Hallaxa fuscescens

Image courtesy of Jim Anderson
Photo location: Villa Markisa Resort, Bali, Indonesia
Photo taken with Sony a6000 with Zeiss 50 mm macro lens in Nauticam housing with a CMC-1
dioptre in flip holder; 2 x D2000 Inon flash guns on manual and a Sola 1200 spotting light

Hallaxa fuscescens (Pease, 1871)

Well this is a new one for me. It was originally described from the Society Islands. Its body is translucent with low rounded black tubercles scattered over the mantle. The gills are bipinnate and arranged in a tight, upright circle around the anal papillae. This gill is very diagnostic because of its goblet-shape which is so characteristic of this family. Noting Bill Rudman's Forum we see that the species is wide spread throughout the western Pacific. Hallaxa fuscescens feeds on a species of the 'slime sponge' Halisarca. The sponges name because they are often form denotes that it is a thin smooth slimy film over the rock on which they are attached. This species of sponge often goes unnoticed.

WEBMASTER'S NOTES: Dave and I would like to thank Rie Nakano of Japan who made this identification possible!

Dave Behrens
Sammamish, WA 98074
Oct., 2017
Send Dave email at davidwbehrens@gmail.com


An architect who retired from practice in 2011, Jim Anderson is fascinated by the incredibly colourful world that lies just a short distance from the shore around the coast of his home in Scotland. He learned to dive there and very quickly discovered the diversity and extravagance of life that the grey sea does well to disguise. Photography started as a means of recording these sights - to try in some way to let others into this wonderful new world that was opening up.

He commenced diving in 1987 and has recorded over 4000 dives, over 2200 around Scotland, mostly with a camera in hand and has developed special skills in capturing images that have been widely published in national diving publications and identification guides. He is the proprietor of nudibranch.org the portal to his extensive nudibranch and other web sites covering his home country and the destinations he has visited in the Philippines, Indonesia, Maldives, Red Sea, Kenya, Ireland and in the Caribbean. He is a 1st Class Examiner with the Scottish Sub Aqua Club and delivers Nudibranch Identification courses on behalf of the UK Marine Conservation Society."

Send Jim mail at jander4454@gmail.com

WEBMASTER'S NOTES: Jim is being rather modest about the rigors of diving for sea slugs in his home waters. Although not mentioned the reader can be assured that getting geared up in the waters off Scotland is a challenge in itself! Our hats are off to you Jim!



From left to right, Terry Gosliner, Angel Valdes, Dave Behrens La Jolla, Calif.

Send Dave email at davidwbehrens@gmail.com

© The Slug Site, Michael D. Miller 2017. All Rights Reserved.