Aldisa sp. 4 (8mm)
Photo by Atsushi Ono

Opisthobranch of the Week Data


Frequency in Kerama Islands (Okinawa): Collection Data:
[brackets indicate range for all Okinawa-collected specimens of the species]

Species Account:

        Aldisa sp. 4 was photographed by Atsushi Ono during September of 1998 in the waters off Zamami Island, one of a series of islands in the Kerama Islands Group, which are located 30 ~ 40 kilometers west of the Okinawa capitol, Naha. Atsushi discovered the animal in a coral reef environment during a night dive in twenty feet of water. The above image is used with Atsushi's kind permission and he reports (pers. comm.) seeing more than twenty individuals, and he considers the species to be uncommon in the Keramas.

        Aldisa sp. 4 is currently unknown from the waters of Okinawa's main island, but due to the number of animals seen by Atsushi in the Keramas, it's expected to be here as well. There is a similar appearing animal from Taiwan posted on the Sea Slug Forum by Ching-Yao Chan, however this Taiwan specimen has a series of irregular bright white-emarginated yellow spots and the sponge-like dorsal pits normally present on the mantle of these animals isn't apparent.

        I've previously featured on these pages a series of described and unknown Aldisa species. These species are:

  • Aldisa albatrossae
  • A. pikokai
  • A. species 1
  • A. species 2
  • A. species 3
  • A. species 4 (the above featured animal)
  • Literature Cited:

    Page Date: 17 Apr '06
    Page Modification Date: 17 Apr '06
    Digitally manipulated photo
    Copyright © 2006 Robert F. Bolland