OKINAWAN
OPISTHOBRANCH OF THE WEEK

Pruvotfolia rhodopos (Yonow, 2000) 25mm
Photo by Shawn Miller

Opisthobranch of the Week Data

Taxonomy:

Frequency on Okinawa: Collection Data:
[brackets indicate range for all Okinawa-collected specimens of the species]


Species Account:

        Pruvotfolia rhodopos is considered to be very rare in the waters of Okinawa's main island. I've never personally seen this animal here and the photographer, Shawn Miller, mentions the above featured animal is only one of two individuals he's seen (the second from the same site and date). Shawn found the two animals on a live coral reef during a night dive and his images are used here with his kind permission. I've also added a second page with an additional image of Shawn's animal.

        The following description and remarks concerning Pruvotfolia rhodopos are taken from Yonow's 2000 publication*:

        Description: This delicate species has been photographed several times in the Red Sea. The body colour of living specimens varied from yellow to pale orange, but was translucent. The body was moderately narrow but the foot was very wide. The cerata were distinctive, usually club-shaped with a terminal nipple, but sometimes fusiform. They were translucent, with an opaque peach or pink ring which was sharply demarcated below but diffuse above, presenting a coloured band distally on the cerata. The tip itself was always white. The reddish brown digestive gland was visible as a central extension only, with no ramifications. There were seven or eight clusters of cerata with a large gap and a swollen pericardium between the first two. I am unable to distinguish arches or rows on the preserved specimens; from the photographs, there were six to fifteen cerata per cluster. Under or amongst the first cluster, the genital swelling can be seen on most of the photographs. The pale to bright orange rhinophores were obliquely lamellated. They were slightly longer than the large propodial tentacles but one third the length of the oral tentacles. The tips of the tentacles may be white. The head and cardiac region were brighter in colour and the eyes were visible at the base of the rhinophores. The jaws were visible at the sides of the head in the photographs and in the preserved material. The foot was broad and much longer than the body: this length was marked by a central longitudinal peach or pink band, part of which remains in the preserved specimens.
        Both specimens have the gonopore swollen in an identical manner, coiled but attached at the centre; the penis was not obvious. This swelling is also visible in the photographs. Ventrally the foot is bilaminate and the mouth is covered by a small flap extending from the top of the foot.

        Remarks: The species is clearly distinctive in its colour pattern of opaque pink to peach rings on the cerata and the longitudinal coloured marking on the metapodium. However, generic placement is more difficult. Recent literature has concentrated on the family Flabellinidae and the subfamily Favorininae (belonging either to the family Facelinidae or Glaucidae, depending upon school of thought), and the higher systematics of the remaining subfamilies are desperately in need of revision.

        There are a series of photographs of Pruvotfolia rhodopos on Scott and Jeanette Johnson's Kwajalein Underwater site (http://www.underwaterkwaj.com/index.html) with several of the photos showing animals on egg masses.

        *Pruvotfolia rhodopos was originally described by Yonow (2000) as Facelina rhodopos but is now considered to be Pruvotfolia rhodopos. There is some disagreement about the generic placement of this facelinid but Gosliner et al (2008) state that Pruvotfolia rhodopos has the cerata specialized for copulation as found in Pruvotfolia.

Etymology:

Literature Cited:


Page Date: 01 Nov '13
Page Modification Date: 01 Nov '13
Digitally manipulated photo
Copyright © 2013 Robert F. Bolland