Crab ID

dwashbur · Post by **dwashbur** » Mon Jan 21, 2008 12:46 pm

Yeah, I know, it ain't exactly northwest at the moment, but northwest folks are just so much more helpful than California folks :smt038 Anyway, the biggest problem in identifying this guy is all the little anemones here and there in key places. He was in about 30 fsw, in the rocks along the Monterey breakwater, and his carapace is about 6" across. I confess that even with Greg's book, we're stumped.

dwashbur · Post by **dwashbur** » Tue Jan 22, 2008 12:40 pm

Hmm, nothing... I'm gonna guess either nobody knows, and/or Greg's not on this list or hasn't been on in a day or so...

John Rawlings · Post by **John Rawlings** » Tue Jan 22, 2008 12:52 pm

dwashbur wrote:Hmm, nothing... I'm gonna guess either nobody knows, and/or Greg's not on this list or hasn't been on in a day or so...

"Oh, ye of little faith!"

Greg's a member here....probably just hasn't been here for a few days. We're all waiting to see what he says on this one!

- John

dwashbur · Post by **dwashbur** » Tue Jan 22, 2008 5:42 pm

John Rawlings wrote:
dwashbur wrote:Hmm, nothing... I'm gonna guess either nobody knows, and/or Greg's not on this list or hasn't been on in a day or so...
"Oh, ye of little faith!"

Greg's a member here....probably just hasn't been here for a few days. We're all waiting to see what he says on this one!

- John

1. I'm new.
2. I'm dumb enough to open my yap

3. I make no apologies for being so dumb 'cuz I was born that way ;-)
4. Thanks for the info. I'll await Greg's expertise!

John Rawlings · Post by **John Rawlings** » Tue Jan 22, 2008 6:09 pm

Hee Hee Hee.....while we wait for Greg, I'll give it my "best guess" -

I wonder if it might not be a Moss crab, Loxorhynchus crispatus.

To the best of my knowledge, I have never seen this crab, but the legs appear to be correct for this species based on what I see in the photo in Pacific Coast Crabs and Shrimps . Further, the description says that the carapace has several "large, blunt tubercles", which I seem to see in your photo.

Another portion of the description in Greg's book seems to fit with the photo as well: "Decorates heavily with algae, bryozoans, sponges, and other invertebrates."

However, he states that the maximum carapace size is 4.8 inches for males....how confident are you in your estimate of 6 inches?

- John

nwscubamom · Post by **nwscubamom** » Tue Jan 22, 2008 6:34 pm

<raises>

I know this one! Pick me! Pick me!!

It's a Masking Crab (Loxorhynchus crispatus - same species John picked!) and those suckers look like something out of a horror movie to me when you're used to our meek mild Kelp crabs that we have around here. It uses other critters attached to its shell to MASK its appearance...get a load of all the little anemones growing on this guy!

Freaked me out when I saw them - and I was on a night dive on the Monterey breakwater when they were out and moving. CREEPY!!!

REEF monitors for these dudes in California.

- Janna

dwashbur · Post by **dwashbur** » Tue Jan 22, 2008 11:26 pm

Cool! We were playing with another one today, and those claws are humongous! They look like vise grips. The one today wasn't decorated, but I see in Greg's description that when they mature they stop playing dress-up. It all fits. Thanks, all! $\:D/$

nwscubamom · Post by **nwscubamom** » Wed Jan 23, 2008 7:55 am

There is another very similar looking crab called the Sheep Crab (Loxorhynchus grandis) which is bigger, and non-decorated. REEF monitors the Sheep and the Masking crab together in the same grouping because they're a bit hard to tell apart I guess.

So maybe that's what you're seeing.

- Janna

dwashbur · Post by **dwashbur** » Wed Jan 23, 2008 9:38 am

Yes, Greg's book seems to indicate that the biggest difference between them is the sheep crab's rostrum has a distinctive downturn. Trouble with the one we were playing with yesterday is, nobody noticed his rostrum - we were all focused on the gigantic claws and keeping them from taking hold of us - and we didn't get any good pictures of it, either. Oh well.

Greg Jensen · Post by **Greg Jensen** » Wed Jan 23, 2008 9:58 am

Definitely a Loxorhynchus. Surface of the carapace looks like L. crispatus, but there appear to be some spines along the edge which are present only in grandis. Or it could just appear that way due to decorations.
You may find crispatus up here in our area. Since my book came out, they have turned up in Oregon, around Cape Flattery in WA, and up in Tahsis inlet on Vancouver Island.

nwscubamom · Post by **nwscubamom** » Wed Jan 23, 2008 10:38 am

OOH, very cool!! Tahsis!! I'll keep my eye out for these guys when I go up there in a few months.

- Janna

John Rawlings · Post by **John Rawlings** » Wed Jan 23, 2008 10:41 am

Greg Jensen wrote: You may find crispatus up here in our area. Since my book came out, they have turned up in Oregon, around Cape Flattery in WA, and up in Tahsis inlet on Vancouver Island.

Tahsis???? Yet ANOTHER reason for me to get back up there....an exciting search for the elusive Loxorhynchus crispatus! $\:D/$

- John