OKINAWAN
OPISTHOBRANCH OF THE WEEK

Kaloplocamus peludo Vallés & Gosliner, 2006 (17mm)

Opisthobranch of the Week Data

Taxonomy:

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


Species Account:

        Kaloplocamus peludo is considered to be very rare on Okinawa's main island as I have seen and collected a total of three individuals over a period of many years of diving here. In addition to the Okinawa specimens, the species is known from many different localities; Vallés & Gosliner (2006) report it from the Philippines, Papua New Guinea, Palau, Marshall Islands and Tanzania in the Western Indian Ocean. The above featured animal was found following a dive while inspecting material in a sorting bowl later at home. This attractive little polycerid was found on a small fragment of a brown alga blade and was noted to crawl very slowly. Three specimens of Kaloplocamus peludo have been collected here from the same collection site (Seragaki); I've added a second page with images of all three of the collected animals, including images of two paratype specimens.

        The following description of external morphology as well as remarks on the species is taken from Vallés & Gosliner (2006):

External Morphology: The living animal has a general orange coloration (Figure 1D). The whole dorsum has brown dots except at the apices of the lateral appendages, which are pale yellow. These brown dots are similar and [sic] size and regularly distributed. The dorsum has an opaque white, irregularly shaped line, which runs from the front of the head to the posterior end of the notum. This line bifurcates at the level of the branchial leaves, where it surrounds them and remerges again behind the branchial leaves. The posterior end of the foot is thin and acute and has a yellow color similar to that of the lateral appendage apices. Two types of appendages are observed in the specimen. The first type of appendages is the longest and widest. There are three pairs of these lateral appendages situated along the margin of the sides. These appendages have a ramified apex. Each ramification of the apex has a rounded base and a long, thin and sharp prolongation. The whole length of each of these appendages is covered by little and acute ramifications. The second type of appendages, are thin, long with many small sharp, thin and long simple ramifications. These appendages are present on the sides of the body, foot, dorsum and oral veil in number 15-17 per side with 6 on the oral veil. The rhinophores have a lamellate clavus and a peduncule with little, thin and sharp ramifications. Each rhinophoral sheath edge has three ramifications. The middle one is virtually identical to the lateral appendages. The other two ramifications are similar to the smaller tentacles of the rest of the body. The oral tentacles are simple folds of the mantle that have a cylindrical shape. There are three tripinnate branchial leaves. They present long, simple, and thin ramifications as the smaller appendages.

Remarks: This species is characterized by the several features, which make it very different from the other known species of Kaloplocamus. The presence of two kinds of lateral appendages which bear on the apex long, thin and simple filaments; the presence of tubercles with thin and long ramifications as well all over the body; and the particular shape of the rhinophores sheaths disguising themselves as lateral appendages are unique of K. peludo. Even though the general morphology of the radula is typical of the genus Kaloplocamus, several differences are found. The inner lateral teeth have a blunt apex instead of the typical sharp hook shaped. The presence of a granulated rachis characteristic of the genus, differs by not been transversally divided in rachidian plates rows. Other important differences are the absence of rodlets in the jaws and the presence of a distinctive wider prostate gland.

        I've previously featured the following two described species of Kaloplocamus from Okinawan waters:

Etymology:

Literature Cited:


Page Date: 04 Dec '06
Page Modification Date: 04 Dec '06
Digitally manipulated photo
Copyright © 2006 Robert F. Bolland