Guess who?

Time for a close-up mystery photo!  

Do you have ideas about what type of organism this is?  

[I'll reveal the answer tomorrow night.]

 

Sunrise in the western sky

 

The moon in the western sky at sunrise, as seen from Cotati on 14 February 2017.

Pink roses

 

Although there were more Hopkins' Rose (Okenia rosacea) nudibranchs around in 2015 and 2016, there are still some individuals present in the Bodega Bay area.  This one was photographed on 12 February 2017, when we spotted 8 others during a survey in the rocky intertidal zone.

For some background information about these nudibranchs, review the post from 3 January 2015.

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Happy Valentine's Day!  

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Scarlet fire

 

About two years ago, I shared a post about the Scarlet Sea Cucumber, Lissothuria nutriens (see post on 22 January 2015).  At that time, I noted this species was rare in Bodega Bay, but we also wondered if this southern sea cucumber might increase in abundance if sea water temperatures became warmer.  It appears that has happened!

The Scarlet Sea Cucumber reaches its northern range limit in Bodega Bay.  There are some records from Duxbury Reef in Bolinas, but so far we haven't been able to find any records from further north.  (This would be a good time to look for them in northern California!)

Remember that this is a small sea cucumber.  Here's a picture from the rocky intertidal zone with some fingertips for scale.  It shows several Scarlet Sea Cucumbers on the rock — look for three reddish blobs in the center of the picture:

 

When the cucumbers are out of water, their tentacles are retracted.  And note that they cover their bodies with bits of debris.  (Recognizing this "covering" behavior is helpful when searching for these sea cucumbers — it differentiates them from red sponges and sea squirts.)

Here's another example, this time a close-up of a single Scarlet Sea Cucumber:

 

Because this species has been rare in our area, we wanted to be certain about the identification.  So Eric double-checked the ossicles (the calcareous plates inside the body wall, tube feet, and tentacles that help identify different species of sea cucumbers).

Below is a diagram illustrating the different types of ossicles found in Scarlet Sea Cucumbers:

 

Ossicles of Lissothuria nutriens.  (A) Curved supporting plate from tube foot, (B) end plate from tube foot, (C) smaller, hourglass-shaped bodies from dorsal body wall.  Modified from Deichmann, E. (1941).  The Holothuroidea collected by the Velero III during the years 1932 to 1938. Part I. Dendrochirota.  Allan Hancock Pacif. Exped. 8: 61-194.

For comparison, here are a few of the ossicles from one of the local specimens.  You can see that the shapes match the drawings above, confirming the identification:

 

If you get lucky and spot a Scarlet Sea Cucumber in a tidepool, along with the red oblong body you might see the tentacles extended.  Interestingly, the tentacles vary in color from fiery orange to scarlet red:

 

These sea cucumbers feed by catching organic material on their tentacles and then moving it to their mouth in the center of the tentacles.  Eric filmed some of this behavior under a microscope in the lab, and he made a wonderful video clip so that you can see the tentacles in action.  (Also watch for the shiny ossicles embedded in the tentacles and tube feet.)

scarlet_sea_cucumber_sanford from Jackie Sones on Vimeo.

We have counted quite a few Scarlet Sea Cucumbers in the low intertidal zone while conducting surveys this past week.  We're also wondering if the warm ocean temperatures during the last couple of years might have allowed this species to move even further north, beyond Bodega Bay.  We'd be very interested in any Scarlet Sea Cucumber observations in northern California, so let us know if you spot one!

 

Solar-powered

Air temperatures in Bodega Bay reached ~56°F (~13°C) this afternoon.  After a week of rain, it seemed like a lot of insects were taking advantage of the sun today:

 

Red Admiral (Vanessa atalanta)

 

Monarch Butterfly (Danaus plexippus)

 

Variegated Meadowhawk (Sympetrum corruptum)

 

Unidentified fly (Let me know if you recognize it!)

ADDENDUM (12 February 2017): One of the suggestions I received about the fly in this post was that it could be a hover fly.  I did a quick image search, and noticed a similar-looking hover fly here.  I don't think it's the same species (based on the abdominal patterning), but it's very close, and I think it's likely the fly in the picture above is in the same family (Syrphidae).

Then I skimmed some information about syrphid flies, and learned that sometimes they eat aphids.  In the field I had noticed that these flies were spending a lot of time around the tips of the Monterey Cypress.  I wondered about what they were doing there (i.e., what was attracting them to those sites).  Well, I went back and reviewed my photos and it looks like there might be tiny aphids on the cypress tips!  Check it out — and note the arrow pointing to one of the possible aphids:

 

End of the day

 

Sunset reflections, 10 February 2017

In the rain

 

Peregrine Falcon in the rain, 7 February 2017

We've had quite a winter.  Today we reached a total of ~38" of rain since July 1st in Bodega Bay.  The average annual rainfall for this area is ~31".  Who knows what the next couple of months will bring, but we're on track to receive one of the highest annual rainfall amounts on record.  Will we reach or surpass 46", the amount recorded in 1997?