Please help ID this crab

Fish & Invertebrate sightings and descriptions, hosted by resident NWDC ID expert Janna Nichols (nwscubamom).
Post Reply
User avatar
aviddiver.her
Frequent Bubbler
Posts: 38
Joined: Tue Jun 09, 2009 10:18 pm

Please help ID this crab

Post by aviddiver.her » Sun Oct 11, 2009 11:13 pm

I don't think I've ever seen this one before. The only crab ID book I have is Gotshall and it doesn't have anything with a carapace that is segmented like this. (I'm waiting for Christmas to get my Jensen Crab and Shrimp ID book). I took this in Northern California at Russian Gulch State Park in Mendocino county.
Attachments
N2009.10.11-26.jpg
Here is a WA of it in it's environment.
N2009.10.11-26-2.jpg
Here it is cropped in closer.

User avatar
John Rawlings
I've Got Gills
Posts: 5781
Joined: Sat Feb 25, 2006 8:00 am

Re: Please help ID this crab

Post by John Rawlings » Mon Oct 12, 2009 6:04 am

:uh: Looks like it's both dead and upside down to me. The carapace isn't visible.
“Don’t pick a fight with an old man. If he is too old to fight, he’ll just kill you.”

Image

http://www.advanceddivermagazine.com
http://johnrawlings.smugmug.com/

User avatar
aviddiver.her
Frequent Bubbler
Posts: 38
Joined: Tue Jun 09, 2009 10:18 pm

Re: Please help ID this crab

Post by aviddiver.her » Mon Oct 12, 2009 10:16 am

Well now, upside down would explain a lot of things :biggrin: . Like why the "carapace" is segmented, and why it's claws are on the bottom and why it let me take so many photos without it running away. But then, when it didn't run off I considered if it might be dead and saw it moving it's claws and legs so decided it was alive. We had very little surge but I suppose it is possible the surge moved the legs and fooled me #-o but I don't know :dontknow: . If you look at this other image it does not have that bit of white "stick" running from it's little claw to the main body like it did in the first one. I'm not sure if it is actually holding that thing in the first or if it is an optical allusion. Also, when I look at all of the photos and lighten them up I can't see any evidence of a carapace underneath in the shadows. Of course, if it is dead it may not have a carapice.
Attachments
N2009.10.11-19.second.jpg

Scott G
Aquaphile
Posts: 109
Joined: Fri May 11, 2007 5:56 pm

Re: Please help ID this crab

Post by Scott G » Mon Oct 12, 2009 5:32 pm

its probably an upside down pacific rock crab- cancer antenarrius... maybe cancer branneri...

User avatar
Greg Jensen
Amphibian
Posts: 841
Joined: Thu Nov 15, 2007 9:02 am

Re: Please help ID this crab

Post by Greg Jensen » Tue Oct 13, 2009 9:53 am

It's a Cancer antennarius- the red spotting on the underside is a distinctive feature. Could just be a molt flopping in the 'breeze', with the carapace missing.

Post Reply