Another beautiful view of dense kelp in the low intertidal zone on the Mendocino coast — this one is Winged Kelp (Alaria marginata).
Thursday, May 24, 2018
Tuesday, May 22, 2018
After field work near Mendocino on Sunday, we were walking up a coastal bluff and noticed some shallow pools off to the side of a small stream running along the rocks towards the ocean. Looking down, some movement caught our eye:
Little wriggling tadpoles!
We followed the stream up to a small wet seep near the bluff. Soon we saw tiny, newly-metamorphosed froglets (~1 cm long) jumping among the vegetation.
This one landed and nestled on the leaf of a Seep Monkeyflower (Mimulus guttatus):
And here's one with wet feet:
Good luck little treefrogs!
Sunday, May 20, 2018
P.S. For a little more information about this species, see the previous post called "Puckered up" from 22 August 2012.
Saturday, May 19, 2018
Rough Limpets (Lottia scabra) are known for having home scars — a site that the limpet returns to consistently when not foraging.
Home scars can be multi-dimensional, with the upper level of the home scar fitting the shell margin, and the lower level fitting the shape of the foot. The scars are often eroded into rock, although in the case shown above, the form-fitting scar is worn into a layer of pink crustose coralline algae.
Can you see how this intertidal limpet fits into the scar (at the left) by matching the shape of the shell to the outline of the home scar?
Scientists studying the benefits of home scars have shown that the scars can prevent desiccation, reduce predation (with many predators, but not all), and increase survival after burial by sand.
P.S. If you're curious about orientation, the head of the limpet is at the narrow end of the shell.
Friday, May 18, 2018
Every now and then you get to see something really special. Yesterday, Dane let us know that Aaron Orsini, a local fisherman, had found a mysterious cephalopod in a crab trap. It was brought to the marine lab where the Aquatic Resources Group identified it.
What a beautiful animal! This is a North Pacific Bobtail Squid (Rossia pacifica). Luckily, Eric had a few minutes to take some pictures and some video (don't miss the video clip below!).
Bobtail Squid are impressive color-changers. Sometimes the squid appeared almost white; other times it was brick red. (Watch the video clip to see the waves of color spread across the body.)
This animal spent a lot of time on the bottom, which might make you wonder if it's an octopus. But then it would start swimming and its fins would be revealed (watch for the fins in the video below). Octopus generally lack fins (with the exception of some specialized deep-sea octopus).
Bobtail squid are not true squid, but are actually more closely related to cuttlefish (but not the same as cuttlefish). Note that the body of the bobtail squid is short and rounded and that the fins are also rounded and attached midway along the mantle. In contrast, the bodies of most true squid are elongate and the fins are attached further back. [And although not visible, the internal shells of bobtail squid are rudimentary and chitinous, rather than well developed like the "pens" of true squid or the calcareous internal shells (or "cuttlebones") of cuttlefish.]
A few fun facts about North Pacific Bobtail Squid:
- They're distributed along the Pacific Rim, from Japan to the Aleutian Islands to Baja.
- They're primarily subtidal, living at depths from ~10-300 meters, on sandy or muddy bottoms. (They're known for burying themselves in the sand.)
- They're pretty small — the mantle (portion of the body behind the head) reaches lengths of ~3-5 cm (females are larger than males).
- They feed primarily on shrimp.
Now for the real treat. Check out this amazing video. We're excited to share this footage of our first observation of a North Pacific Bobtail Squid (also called a Stubby Squid because of its short, rounded mantle.)
In the video, be sure to watch for the amazing color changes caused by the dynamic action of the chromatophores (pigment cells) in the skin. And have you ever seen such beautiful emerald green eyes?
P.S. Many thanks to Aaron, Dane, Bodega Marine Lab's Aquatic Resources Group, and Eric for making it possible to introduce you to Rossia pacifica.
Thursday, May 17, 2018
Wednesday, May 16, 2018
Eric and I were doing some surveys early this morning when we surprised by a Brown Pelican (Pelecanus occidentalis) landing nearby:
The tide was coming in, so we kept surveying, but I took one quick photo of "Spike" for the record (note the spiky feathers on the back of the pelican's head):