the cerata and their bases are cloudy. The
pericardium is translucent-gray. Young
animals may have one or more enlarged papillae in the middle of the
inner face of each ceras. A few brick-red highlights may be present in some juveniles.
is a moderately common species found at depths of < 1-8 m (< 3-26 ft). It occurs in highly protected to
moderately exposed rocky habitats. It's nocturnal but can be found
under rocks during the day. When disturbed, it can autotomize its
central cerata. However, it does so much less readily than Polybranchia samanthae. Medrano, et. al. (2018) reports observing Hawaiian animals feeding on Caulerpa racemosa when held in dishes.
Maui, Oahu, Kauai and Midway: widely distributed in the Indo-Pacific.
Taxonomic notes: Members of this genus were first described from Hawaii by Pease in 1860 under the name Polybranchia pellucida. Later, Kay (1979) used the name Branchophyllum
pellucida. However, Medrano, et. al.
(2018) states that their descriptions are insufficient to distinguish
between Polybranchia jensenae and P. samanthae.
So, one or both were probably first reported from Hawaii in
1860 or Kay, 1979. One or the other may also have been the animal
referenced in the text at the bottom of page 185 in Edmondson, 1946.
Photo: CP: 35 mm; few cerata autotomized: Hekili Point, Maui; Oct. 21, 2007.
Observations and comments: