Saturday, March 25, 2006

Cool photo of the day. Diane spotted this Flabellina just as it was starting to lay eggs.

Nembrotha lineolata on the Forum

Nembrotha lineolata with its head inside an ascidian. According to Bill Rudman at the Sea Slug Forum, solitary ascidians like this, often known as 'sea squirts', have an outer sac which protects the delicate sieve-like basket which filters their food out of the sea water and encloses the rest of the body. It looks like species of Nembrotha feed on solitary ascidians by inserting their extensible oral tube through one of the siphons to get to the fleshier parts of the body.

Kate found this amazing little nudi today at 17 meters. (4-5mm)

The Measurement.

Sea Spider. Nymphon sp.


Allied Cowery. Eggs on the left?

Wednesday, March 15, 2006

Tuesday Night at Sandy Bottom

Diane and I got a bit of a shock last night at Sandy Bottom. Hanging out at about 15M, and just a few meters away from us, was a very large Manta Ray. I'm not sure how big he was, but he was bigger than Diane. Sorry, my heart was beating too hard to take a photo as he soared away from us.

Mystery of the night. It's not the shrimp, but the white and yellow disk just to the right. This animal was found moving up and down the arms of the crinoid. Anybody know what it is???

Check out all the fuzzy 'wiskers' on this sole. 4cm.

I think I have a new fascination with brittle stars. They are really amazing and beautiful creatures.

Tuesday, March 14, 2006

Lendell and I went back out to Bob's Rock on Monday afternoon and Lendell spotted the same Phyllodesmium longicirrum that Diane found on Sunday.



Ribbon Eel

Sunday, March 12, 2006

Birthday Dive at Bob's Rock

Phyllodesmium longicirrum, 16cm. Diane came through once again, finding this fantastic nudibranch at 18 meters. It had just eaten a small leather coral and was moving on to find it's next conquest.

And on the other extreme, Lendell spotted this little Chromodoris fidelis, 2cm

Two perfect birthday presents.

Wednesday, March 08, 2006

Tuesday, March 07, 2006

Halgerdas at Dili Rock.

Nice definition of the sex organs.

They are a bit difficult to visually separate, but this photo is of two brittlestars. The smaller one in front has a perfect little star on it's body.

Sunday, March 05, 2006

After the Storm

The cyclone has finally passed without much trouble, leaving a clear, sunny Sunday. But it also left Sandy Bottom scoured by surge and strong currents. The bottom now has a layer of fine sediment a few inches deep. But we have seen this before at Sandy Bottom. Life will return quickly with new soft corals making their way up through the silt and sand. In a week or so, it should be back to normal. Who knows, the storm may have brought in a few new species just waiting to be discovered.

Beautiful White Pipehorse

Usually we see these pipehorses on the sandy bottom and the lack of contrast result in washed-out photos. This individual was found clinging to a stem atop a dull red leaf.


Still have to figure this little guy out. 1cm

Saturday, March 04, 2006

Inspiration for diving. The cyclone that has hampered our chances of diving in the last week has finally passed. Cyclone bad. Sunshine good. Let's dive.

Friday, March 03, 2006

Could this be a Spanish Dancer?
March 3, 2006 From: Brian Francisco

Hi Bill:

Is it possible that these photos are of a juvenille Spanish Dancer Hexabranchus sanguineus. This individual was quite small, about 12 mm, and I'm not sure I can count 6 gills.

Locality: Beach, 7 meters, East Timor, Banda Sea, 26 February 2006, Sandy Bottom. Length: 12mm. Photographer: Brian Francisco.

Thanks very much
Brian Francisco

Francisco, B., 2006 (Mar 3) Could this be a Spanish Dancer?. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from

Dear Brian,

Yes this is indeed a juvenile Hexabranchus. Good call! The gills in juveniles are quite interesting. The dorid nudibranchs are divided into two large groups depending on whether their gills can retract into a protective pocket Cryptobranchia or Eudoridoidea or do not have such a pocket Phanerobranchia or Anadoridoidea. Obviously in adults, Hexabranchus has no sign of a gill pocket and each gill is separately inserted into the skin. It would seem to be clearly a phanerobranch. However phanerobranchs are usually the elongate forms, such as the nembrothids, while the large flat dorids with wide mantle skirts are usually cryptobranchs, with a gill pocket. Cryptobranchs are also sponge feeders, like Hexabranchus, while the phanerobranchs are all specialised feeders on a wide variety of invertebrates. There are of course other anatomical differences.

However if you look at juvenile Hexabranchus, you can see there seems to be a ridge around the gills and the tissue inside that is translucent, without the colour pattern of the rest of the mantle. I wouldn't be surprised if that is all that is left of a gill pocket, which has been lost in the evolution of this species, but is still indicated in juveniles. Does that make Hexabranchus a very special cryptobranch, or does it suggests that it is a link between the two groups, indicating that the phanerobranchs evolved from the cryptobranchs? I wouldn't like to this stage, but it is certainly something that students of phylogeny should consider. I'm glad you picture shows it so clearly. In living animals they gills can almost completely disappear.

Best wishes, Bill Rudman

Rudman, W.B., 2006 (Mar 3). Comment on Could this be a Spanish Dancer? by Brian Francisco. [Message in] Sea Slug Forum. Australian Museum, Sydney. Available from