Northwest Nudibranchs

[Dusty2]

I would say it probably is. The red color is not always readily apparent but if you look close you can see that the rinophores have a redish tint at the tips. There is one other nudi that is very similar and has no red and that is the Acanthodoris hudsoni which this could also be. Tough call, you could argue either case.

[dwashbur]

I'd go with nanaimoensis as well. I don't think it could be a hudsoni because the rhinophores are far too short. One of the characteristics of the hudsoni is the way the rhinophores stick up and curve back a little, almost looking like antlers.

The shape, the plume and the slight reddish tinge strongly suggest you have a very nice Nanaimo there. Good pic!

[karin_f]

Thanks for the help! Nanaimo dorid it is, based on the rhinophore length. Here are a couple of other pictures from the same spot in Rich Passage in Puget Sound that show more variety in the nanaimo form. The one of the "nanaimo gray" definitely shows the maroon tips on the rhinophores. Sorry the one of the three different colored acanthodoris nanaimoensis is so out of focus - I only saw the "normal" one at the time.

Acanthodoris nanaimoensis gray with maroon tips

Acanthodoris nanaimoensis variations

[Dusty2]

Actually the White colored one is a yellow margin dorid. Sorry.

[karin_f]

OK, now I'm confused. My pictures aren't the greatest, but I thought that the difference between an Acanthodoris hudson or nanaimo and a Cadlina luteomarginata (yellow margin dorid) was that the Acanthodoris has pointy papillae

and the Cadlina has stumpy tubercules. Also, what would a yellow margin dorid be doing bumping up against a nanaimo dorid as the two are doing in the photo above?

Cadlina luteomarginata, yes?

[Dusty2]

Well I have been known to make a bad call once in awhile. They are in a classic breeding position so I would assume that they are both the same type although I have been told that crossbreeding does sometimes occur.

I would lean more toward the hudsoni for the middle one and possibly all three. I can't see the rinophores clearly on any of them but the bright yellow margin and the lack of any trace of red on the gill plumbs of any of them would suggest hudson's and they do get that dirty coloration also. It's pretty much a judgment call and if I looked again tomorrow I might go the other way. The two are so similar that the red tips is just about the only identifiable difference without dissection and they do hang out together at times

[karin_f]

Whew - I'm glad that you said that Hudson's can have a gray phase, too - either that, or nanaimos have a phase where they don't have maroon tips. Not being able to see the rhinophores is a big drawback when trying to ID these guys - sorry I posted such a bad photo. I really appreciate your help! Now I know what to pay attention to when taking pictures.

Another mystery is the whole Big Yellow Dorid question...I found this one completely flattened on a rock at Blakely Rock in Puget Sound. It was maybe 3 inches across and SO flat that I thought it was a flat worm, but then saw the rhinophores and withdrawn gills. Its rhinophores look like Peltodoris nobilis, but its gills don't look white; the freckling looks like a Peltodoris lentignosa but I don't think they have black spots.

[Dusty2]

Ah yes, the yellow dorid question. :biggrin: This one is the yellow coloration of the Heath's dorid. If his gills were out they would be white. They also come in white with pink spots, plain white with black flecks and yellow with black flecks and can be flat or rounded (don't ask me why they do it)

Here are a few different ones to confuse you further. These are all Heath's dorids

[dwashbur]

Yep. The biggest tip-off for the Heath's is the flattening that you noticed. They're the only ones that do that. If you see one that looks like it got stepped on but it's clearly still alive, that's most likely what it is.

[karin_f]

Thank you for the ID! Now I know that flattened yellow dorids are Heath's dorids - that's a big help. And thanks for posting other Heath's pictures. I didn't think the one I saw could be a Heath's since it was bigger than the 1.7 inch size mentioned in Lamb & Hanby. Maybe it was bigger because it was flat?

[Dusty2]

Thank you for the ID! Now I know that flattened yellow dorids are Heath's dorids - that's a big help. And thanks for posting other Heath's pictures. I didn't think the one I saw could be a Heath's since it was bigger than the 1.7 inch size mentioned in Lamb & Hanby. Maybe it was bigger because it was flat?

No, They get much larger than that. I'd say more in the 3" + range

[karin_f]

Unusual coloration for the Sandalwood dorid and Hudson's dorid -

Acanthodoris lutea

Acanthodoris hudsoni

[Dusty2]

Interesting. and nice shots.

Allot of the dorids are sporting that dirty black pigment this time of year. I have never seen a brown Hudson's though. Might have something to do with the red seaweed he is living on. That sandal wood has a nice big scale worm on it's back too.

[karin_f]

Interesting. and nice shots.

Allot of the dorids are sporting that dirty black pigment this time of year. I have never seen a brown Hudson's though. Might have something to do with the red seaweed he is living on. That sandal wood has a nice big scale worm on it's back too.

Thanks! The Nanaimo dorids are definitely black right now. The alabaster nudibranch cereta are brown right now, too, which I'm sure is from the brown seaweed as well. But how embarassing I mistook the scale worm for the sandalwood dorid's rhinophore. I wondered why one rhinophore was longer than the other, so thanks for pointing out that it's actually a scale worm! I can't tell you how many times I miss something on a dive that I spot in a photo, but this time I didn't even spot the worm in my own photo

[karin_f]

Dendronotus iris swimming in the shallows at Waterman Wall

[Gooch]

Folks- I wanted to see what this nudi is. It's large, mostly white with faded freckles. I think its the Noble or Freckled sea lemon?
The second is of course a clown nudi but I was happy to see him...my first.

[Dusty2]

Yep, It's a nobel. They come in all sorts of variations. White, yellow and even pink well sorta faded pink anyway.

[Grateful Diver]

Dendronotus iris swimming in the shallows at Waterman Wall

dendronotus iris1c.JPG

Beautiful shot!

... Bob (Grateful Diver)

[mpenders]

Dendronotus iris swimming in the shallows at Waterman Wall

dendronotus iris1c.JPG

We found one of these last night at 3TN swimming along at about 15ft. I got a few fuzzy pics, but nothing as good as yours. Nice shot.

[dphershman]

Lots of Clown Nudibranchs Triopha catalinae at Sunrise Wall this afternoon. Hundreds, for sure! these fellows like high current areas like Sunrise, but these dudes were everywhere!

[Dashrynn]

What is this one?

nudi

This guy is huge!

big nudi

big nudi 2

[dwashbur]

He's a Flabellina verrucosa, one of my favorites.

[Chevayea]

He's a Flabellina verrucosa, one of my favorites.

AKA Red-gilled nudibranch. It always easier for me to remember the common name on 'em.

[Tom Nic]

It always easier for me to remember the common name on 'em.

I know what you mean, and for some nudis that is definitely true. For others.... not so much.

For instance, Flabellina triophina, one of my favorites doesn't have a "common" name that sticks in my head. Or it is different from ID book to ID book and so there isn't a settled name.



Like it or not, sometimes nothing will do but the Latin name if you want to actually get specific about what critter you're actually talking about.

[dphershman]

withdrawn