OKINAWAN
OPISTHOBRANCH OF THE WEEK

Aegires flores Fahey and Gosliner, 2004 (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:

        Aegires floresis considered to be very rare in Okinawan waters; I've not personally seen nor collected any specimens of this attractive little aegirid and it is currently unknown from Okinawa's main Island, but it has been photographed by Atsushi Ono in the Kerama Islands. * The close proximity of the main island of Okinawa to the Kerama Islands, as well as the similar opisthofauna to that of the Kerama Islands, suggests the possibility that it is also present here on Okinawa's main island. The above featured animal is one which was photographed in the waters of Amuro Island by Atsushi Ono during April of 2001, in 5m of water amid coral rubble in the inner portion of a bay. Atsushi's photograph is used here with his kind permission and he considers the species to be very rare in the Kerama Islands, having seen three individuals there (pers. comm.).

        The following description of external morphology and remarks concerning Aegires incusus is taken from Fahey & Gosliner (2004):

        EXTERNAL MORPHOLOGY.-- The body shape is elongate and slightly rounded. The dorsum is completely covered by small raised tubercles, some with flat tops and some with rounded tops. Spicules protrude from the tops of all tubercles. The rhinophore pocket is slightly elevated and is surrounded by approximately five flat-topped tubercles that vary in size. The tubercles on the exterior edge of the rhinophore pocket are large and rounded and look like flower petals. The rhinophores are smooth. The gill pocket lies mid dorsally and is surrounded by approximately twelve flattened, paddle-shaped tubercles in varying sizes, arranged like a crown or an opening flower. The small gill leaves are tripinnate.
        The background color of the living animals is cream. The overlying colors range from gray-white with yellow-topped tubercles to brown with orange-topped tubercles. The paddle-shaped tubercles around the gill can be translucent white with white tips or translucent yellow with darker yellow tips. The rhinophores in all color forms are translucent white as are the gill leaves.
        REMARKS.-- Aegires flores has a unique external morphology. Although it has an elongate body, a rounded posterior end of the foot, a tuberculate notum, protective tubercles around the rhinophores and gill, and smooth rhinophores, there are several unique characters that set this species apart. Most noticeably, the gill appendages have a unique paddle shape. The tubercles on the outside of the rhinophore pockets also resemble those around the gill, both in shape and in color. The dorsal tubercles are all much lower than the protective tubercles, a feature not shared by other Aegires species.
        The reproductive morphology is also different from other Aegires species. The short, wide ampulla with a short deferent duct is a combination of characters not seen in other Aegires species. These features combined with the very short duct leading from the receptaculum to the bursa are not found in other Aegires.
        The unusual combination of external and internal characters distinguishes Aegires flores as a new species.

        I've added a second page with an image of an additional animal from the Keramas which is quite dissimilarly colored from that of the above featured animal. Incidentally, of the three images of Aegires flores in the Fahey and Gosliner (2004) paper, two are quite similar (p. 651, figs. A & C) to the two Keramas animals photographed by Atsushi and featured on these pages. These images from the Fahey and Gosliner (2004) paper are also available on the Sea Slug Forum.

        I've previously featured on these pages the following species of Aegires from Okinawan waters:

Etymology:

Literature Cited:


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


Page Date: 29 Aug '05
Page Modification Date: 01 April '16
Digitally manipulated photo (image has been horizontally flipped)
Copyright © 2016 Robert F. Bolland