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Today is Monday, which means Scott and I changed the water for our Pisaster larvae. I should have taken some pictures to show you how we do it. Maybe next time.

The largest and most developed larvae are now 2.2-2.5 mm long, not including the long brachiolar arms, which is about as big as they're going to get. They are still eating and developing their juvenile rudiments. Unlike the sea urchin's pluteus larva, these brachiolaria larvae lack any kind of skeletal structure and are entirely squishy--they bend and flex along any axis and can scrunch into surprisingly tiny balls. Those long arms are flexible as well, and sometimes the larvae swim around with their arms tucked or rolled up. I haven't been able to catch them in the act with the camera, but both Scott and I have seen the larvae react to encountering a surface by flipping the long arms around as though doing the backstroke.

If a picture is worth a thousand words, then how much is a video worth?

The weird alien-like effect is enhanced by the dark background I film them against. Except for their guts and the tips of their arms, the larvae are entirely transparent, which makes it difficult to photograph them. The black velvet that I use as a background, combined with lighting from an oblique angle, maximizes contrast and makes the transparent bodies more visible. The little illuminated "stars" in the background are actually part of the texture of the velvet.

To capture this video I shrunk the larvae's universe into a single drop of water on a depression slide. This means they couldn't swim too far out of the field of view and would have to bump into each other. Don't worry, though, after the photo shoot I returned the larvae to one of the jars and let them swim away. They'll be just fine.


A recent college graduate and fellow marine lab denizen (Scott) and I are collaborating on a project to quantify growth rates in juvenile Pisaster orchraceus stars. This is one of the intertidal species whose populations in the field and in the lab were decimated by the most recent outbreak of sea star wasting syndrome (SSWS). We are interested in seeing how quickly the stars grow once they metamorphose and recruit to the benthos, and hope that the information will help researchers guesstimate the age of the little stars that are now being seen in the field. This would in turn tell us whether the little stars are survivors of SSWS or post-plague recruits. I keep seeing people refer to them as "babies," but they could very well be several years old. We just don't know, hence this study.

Large, healthy specimen of Pisaster ochraceus at Davenport Landing. 20 May 2015. © Allison J. Gong
Large, healthy specimen of Pisaster ochraceus at Davenport Landing. 20 May 2015.
© Allison J. Gong

But before we get to measure juvenile growth we have to get through larval development, which is perfectly fine by me because I'm always up for observing marine invertebrate larvae. Two weeks ago Scott and I ventured into the field in search of prospective parents. We brought back eight individuals from two different sites, making sure to leave many more in place than we took away. It was actually rather gratifying to see how many hand-sized-or-larger P. ochraceus there were. This morning we met at 07:30 to shoot up the stars with magic juice and then wait for them to spawn.

We have injected the stars (Pisaster ochraceus) and are waiting for them to spawn. 2 June 2015 © Allison J. Gong
We have injected the stars (Pisaster ochraceus) and are waiting for them to spawn. 2 June 2015.
© Allison J. Gong

It has been a while since I tried to induce spawning in Pisaster, and I had forgotten how much longer everything takes compared to the urchins. For one thing, the magic juice itself isn't the same stuff that we use on the urchins, and works by an entirely different mechanism. The stars' response to the magic juice takes 1.5-2 hours, whereas if the urchins aren't doing anything 30 minutes after getting shot up they either need another injection or simply don't have gametes to share.

However, despite my misgivings the animals spawned. Two large females gave us enormous quantities of eggs, and three more donated trivial amounts that we didn't end up using.

This purple individual is the one we designated Female 1. See the huge piles of salmon-pink eggs?

Large purple female Pisaster ochraceus, spawning. 2 June 2015 © Allison J. Gong
Large purple female Pisaster ochraceus, spawning. 2 June 2015.
© Allison J. Gong


Large orange female Pisaster ochraceus, spawning. 2 June 2015 © Allison J. Gong
Female 2, a large Pisaster ochraceus, spawning. 2 June 2015.
© Allison J. Gong

Although we had to wait for a male to spawn, we finally did get some sperm and fertilized the eggs at about 12:30. Another thing I had forgotten was that Pisaster eggs, when shed, are lumpy and strange. I was used to the urchin eggs, which are usually almost all beautifully spherical and small. The stars' eggs are about twice as big, at ~160 µm in diameter. The lumpiness doesn't seem to hamper the fertilization process, as you can see below.

Fertilized eggs of Pisaster ochraceus, 2 June 2015 © Allison J. Gong
Fertilized eggs of Pisaster ochraceus, 2 June 2015.
© Allison J. Gong

In this photo you can see the fertilization envelope surrounding most of the eggs. In stars the perivitelline space (the space between the egg surface and the fertilization envelope) is very narrow, which makes it difficult to see the envelope; in urchins the space is much larger, and as a result the envelope quite conspicuous. The rising of the fertilization envelope off the surface of the egg is referred to as the slow block to polyspermy, a mechanical barrier that keeps multiple sperms from penetrating any individual egg. There's also a fast block to polyspermy, but it happens on a molecular level milliseconds after a sperm makes contact with the egg surface; you can't see it happen in real time.

Cleavage in stars proceeds much more slowly than it does in urchins, too. In embryological terms, "cleavage" refers to the first several divisions of the zygote, during which the cell number increases as the cell size decreases. This inverse relationship between cell size and number logically has to occur because the embryo can't get any larger until it has a mouth and begins to feed, which won't happen for at least a couple of days. It took our zygotes about four hours to undergo the first cleavage division.

2-cell embryo of Pisaster ochraceus, 2 June 2015 © Allison J. Gong
2-cell embryo of Pisaster ochraceus, 2 June 2015.
© Allison J. Gong

I left the slide on the microscope to warm up and speed development a bit, and about 45 minutes later was rewarded with this mishmash of embryos at different stages. Nine hours after we started this whole process, there were 2-cell, 4-cell, and 8-cell embryos, as well as eggs that had not divided yet.

Embryos of Pisaster ochraceus, about four hours post-fertilization. 2 June 2015 © Allison J. Gong
Embryos of Pisaster ochraceus, about four hours post-fertilization, 2 June 2015.
© Allison J. Gong

This asynchrony in early development is another way that stars differ from urchins, and it takes some getting used to. I expect that development will become more synchronized as the embryos continue to cleave, and that hatching will occur for all of them at about the same time, probably before Thursday. At least it won't take another 9-hour day to see how far they've come.


Well, fame is all relative, right?

VICE magazine's May 2015 issue is focused on environmental crises of various kinds. One of the feature articles is on sea star wasting, which I've blogged about before, beginning in September 2013. The author of the VICE article, Nathaniel Rich, came out to the marine lab and interviewed me and some other folks back in February, and a photo crew came out to do a shoot in March.

Here's the article. Overall I think Nathaniel did a good job; this is one of the better lay person articles I've read about wasting. He was able to convey the concern we biologists have about wasting, and the effects it could have on the ecology of the intertidal and subtidal marine habitats, without being too alarmist.

There is one glaring mistake in the first part of the article, which I'm positive must be a misunderstanding of something that I may have said to him. Can you find it?

The temperate rocky intertidal is about as colorful a natural place as I’ve seen. Much of the color comes from algae, and in the spring and early summer the eye can be overwhelmed by the emerald greenness of the overall landscape due to Phyllospadix (surf grass, a true flowering plant) and Ulva (sea lettuce, an alga). However, close observation of any tidepool reveals that the animals themselves, as well as smaller algal species, are at least as colorful as the more conspicuous surf grass and sea lettuce.

Take the color pink, for example. Not one of my personal favorites, but it is very striking and sort of in-your-face in the tidepools. Maybe that’s because it contrasts so strongly with the green of the surf grass. In any case, coralline algae contribute most of the pink on a larger scale. These algae grow both as encrusting sheets and as upright branching forms. They have calcium carbonate in their cell walls, giving them a crunchy texture that is unlike that of other algae. They grow both on large stationary rocks and smaller, easily tumbled and turned over rocks.

A typical coralline “wall” looks like this:

Coralline rock with critters, 18 January 2015.  Photo credit:  Allison J. Gong
Coralline rock with critters, 18 January 2015.
© Allison J. Gong

Mind you, this “wall” is a bit larger than my outspread hand. The irregular pink blotches are the coralline algae. Near the center of the photo is a chiton of the genus Tonicella; its pink color comes from its diet, which is the same coralline alga on which it lives. The most conspicuous non-pink items on this particular bit of rock are the amorphous colonial sea squirt (shiny beige snot-like stuff) and the white barnacles on the right.

What really caught my eye today were the sea slugs Okenia rosacea, known commonly as the Hopkins’ Rose nudibranch. Now, it is very easy to love the nudibranchs because they are undeniably beautiful. The fact of the matter is that they are predators, and some of them eat my beloved hydroids, but that’s a matter for another post. Today I saw dozens of these bright pink blotches dotting the intertidal, both in and out of the water:

Okenia rosacea, the Hopkins' Rose nudibranch, emersed. 18 January 2015. Photo credit:  Allison J. Gong
Okenia rosacea, the Hopkins' Rose nudibranch, emersed. 18 January 2015.
© Allison J. Gong
Okenia rosacea, immersed. 18 January 2015. Photo credit:  Allison J. Gong
Okenia rosacea, immersed. 18 January 2015.
© Allison J. Gong

Only when the animal is immersed can you see that it is a slug and not a pink anemone such as Epiactis prolifera, which I’ve seen in the exact shade of pink. But anemones don’t crawl around quite like this:

Whenever I see O. rosacea I automatically look for its prey, the pink bryozoan Eurystomella bilabiata. Lo and behold, I found it! The bryozoan itself is also pretty.

The bryozoan Eurystomella bilabiata, preferred prey of the nudibranch Okenia rosacea. 18 January 2015.  Photo credit:  Allison J. Gong
The bryozoan Eurystomella bilabiata, preferred prey of the nudibranch Okenia rosacea. 18 January 2015.
© Allison J. Gong

Can you distinguish between the coralline algae and the pink bryozoan in the photo? Is it shape or color that gives it away? If you had to explain the difference in appearance between these two pink organisms to a blind person, how would you do it?


As of today, I am cautiously optimistic that the Pisaster wasting disease I've been dealing with for the past couple of weeks has run its course. There has been quite a cost, however, as a mortality rate of 90% leaves me with one lonely star remaining.

The sole survivor of an outbreak of Pisaster wasting disease. Photo credit:  Allison J. Gong 2013
The sole survivor of an outbreak of Pisaster wasting disease.
© 2013 Allison J. Gong

This lone survivor reminds me of Brother John Clyn, a Franciscan monk and chronicler in Ireland who recorded the deaths of his fellow brothers during the Black Death in the 14th century and may have been the only inhabitant of his monastery not to die of the plague. It remains to be seen whether or not my star eventually succumbs and starts wasting away. But given how quickly all the other Pisasters were affected and killed, I think it's a good sign that this individual isn't sick already.

In the meantime, the quarantined Patiria miniata (bat stars) and Dermasterias imbricata (leather star) remain apparently unaffected. Keep your fingers crossed!

The birds do it, the bees do it, and now the frogs are doing it.  There's a small clump of trees between two of the houses across the street, and I think that's where a male Pacific chorus frog has staked his claim.  Every evening for the past few weeks I've heard him singing away.  Often you'll hear several frogs singing at the same time, but this particular guy's call is much louder and more piercing than the others.  What I particularly like about this sound recording is that it begins with a solo, and other frogs join in to make a joyful noise.

The Pacific chorus frog (Pseudacris regilla), sometimes erroneously referred to as the Pacific tree frog, is the only frog that ribbits.  It couldn't possibly be mistaken for anything else.  In fact, its song is so iconic of "frogness" that it is universally used in movies and other Hollywood products taking place anywhere in the world, despite the fact that this little singer lives only along the western coast of the US.

Most Pacific chorus frogs don't live in trees
Most Pacific chorus frogs don't live in trees

Why is it wrong to call these guys tree frogs?  Because they don't live in trees, silly!  At least, not exclusively in trees.  Along the central California coast they live in grassy areas from the coast up into the hills.  I start hearing them in winter, as the rains form puddles and small ponds, but they stop singing when they hear people approaching.  To me, they are part of the soundtrack of spring in California.  While most of the singing happens at night, I often hear them singing during the day at the marine lab.  Many times the males are singing together -- hence the name chorus frogs.

Considering their ability to make a lot of noise, Pacific chorus frogs are little guys.  Big ones are only 5 cm long.  They vary in color from brown to green, and the color of an individual can change throughout the year.  They have a very distinctive dark horizontal stripe that runs through the eye, making them look like, well, chorus frogs.

Pacific chorus frog (Pseudacris regilla) on the stem of a sunflower
Pacific chorus frog (Pseudacris regilla) on the stem of a sunflower

Like all frogs, chorus frogs are tied to water for reproduction.  Once the rains have started, male frogs migrate to wet areas and set up shop.  Their "krick-et" calls attract females, and the frogs pair up and do what comes naturally to most animals in the springtime.  The female lays eggs in calm, still water and the male fertilizes them as they are deposited.  Tadpoles develop in the water and, hopefully, metamorphose into froglets in due time.

Eventually the mating season will end, and the frogs will stop singing until next year's rains.  I will miss them when they go away, but for the next little while the soundtrack of spring will play every evening.



Yesterday I went in for my allergy shots. I've been doing this immunotherapy for several years now, after innumerable yearly bouts of debilitating bronchitis that lasts for 6-8 weeks. Silly me. If I had done the allergy shots back in my 20s, I wouldn't have had to suffer all these years.

My allergy scratch test was. . . interesting, shall we say. The nurse drew a grid on my back and started pricking me with antigens. By the time she got to the end of the first row the pricks on the left had left welts bigger than the box they were in. By the end of the test my back was one big itchy welt. The allergist was impressed. "You are a very allergic young lady!" he pronounced.

The upshot is that I get four shots to cover the environmental allergens--trees, weeds, pollen, dust mites, cats and dogs, and molds. For the past year or so I've also gotten an injection of honeybee venom, since I am a beekeeper and will get stung more frequently than the average person. My progress has been slow because of my overactive immune system, but back in May I reached my maintenance dosages of all five shots.

Yesterday I went in for my shots as usual and felt fine immediately afterwards. By law I have to wait 30 minutes after the shots before leaving so I was just sitting there knitting. Twenty-five minutes into my wait I started feeling flushed in my face and neck, and weird all along my GI tract. The nurse took me back into a room and took my vitals. My blood pressure was low-ish but my O2 sat was fine and my breathing unaffected. Just to be safe they called in the doctor to check on me. He gave me a dose of Benadryl and prednisone.

That must have been about the time my blood pressure started tanking. I remember feeling vaguely woozy and unhappy about the state of affairs. My guts were still griping and I was feeling hot on my face and cold everywhere else. They gave me an IM shot of epinephrine to stop the allergic reaction. The doc said, "This will stop the allergy but make you feel lousy." Boy, he wasn't kidding. My heart was pounding and I was still shivering.

By this time I was lying down feeling sorry for myself. I never lost consciousness but probably would have had I been sitting upright. My blood pressure didn't come back much and I got another shot of epinephrine and they started an IV to get some fluids into me. At this time they called 911 and were starting to look really worried. My blood pressure was about 60/30. That's pretty damn low, even for someone like me whose BP is on the low end of normal anyways. Apparently by the time the EMTs came to get me I was really pale. At least I was able to get onto the gurney myself.

This was my first time inside an ambulance. The EMT, a very nice man named Jorge, tried to start another IV in my other hand but couldn't get it going because my veins had collapsed due to lack of pressure. I was strangely unworried when he told me that. It took about 2 minutes to drive from the allergy doc's office to the hospital, where they set me up in the ER for observation. Since I had been given all the appropriate meds at the allergist's office they didn't give me anything else after I got to the hospital. By that time my BP had risen to 100/70, which is close to normal for me.

"Observation" in the clinical sense means just that. I was left alone for the most part, with a nurse coming in to check my vitals every half-hour or so at the beginning. The ER doc came in at the beginning and I didn't see her again until hours later. She told me they needed to keep me until the effects of the epinephrine wore off, to make sure the allergic reaction didn't start up again. Poor Alex had to take the day off work and sit with me. What a guy! He let me read the Time magazine he had scrounged from somewhere and found me a sandwich to eat. The hospital discharged me at about 4:30 p.m., almost six hours after I had been dropped off.

What does a blood pressure of 60/30 feel like, you ask? It's strange. I could hear my heart thumping because of the epinephrine, but my head was empty feeling and slow. I think I was talking coherently but don't know if I was actually making any sense. My thought process was very slow and I remember having to think about words before I could say them. All in all, I don't recommend the experience.

We returned to the allergy doc to show them I was still alive and to ask if we could leave my car there. They were all glad to see me standing upright. The doc said that anaphylaxis manifests in several ways: hives, difficulty breathing due to swelling in the airway, and a sudden drop in blood pressure. I never had the first two, but had the third in spades. And I didn't have just an anaphylactic reaction, but a severe anaphylactic reaction. Until then I hadn't realized just how bad it was. I am very grateful for the mandatory 30-minute wait after allergy shots. The waiting period was extended from 20 minutes to 30 minutes a while back, and if I had waited only 20 minutes I would have been on the road to the marine lab when the reaction occurred.

Today I am more or less back to normal, except for the Benadryl hangover. It is amazing how quickly the body recovers from such a severe shock like anaphylaxis. I think I'll wait until tomorrow before driving, though. And it remains to be seen what we'll do about continuing the immunotherapy injections. I had been rather cavalier about the whole thing but now will definitely be more conservative and cautious.

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