A crabby ID question from California

[aviddiver.her]

I photographed these two crabs in Monterey, CA in shallow water on a Wharf. Can anyone help me confirm their ID?

[nwscubamom]

The 2nd one looks like a Sharpnosed crab to me. Legs are too chunky to be an Oregonia gracilis.

Also, in the first photo, your hermit crab is sitting amidst Invasive Bryozoan!! (Watersipora subtorquata) What wharf were you at?

Oh - and welcome to the forum!! We were just down in Monterey at the end of May.

- Janna

[aviddiver.her]

Wharf II has Watersipora subtorquata all over the place. I didn't realize it was considered invasive.

We were in Monterey May 15-18.

[Chenari]

I believe the Hermit is a Maroon Hermit. From my personal experience, I've seen them to be pretty common in the Monterey area. Still a nice find. :smt038

[Greg Jensen]

Yep, it's a maroon hermit (Pagurus hemphilli), and the other appears to be a Scyra. Reddish color of the eye is unusual though.

[aviddiver.her]

Thanks. Looks like I've got a pretty good consensus confirming my first thoughts. I'll label the first one Maroon hermit (Pagurus hemphilli) and the second Sharp-nosed Crab (Scyra acutifrons). Thanks!

[coachrenz]

Thanks. Looks like I've got a pretty good consensus confirming my first thoughts. I'll label the first one Maroon hermit (Pagurus hemphilli) and the second Sharp-nosed Crab (Scyra acutifrons). Thanks!

If Greg says that is what they are, that is what they are. If you didn't recognize the name, Greg is the Greg Jensen, author of Pacific Coast Crabs and Shrimps which is the book for crabs and shrimp.

[Leslie]

We've got 3 species of Watersipora in California - W. arcuata (an eastern Pacific native), W. subtorquata (invasive), and another species that's undescribed (also thought to be invasive). Subtorquata & arcuata can be distinguished by the shape of the aperture of the individual zooids while the new species is morphologically identical to subtorquata.

[aviddiver.her]

Thanks. Looks like I've got a pretty good consensus confirming my first thoughts. I'll label the first one Maroon hermit (Pagurus hemphilli) and the second Sharp-nosed Crab (Scyra acutifrons). Thanks!

If Greg says that is what they are, that is what they are. If you didn't recognize the name, Greg is the Greg Jensen, author of Pacific Coast Crabs and Shrimps which is the book for crabs and shrimp.

Thanks Tim,
Yes, I recognized Greg's name. I'm new here so I understand why you might wonder. Sorry my wording made it sound as though I thought the ID was uncertain (though Greg did not sound 100% certain on the Scyra). Both Janna and Chenari ID'd the crabs correctly as well. I didn't want to discount the other correct opinions given by so I called it a consensus rather than giving all of the credit to Greg.

[aviddiver.her]

We've got 3 species of Watersipora in California - W. arcuata (an eastern Pacific native), W. subtorquata (invasive), and another species that's undescribed (also thought to be invasive). Subtorquata & arcuata can be distinguished by the shape of the aperture of the individual zooids while the new species is morphologically identical to subtorquata.

So Leslie, are you suggesting that his Watersipora may be arcuata and therefore not invasive? Or just that this may not be subtorquata but still invasive?

[Leslie]

The short answer is that I don't know, Nancy. It takes an extreme macro shot to show the apertures but here's what they look like for arcuata & subtorquata:
http://www.bryozoa.net/cheilostomata/wa ... ipora.html
Apertures in the new species look like those of subtorquata.

Between my first reply & now I did a little research on distribution. W. arcuata is more of a warm water species that's found south of Santa Barbara, CA. The undescribed new species has been confirmed for areas between Port Hueneme & Humboldt Bay so it could occur in Monterey Bay. W. subtorquata is very abundant in some areas of Callifornia but some bays & harbors only have the new species. Lamb & Hanby's book reports Watersipora cucullata which is an older name for Watersipora subovoidea, a tropical species. I guess Oregon & Washington specimens need to be checked to see if they're really subtorquata or the new species but that will take DNA analysis.

My info came from a report to the California Department of Fish & Game (which explains the focus on California occurrences): Geller, J., etal. 2008. Distribution of highly invasive bryozoans belonging to a cryptic species complex in the genus Watersipora determined by DNA sequences. Report to CDFG, 40 pp.