OKINAWAN
OPISTHOBRANCH OF THE WEEK

Babakina indopacifica Gosliner, et al, 2007 (10mm)
Photo by Atsushi Ono

Opisthobranch of the Week Data

Taxonomy:

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


Species Account:

        As of the current date I've not personally seen specimens of the above newly described Babakina indopacifica here in the waters of Okinawa's main island. Atsushi Ono kindly furnished images and data for the featured animal and he considers the species to be rare in waters of the Keramas* and reports (pers. comm.) seeing and collecting two individuals in the Keramas. Atsushi goes on to say that the above animal was found in a rock environment of a reef. The above image was taken by Atsushi and is used here with his kind permission. I've added an additional image of B. indopacifica, also furnished by Atsushi.

        Nishina Masayoshi (2002) has several images of Babakina indopacifica on the Sea Slug Forum (as Babakina cf. festiva). In addition, Jun Imamoto (2007) has three images of an 8mm animal from the Amami-Ooshima Islands, Japan, as Babakina festiva (Roller 1972), and Rie Nakano (2004, p. 253) has an image of a 15mm animal, as Babakina festiva (Roller 1972).

        The following description of the external morphology of Babakina indopacifica is taken from Gosliner, et al (2007):

The body is elongate and slender, with a trailing posterior end of the foot. Living animals are 7-18 mm in length. The anterior margins of the foot and tentaculiform foot corners are bilabiate and slightly notched. The body colour can range from a translucent light purple to deep reddish purple. A broad opaque white patch covers most of the head between the rhinophores and the anterior margin of the head. A smaller patch may be present just behind the rhinophores in some specimens. In all specimens observed an additional opaque white patch covers the pericardial region. The relatively short cerata are thick, widest in the middle and taper distally. They are almost entirely opaque white with some bluish purple pigment visible on their posterior face. The apex is translucent white. The cerata are densely clustered and continuous throughout the length of the body, without interruption in the pericardial region. The medial area between the rhinophores and pericardial region is relatively devoid of cerata. There are approximately 15-33 diagonal rows of cerata on either side of the body. Each row contains 2-3 cerata with the innermost cerata of each row being the largest. The bright red rhinophores share a common base, are perfoliate and have up to 28-32 lamellae each. The posterior portion of the rhinophores is covered by a fine dusting of opaque white pigment that extends to the apex. The anterior face lacks opaque white and is uniformly red. The oral tentacles are relatively short, but longer than the rhinophores and have a smooth texture. They are pinkish purple basally with a band of opaque white covering the outer one-third to half of the tentacle. The tentacular anterior foot corners are short and are often held close to the body so they are not readily visible. They are pinkish purple throughout their length. The pleuroproctic anus is located ventral to the notal brim about one-third of the body length from the anterior end, ventral to the 14th-16th ceratal row. The nephroproct is anterior to the anus. The genital aperture is located below the notal brim just posterior to the rhinophore base below the seventh ceratal row.

Etymology:

Literature Cited:


        * Keramas = the Kerama Islands Group, located 30 ~ 40 kilometers west of the Okinawa capitol, Naha.


Page Date: 07 Jan '08
Page Modification Date: 07 Jan '08
Digitally manipulated photo
Copyright © 2008 Robert F. Bolland