wordless Wednesday

Pacific sand crab ~ 11/25/13 ~ Asilomar Beach

Pacific mole crab / Pacific sand crab

Emerita analoga

They look like delicately patterned cracked egg shells. At first, I didn't think these pics were ideal as an ID entry, but it occurred to me that I tend to see the carapaces of sand crabs more often than actual live crabs, which has been late at night while looking for grunion.  Are they nocturnal?  I'm assuming the numerous carapaces are from a mass molt, rather than a mass die-off of sand crabs, but I don't really know. I'm always amazed how the composition of wrack changes through the seasons. Here's a mixture of sand crab carapaces, various red seaweeds, and surf-grass. It's nature's compost by the sea.

ps - In the first photo, directly behind the right carapace, the out-of-focus green surf-grass is covered in pink-colored crusting red algae called Melobesia mediocrus.

cancer crabs ~ 11/03/11 ~ Morro Strand Beach

rock crab carapaces
Cancer spp.

The interior of Cancer carapaces are amazingly colorful. These almost look like they've been filled with Easter egg dye and sand.

This post was very challenging to research, hence it's link-laden. According to the California Department of Fish and Game, we have 9 species of Cancer crabs. I used an old edition of Light's Manual: Intertidal Invertebrates of the Central California Coast sent to me by Steve at Blue Jay Barrens (Thanks again, Steve!), which listed only 8 species and keyed 6 of those.

I'm attempting to ID based solely on the carapaces, which is the most common body part I saw washed up on the beach. Everything I found were 1-3" in width. Since crabs molt, size is not a significant indicator of a species. I spent quite a bit of time zooming in on each of the photos and counting the carapace spines/teeth. There is very little information online for some of the smaller species. If you're curious to learn more, make sure to click on the embedded links under each photo.

Dungeness crab
Cancer magister (aka Metacarcinus magister)
for more information click here and here

slender crab / graceful rock crab
Cancer gracilis (aka Metacarcinus gracilis)

best guess yellow rock crab
best guess Cancer anthonyi (aka Metacarcinus anthonyi)

best guess hairy rock crab
best guess Cancer jordani (aka Romaleon jordani)

While I may have linked to these above, here, by name, are the best photographic crab ID sites I've found for the west coast of North America:
Crab Identification @ Oregon Department of Fish and Wildlife
Key to Family Cancridae--Cancer Crabs @ Walla Walla University
Intertidal Invertebrates of the Monterey Bay Area @ University of California, Santa Cruz
Rocky Shore Crustaceans @ Seanet, Stanford University (also check out Subtidal Crustaceans)

Crustacea of Southern California @ University of California, Irvine

Odd thing about me, whenever I see a crab, I always get a sudden hunkering to eat them with lots of butter. I'm not kidding. Here are other links that caught my interest:
Baby Crab Eater @ The Drop-In to Moss Landing Marine Labs blog
Crabfest 2011 @ The Monkeyface News blog
California Fisheries Atlas - Rock Crabs @ California Fisheries Fund
Don't Hang Up Those Hoop Nets Just Yet - Crab Season is Year Round @ Western Outdoors News

ps - For a little bit of gutter humor, as I was researching the IDs above using the old Light's Manual and with selective choice of spp. and words... I discovered pee crabs, er, pea crabs (Pinnixa spp. and others) live in penis fish (Urechis spp.) burrows. Haha, who knew!?!

blueband hermit crab ~ 10/02/11 ~ Shoreline Park

blueband hermit crab

Pagurus samuelis

This is the first time I've really looked up hermit crabs. It's a challenge to find local hermit crab information, because most searches show pet hermit crabs from the Caribbean and Ecuador. I've collected better marine internet sources since my first hermit crab post on 06/04/09.

The blue bands on the legs, solid red antennae, location, and behavior make me fairly confident of this ID. We have a variety of hermit crabs here, including grainyhand hermit crab (Pagurus granosimanus), bering hermit crab (Pagurus beringanus), and hairy hermit crab (Pagurus hirsutiusculus).

Thanks to a nifty new interpretive sign, I learned the black shells with sanded tops and edges were made by black turban snails (Chlorosroma funebralis). There are a couple different snail shells being used by hermit crabs in the last picture. My wild guesses are possible Littorna sp. or Nucella sp. Stanford's SeaNet also has a nice representation of other subtidal shelled gastropods. And, I really like Gary McDonald's UC Santa Cruz's Intertidal Invertebrates of the Monterey Bay Area, CA site.

Make sure to click on any of the highlighted words (embedded links) for more information.

grunion greeting, 2011 #1

grunion greeting
new moon, 10:20-11:25, clear skies

Yep, it's that time of year again - grunion greeting... er, no greeting as the case may be for Andy and me. I can't believe this will be our third year participating in this Pepperdine University study. For those who are not familiar, there are small silvery green ocean fish called grunion (Leuresthes tenuis) that spawn on California beaches during high tides, sometimes in massive numbers. The highest tides occur at night around the new and full moon and are the best times to spot grunion runs. Monterey Bay and San Francisco Bay are the northern limits of where grunion have been reported. We've only seen them a handful of times, like on June 7, 2009, May 25, 2009, and May 24, 2009. Folks in warmer southern California can regularly see massive runs during the spring and summer months. My favorite disco video of grunion I've found is on YouTube.

I previously incorrectly named our standard grunion beach as Del Monte Beach. Since the spring of 2009 when I was figuring out a name for this location, both google and mapquest maps have changed. This is the beach that is closest to the commercial wharf, aka Wharf 2, and I often refer to it as "the pier" in grunion greeting posts as shown in the first photo above. I think technically this beach belongs to the City of Monterey and may not be included in the expansive Monterey State Beach. I don't know who's in charge of drawing lines in the sand.

As for the second picture above, that was a plane with all its lights on coming in for a landing at our local airport. Impromptu sky art. Hey, gotta do something when the grunion don't show for their own party.

Finally, the last picture is of mating Pacific sand crabs, aka Pacific mole crabs (Emerita analoga). We saw hundreds of them in about the same place that we've seen grunion. Interesting to note, for all the times we've been out on the beach at night looking for grunion, the only other time we saw sand crabs was the 2010 June new moon.

grunion greeting, 2010 #6

grunion greeting
full moon cycle, 10:35-12:30, overcast skies

Yeah, I know, I said we weren't going to do this again... but Dr. Martin let us know she was going to be in town and checking a couple beaches along Monterey Bay. I didn't commit to going out. It's been an extremely busy several weeks for us, and yet we wanted to see grunion this year.

We did. Count em'... 2. I'm okay with that.

Andy and I stood by our usual spot, while our cohorts walked down the beach. Karen called us over. Diane and her friend are reporting 30. I was playing with Karen's night scope (very cool toy) and didn't take any pictures of grunion for this blog. Here's a picture from last year that about sums up our experience of volunteering.

However, I did get a much better photo of that crab we saw last year on June 8. I've been looking for an ID and have been unsuccessful. I believe it is a type of shore crab. Can you ID?

ps 10/07/10 - While searching through Stanford's Hopkins Marine SeaNet site, I came upon the graceful rock crab (Metacarcinus gracilis, aka Cancer gracilis). Woohoo! Thanks to Steve at Blue Jay Barrens (link has been removed as he is no longer blogging), I now have a book that keys out this crab, but I had the preconceived notion that Cancer crabs were much, much larger and didn't believe the key. Of course, it's always easier to double-check keys once you know the answer.

grunion greeting, 2010 #4

grunion greeting
new moon cycle, 10:40-11:35pm, clear skies

No grunion, but it was an interesting time, nonetheless. There were a lot of cars on the lower part of the pier with very few obvious fishermen... maybe because it was Saturday night, or the hot weather kept people out on the beach with bonfires, or a delayed airing of the World Cup was playing at the pub on the other side of the pier. With all the lights and no Charlie sighting this year, we didn't expect to see much grunion activity. We did see a couple fancy schmancy, lighted, remote-controlled flying toys and hundreds of small sand crabs in the surf.

lined shore crab ~ 02/24/10 ~ Coast Guard Pier

lined shore crab
Pachygrapsus crassipes

I always wondered what these crabs were. They're fun to watch as they froth foam from their mouths with the bigger pincher. It really has helped me to look these things up. I believe that's a common sea star (Asterias forbesi) in the lower left of the second pic.

grunion greeting, 2009 #7

graceful rock crab
Metacarcinus gracilis (aka Cancer gracilis)

full moon cycle (11:05pm - 12:35am), partly cloudy skies

We arrived at Del Monte Beach at 10:35pm. The private cruise ship The World was there again to light up the waters. There were 4 adults and 1 boy out in the water catching grunion. Another group of young people and their dog, which happily ate a grunion, stopped by to check out what was going on. Diane and her coworker Steve also arrived ~11:30pm and walked down the beach together. I felt badly Steve didn't get to see a live grunion except for in a bucket. Before we left at 12:15am, our friend Charlie the night heron came to visit, but there was still too much going on for him to hang around much.

We saw 15 grunion total, with 11 of those showing up before the 11:05 high tide mark. Most were within 25 yards of the pier and at about the 7th parking meter from the bathroom (it didn't seem as high of a tide as during the new moon). We also counted 6 small crabs ~2" wide. This was the first time we've noticed crabs. They floated in on a wave and then quickly buried themselves in the sand. I tried to pick one up, but its pinch was pretty strong for such a little crab.

I talked with one fellow who was collecting and he seemed to know quite a bit about the grunion, including the behavior of scouts. He witnessed a huge grunion run with silvery flashes as far as the eye could see down the beach in June or July of 2007 on a full moon. His girlfriend confirmed the year. There was a beach party at the Adventures by the Sea rental and birds were lined up all along the shore. He said the air smelled like cucumber and noted that happens whenever there's a big run (I found this observation particularly interesting). He said as more people came out to check the run, it seemed to him that there were fewer grunion. He walked down the beach to the cement structure where it was darker and quieter and found even more grunion than by the pier. My husband was excited to hear this part of the story, because he suspected the cement structure would be a prime grunion "hot spot."

The 4 adults arrived a little after 10:00pm and collected 22 grunion. I know they saw quite a few more, because they were having a hard time holding onto the wiggly grunion. They planned to fry the fish whole. The boy managed to catch 3 grunion until his family came to drag him home.

I can't help but wonder if all the grunion collecting and activities stalled a big run from occurring these 2 nights.

ps 10/07/10 - I originally posted the above as an unknown crab. Thanks to a better picture from another grunion greeting night, I was able to ID this crab.

hermit crab ~ 06/04/09 ~ Shoreline Park

hermit crab

While exploring the tide pools along Oceanview here in town, we played with the hermit crabs. This one popped out of its shell and mooned me. He quickly slipped right back into his shell when I dropped him back into the water. We pried small limpets off the rocks and instigated food fight frenzies amongst the hermit crabs. It was great fun!