When serendipity strikes, I try to go with the flow and ride it as long as I can. The latest wave is my batch of Dermasterias larvae, which are developing nicely for the first four days of life. And now they look just like jellybeans!
They have complete guts now and have already grown a bit, measuring 400-430 µm long. It's not always easy to catch these guys in the right orientation to take a photo, as they are spinning and swimming through three-dimensional space, but I got lucky:
I did try to follow an individual larva as it swam around on a microscope slide. I confined the larvae to a single drop of water under a cover slip so their movements are a bit constrained, but they manage to swim along fairly quickly. The resulting video might be a little nausea-inducing, so don't click on it if you're susceptible to motion sickness.
For now I've got the larvae divvied up into different feeding treatments. More on that later.
Actually, it was a fortunately placed phone call from an aquarium curator that struck the other night. I was at home, having eaten dinner and reviewed my lecture for the following morning, when my phone rang. It was the curator, saying that he was making his last rounds of the evening and had noticed that some of his sea stars were spawning. Echinoderm sex--more specifically, the opportunity to collect gametes and observe larval development--always grabs my attention, so I told him I'd throw on some shoes and meet him at the marine lab in five minutes.
Lo and behold, there were leather stars (Dermasterias imbricata) spawning in several of the tanks and seawater tables. Many of the tables were cloudy with sperm, but I found only one female, which seems strange but isn't so unusual. These spawning events occur in response to some environmental cue, such as day-length, a chemical of some sort, or the phase of the moon. When a sea star (or sea urchin) spawns it also releases chemicals that trigger spawning in nearby conspecifics, as to spawn by oneself is an enormous waste of energy. A single spawning animal can result in all the others of its kind spewing out huge numbers of gametes in an orgy of passive sex. However, an animal can be induced to spawn only if its gonads are ripe. Ripeness depends on the overall health of the animal and requires adequate food; animals that don't receive enough food don't have energy to allocate towards gamete production. As eggs are energetically expensive to produce, compared to sperm, it is not unusual for males of a species to mature earlier in the reproductive season than the females. In Washington the spawning season for D. imbricata is April-August. Here in California the reproductive season hasn't been clearly defined, but I do remember a springtime spontaneous spawning event in the lab several years ago.
That creamy looking mass of goo on the star's aboral surface is a pile of eggs. Sea star eggs are fairly large, compared to the urchin eggs I'm used to, and sticky. They tend to clump together in stringy globs until they are dispersed by water currents. The star whose arm is photobombing in the lower right corner is a male. He was also spawning copiously and is probably the individual who fertilized most of this female's eggs.
Given the lateness of the hour and the fact that I had to get up early the next morning I didn't take many pictures of the eggs, although I did look at them to make sure they were fertilized. They were, so I put them into a 1000-mL beaker of seawater and let them do their thing.
Fast forward to today, about a day and a half after fertilization. About two-thirds of the embryos had hatched and were swimming in the water column. Here's what they look like under the dissecting scope:
I poured off the swimmers into jars and set them up on the paddle table. I gave them a little bit of food, in case their mouths break through before I can get back to the lab tomorrow afternoon. In the meantime, I took a sample of embryos and examined them under the microscope. They look really cool!
The embryos are almost spherical, measuring 290 µm long and 270 µm wide. They are ciliated all over and swim with the rounded end forward. The flattened end is where the process of gastrulation started. That visible invagination begins at a section of the embryo called the blastopore; the channel is the archenteron, the first gut of the larva. In echinoderms, as in chordates (including us humans), the blastopore will end up being the larva's anus; the mouth breaks through later at the other end of the archenteron. This is why I don't need to start feeding the larvae right away even though their gut has begun forming.
Tomorrow afternoon I'll have a brief window of time when I can check on the larvae and see how they're doing. I think they may have complete guts by then!
At this time of year low tides occur in the afternoon. Later in the spring they will shift to mornings. There are a few reasons that I really prefer morning low tides to those that occur in the afternoon: (1) the time of the low gets about 50 minutes later every day, so as the tide series progresses you start fighting loss of daylight; (2) the wind tends to pick up in the afternoon, making it colder and causing ripples on the surface of pools that make it difficult to see; (3) the intertidal is more crowded with human visitors on the afternoon lows. I had decided to use today's low tide to photograph a particular clump of barnacles at Natural Bridges, and figured that it would be a quick trip because all the extraneous human activity would get on my nerves.
Turns out I found my barnacle clump pretty quickly, but it had been overgrown with tube worms (Phragmatopoma californica) and I wasn't sure I could see the trait that I was looking for.
At least, I'm pretty sure I was in the right spot, looking at the same barnacles I'd seen in January. In any case, this year for whatever reason we have a bumper crop of Phragmatopoma. They are very abundant and appear to be expanding their range within the intertidal. Somebody should be keeping an eye on that. Ahem.
It was a beautiful afternoon, so when I had finished taking photos for "work" I sat around to bask in the sun and watch the surf.
As I sat quietly, the animals got used to my presence and went about their business as if I weren't there. To me this is one of the best things about being in nature, the opportunity to disappear and watch animals do their thing without being noticed.
After this bird cooperated so nicely, I challenged myself to catch as many different bird species in a single photograph. I got three in a single frame, twice:
Pelicans are so cool. Their populations were hit hard by DDT but have recovered beautifully in recent decades. To watch them skim the waves is one of life's great pleasures. But my favorite photo of all the pelicans I shot today was this one of a pelican against the afternoon sky:
The luck with birds didn't stop when I left the beach, either. As I was walking back I came across a great blue heron (Ardea herodias) standing so still that at first I thought it was a statue even though I knew there wasn't a statue in that spot.
When all was said and done, it ended up being a good afternoon. I got my attitude adjusted, saw some cool stuff, and left the intertidal feeling better than I did when I arrived. Thank you, Mother Nature, for the much-needed trip outside myself and opportunity to get my head straight.
Today my students and I visited the Monterey Bay Salmon and Trout Project hatchery, to learn about local efforts to save the federally endangered coho salmon (Oncorhynchus kisutch). The coho is one of five species of Pacific salmon found on the coast of North America, the other four being the Chinook (O.tshawytscha), the chum (O. keta), the sockeye (O. nerka), and the pink (O. gorbuscha). The coho's range extends in the North Pacific from northern Japan up along Russia, across the Aleutians, and down the coast of North America to the northern bit of Monterey Bay. In our area the coho return to their natal streams (Scott Creek, Big Creek, and occasionally the San Lorenzo River) during the winter rains in January and February.
The local population of coho make up an evolutionarily significant unit (ESU). This means that they are locally adapted to the extent that they are biologically and genetically distinct from other populations. For example, coho from Alaska, where they are much more common, cannot be successfully transplanted into our watershed because they are genetically programmed to spawn in the fall, the time of year when our streams are dry or disconnected from the ocean due to sand bars. So these fish aren't just any old salmon. They have evolved to live in this particular watershed and as such are irreplaceable.
Our first stop of the morning was to the fish trap on Scott Creek. The weir, the structure that extends across the river in the photo below, traps fish that are swimming upstream. Once on the upstream side of the weir, the fish are directed into the cage, from which they can be removed so that fisheries biologists can collect life history data--species, sex, weight, length--before they are released to continue their journey upstream (if they are steelhead) or transported to the hatchery to be spawned (if they are coho).
No fish were in the trap when we got there this morning but our host, a NMFS biologist named Erick, told me that eight coho had been caught yesterday. We did see a pair of steelhead swimming in the water upstream of the weir. Anytime I see a fish out of water, I forget how difficult it is to find them when they're in their natural habitat. The spots on a steelhead's back blend in perfectly with the ripples of the water and the gravel of the stream bed.
Do you see two faintly reddish blurs in the photo above? Those are the fish. They are facing upstream, to the right. The larger fish on the top is the female.
After the visit to the fish trap on Scott creek we drove up to the hatchery, which is located along Big Creek. The hatchery's day-to-day operations are run by a couple of people from MBSTP. During the busy seasons staff and interns from the NMFS lab in Santa Cruz work up there, too, so the little hatchery building gets quite crowded. We were fortunate to get to see pretty much all the steps involved in trying to return an endangered species from the brink of extinction.
Male salmon, called bucks, are held in pens outdoors. They can contribute more than one sperm donation in a season, just as in the wild a male can fertilize the eggs of more than one female. A buck is taken from the pen, sedated, and then is milted for his sperm. The milt is collected into a glass test-tube and kept dry; once the sperm make contact with fresh water they become activated, and there is a 30-second window during which they can fertilize eggs. Sperm can also be damaged by exposure to UV radiation, so the test tubes are always held in a closed hand. Back inside the hatchery building Erick takes a look at the sperm under a microscope to make sure they can swim properly.
Female salmon are called hens. Before eggs are taken the hens are anaesthetized and examined by palpation and ultrasound to confirm that their eggs are mature. A sample of ovarian fluid is taken and sent off to be tested for disease. When a hen passes the ripeness test she is sliced open to release her eggs into four metal basins.
A single female's eggs are fertilized by the sperm of four males. The fisheries biologists keep a detailed matrix of who mates with whom, so that they can avoid additional inbreeding in a population of fish that has already undergone a genetic bottleneck. Milt that has been collected from broodstock males is placed over the eggs. Fertilization occurs once fresh water is added to the basin. The egg-sperm combination is swirled ("just like panning for gold," Erick explained) for two minutes, then the eggs are rinsed and disinfected before being placed into a 100% humidity cold incubator held at 11°C.
The eggs remain in the incubator until the embryos have developed eyes. Then they are transferred into trays through which water flows. When they've absorbed most of their yolk sac they get placed into large indoor trays where they will be fed until they are big enough to go into the outdoor tanks. They'll spend about a year in the outdoor tanks and should then be ready to undergo the process of smoltification, during which their physiology undergoes the alterations necessary for the transition to marine life.
When I took last year's class to the hatchery we didn't get to see much activity because there were so few fish returning due to the prolonged drought and low water in the creek. This year's El Niño, which has brought rain, has also made it possible for the fish to get into the creeks. Coho are a 3-year species, so the fish returning this year were born in 2013. These fish outmigrated as smolts into drought conditions, and fortunately for them they return during a rainy year. Their progeny will outmigrate in 2017, hopefully into a strong upwelling which will produce lots of food. And when they return in 3-4 years, I hope that there is enough rain for their creek to flow.
This past weekend I participated for the first time in the Audubon Society's Great Backyard Bird Count, in which ordinary folks spend at least 15 minutes observing birds in their own yards. Turns out you can also observe in other sites, but I opted to watch birds from my back deck. As my house backs up to a more or less wild arroyo, I decided to count the entire canyon as my backyard. I'm neither clever nor coordinated enough to take photos while trying to identify birds, so I have no pictures to share with you. I do, however, have data!
Saturday 13 February 2016, 16:51-17:18
Saw and was able to identify:
American robin (Turdus migratorius)
Dark-eyed junco (Junco hyemalis)
Oak titmouse (Baeolophus wollweberi)
Golden-crowned sparrow (Zonotrichia atricapilla)
Red-tailed hawk (Buteo jamaicensis) - nesting in a eucalyptus tree across the canyon!
Fox sparrow (Passerella iliaca)
California towhee (Melozone crissalis)
House finch (Carpodacus mexicanus)
Northern mockingbird (Mimus polyglottos)
Anna's hummingbird (Calypte anna)
Heard and was able to ID:
Western scrub jay (Aphelocoma californica)
California quail (Callipepla californica)
Northern flicker (Colaptes auratus)
American crow (Corvus brachyrhynchos)
Sunday 14 February 2016, 12:14-12:33
Saw and was able to ID:
Red-tailed hawk (the same nesting pair)
Wrentit (Chamaea fasciata)
Turkey vulture (Cathartes aura)
Heard and was able to ID:
Chestnut-backed chickadee (Poecile rufescens)
Red-shouldered hawk (Buteo lineatus)
Monday 15 February 2016, 16:57-17:27
Saw and was able to ID:
Red-tailed hawk (in nest)
Purple finch (Carpodacus purpureus)
Western scrub jay
Heard and was able to ID:
Bushtit (Psaltriparus minimus)
Northern flicker (Colaptes auratus)
All told, in the three observation periods I identified a total of 20 birds from my backyard. Granted, what I'm calling my "backyard" is a lot bigger and more wild than most, which is why I love living where I do: I get to look down to watch birds in flight. I have no idea if 20 is a lot or a few bird species to see at one time in a single location. There are at least that many other species I see commonly or occasionally but that didn't show up this weekend.
This little project helped me validate my intuition by demonstrating that the middle of the day is not the best time to watch birds if your goal is to see lots of different birds. Clearly, more birds are active in the early evening than during midday. I intended to have a sunrise observation period but never managed to get my act together enough to pull it off. I would expect perhaps as many species as in the early evening, but not necessarily all of the same species. As I write this I can hear the hooting of a pair of great horned owls, audible even over the din of the chorus frogs. The owls hoot back and forth to each other, sometimes all night and into the hour or so before sunrise. Even though I've never seen one, it makes me happy to know that they're in my backyard, along with the raccoons, skunks, opossums, nesting hawks, deer, and the occasional bobcat (and who knows, maybe even a mountain lion every once in a great while). I am fortunate to have all of this nature literally right outside the back door. I do indeed live in paradise.
While much of America was glued to the television watching a football game, I went out to the intertidal at Davenport Landing to do some collecting and escape from Super Bowl mania. The Seymour Center and I have a standing agreement that some animals--small hermit crabs and certain turban snails, for example--are always welcome, which gave me an excuse to look for them. I also needed to pick up some algae for labs that I'm teaching later this week, so it was an easy decision to be alone in nature for a couple of hours.
As usual, I was easily distracted by the animals, especially the anemones. They are simply the most photogenic animals in the rocky intertidal. And we have an abundance of beautiful anemones in our region; I feel very lucky to photograph them where they live. I would like to share them with you.
First up, Anthopleura sola:
Second species, Anthopleura xanthogrammica:
Along the central California coast we have four species of anemones in the genus Anthopleura. Two of them, A. xanthogrammica and A. sola, are large and solitary; in other words, they do not clone. The geographic ranges of these two species overlap in central California. Anthopleura xanthogrammica has a more northern distribution, from Alaska down to southern California, while A. sola typically lives from central California into Mexico.
I've seen these congeneric anemones living side-by-side in tidepools at Natural Bridges and at Davenport. Here is a photograph from yesterday. The animals are almost exactly the same size, and are separated by about 30 cm. Can you tell which is which?
The pièce de résistance yesterday was a treasure trove of Anthopleura artemisia anemones. I'd seen and photographed them several times before, and always appreciated the variety of colors they come in. For some reason, though, yesterday they really caught my eye. I had a number of "Wow!" moments.
Sometimes two colors are combined:
Stunning, isn't it?
But this next anemone is unlike any I've ever seen before. Get a load of this:
These stark white tentacles are new to me. The anemone measured about 4 cm across. In every other aspect it looks like A. artemisia, and I'm almost entirely certain that's what it is. It does feel special to me. I will hopefully be able to keep an eye on this individual and see if its colorless tentacles are a temporary or long-term condition. And now that my eye has been primed to see the colors that A. artemisia comes in, I may notice more unusual color morphs.
One of the best things about teaching is the opportunity to keep learning. Case in point: yesterday I attended an all-day teacher training session for the LiMPETS program, so that I can have my Ecology students participate in a big citizen science project in the rocky intertidal later this spring. In the Monterey Bay region LiMPETS is organized and run out of the Pacific Grove Museum of Natural History, where yesterday's training took place. LiMPETS has two ongoing citizen science projects, one looking at populations of mole crabs (Emerita analoga) on sandy beaches and the other monitoring population of several invertebrate and algal species on rocky shores. Of course, my interests being what they are I signed up for the rocky intertidal monitoring project.
We spent the morning learning about the history of the program and how to identify the organisms that are monitored, then after lunch went out to Point Pinos to collect some data and work through the process that we need to teach to our students. The day before we'd had a high surf advisory on the coast, and yesterday the swell was still big. We hiked out to the study site and set up the transect line, which runs from the top of a rock through the entire range of tidal heights to the low intertidal.
Where Emily is standing is about 10 meters along the transect line. The monitoring protocol calls for sampling at every meter on the transect. One of the other teachers, Phaedra, and I were the only ones wearing hip boots, so we volunteered to work at the lowest spot. We thought we'd start with the 10-meter quadrat and hopefully get down to the 11-meter quadrat once the tide receded a bit more. Then we got hit by a few big waves and decided that discretion is the better part of valor and gave up. It was a pretty easy decision to make, especially after the quadrat got washed away and we had to go fetch it when the waves brought it back.
All told the group collected eight quadrats of data. We had a little time to poke around (i.e., take pictures) before heading back to the museum for data entry.
Codium is an interesting alga. These cylindrical structures are composed of many filaments, which in turn contain multi-nucleate cells. Yes, the cells contain multiple nuclei. Codium fragile has the common name "dead man's fingers," I suppose because. . . well, I actually have no idea. As far as I can tell they don't feel anything like a dead man's fingers, or the way I imagine a dead man's fingers would feel.
There were quite a few empty abalone shells scattered among the rocks. As we were hiking out I found this shell. When I tried to pick it up I found that it was still alive, and well stuck to the rock. This is a very good sign, as the black abs have been suffering from withering syndrome, in which the animal gradually loses its ability to hang on.
All in all, this workshop was a lot of fun. If I have to give up an entire Saturday to do training, it couldn't get much better than spending at least part of it in the intertidal. And Point Pinos is such a fabulous intertidal site that I certainly wouldn't turn down an opportunity to explore there again.
Thursday is the day that our trash and recycling/green waste bins get emptied. This afternoon I was moving my green waste bin out to the curb and discovered three little creatures living under it. Two of the three guys were the same, and the third was something different. Fortunately none of them had been injured when I rolled the bin out of its spot next to the fence. The two little guys stayed put when I ran inside to grab my camera, but when I came out the largest guy had disappeared. I found it curled up next to the inside edge of one of the wheels on the bin and was able to coax it out for a few pictures.
A bit of research on the mighty Interwebs leads me to conclude that the larger of my new damp friends is a California slender salamander, Batrachoseps attenuatus. It certainly is slender, isn't it?
If it weren't for the tiny legs, at first glance this guy would look like a snake. Here's a close-up of its front end (and the palm of my hand):
All told, the slender salamander was about 15 cm long. It fit very nicely in my hand.
The two other critters were quite small, about 3 cm long, and more typically salamander-shaped. I'm pretty sure they were the same species but juveniles can be difficult to identify. They were dark gray, almost black, with tiny yellow speckles that I thought at first were dust bits. Looking at the photos now I'm pretty sure at least some of them were speckles, though.
Cute little guys, aren't they? Aneides lugubris gets its common name from the fact that it can and does climb on trees. However, they are more commonly seen on the ground. Like all salamanders they must remain moist because they breathe through their skin, so they are found under wood piles or flower pots or other yard structures. Including green waste bins, apparently.
I had to remove these guys' shelter to the curb, so I gently scooped them up, handling them as little as possible, and transferred them to the flower bed. I hope they'll be happy and can find shelter there.
I love the serendipity of finding creatures when I didn't expect to! Especially when they're creatures I'm not familiar with. Any chance to learn about something new is fine by me!