Baseodiscus hemprichii (Ehrenberg, 1831) (size not recorded, ca. 100 mm)

Invertebrate of the Week Data


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

Species Account:

        Baseodiscus hemprichii, known as the Striped or Lined Ribbon Worm, is recognized by its whitish to flesh-colored pigmentation having a red or brown line, sometimes very wide, running from the back of the head to the tail end of the body. The line widens at the front, often into a collar, and is sometimes interrupted by regularly spaced spots or transverse bands of a darker color. Some photographs of B. hemprichii show a rather obvious red line but all the Okinawa specimens show only a brown line from head to tail. There are a series of photos found on-line, as well as videos of this remarkable animal. Here are three links:

        Baseodiscus hemprichii is considered to be uncommon in the waters of Okinawa's main island, although I've seen and collected at least nine specimens over many years of Okinawa diving.

        B. hemprichii is the third nemertine added to the site as of the current date. Previous featured animals are:

                Baseodiscus quinquelineatus
                Lineus fuscoviridis

I've added the following information concerning remarks, color, and distribution of B. hemprichii from Kazmi, Q. B. & R. Gibson (1994):


The body is ribbon-shaped; There is a distinct demarcation between the cephalic lobe and the trunk region. The cephalic lobe is small. The dermis and muscular layers are thick. The mouth opens a little way behind anterior end. Several eyes are present in a marginal row on each side of the cephalic lobe.


The general body colour is off-white. A broad scarlet streak extends along the mediandorsal line, a similar coloured but narrower streak running mid-ventrally. At the rear of the cephalic lobe is a transverse scarlet collar of pigment, and a patch is located on the dorsal surface of the cephalic lobe.


Baseodiscus hemprichii is a tropical species, its distribution extending from the Red Sea to the Pacific Ocean. So far it has been reported from Hawaii and Upolu in Polynesia, Wake Island, the Caroline Islands, the Loyalty Islands, New Britain (Solomon Islands), Papua New Guinea, Australia (Great Barrier Reef), Japan, Taiwan, Java, Ambon, the Malay Peninsula, Maldive Islands, Lackshadeew Islands, Coetivity Island (Mauritius), East Africa, India, Pakistan and the Red Sea.


Literature Cited:

        I've added a second page w/ a series of images of the species.

        In addition, I've added a link to the current and past featured invertebrates via a list and thumbnails.

Page Date: 01 Oct '17
Page Modification Date: 01 Apr '18
Digitally manipulated photo
Copyright © 2018 Robert F. Bolland