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The first field trip of the semester for my Ecology class is always a jaunt up the coast to Rancho del Oso and Waddell Beach. It's a great place to start the practice of observing nature, because we can explore the forest in the morning, have lunch, and then wander along the beach in the afternoon. We really are lucky to have such a wide variety of habitats to study around here, which makes taking students out into the field really fun. My passion and expertise will always belong with the marine invertebrates, but it's good for me to work outside my comfort zone and immerse myself in habitats I don't already know very well. During this year's class trip to Waddell Beach I was struck by some things I had seen before but never paid much heed to. And also one very big thing that caught everybody's attention.

Depending on how much rain has fallen recently, Waddell Creek may or may not flow all the way into the ocean. Since California has a short rainy season, there are months when the creek is completely cut off from the ocean, due to both a lack of flow and the accumulation of sand on the beach. So far this rainy season, which began on 1 October 2019, we've gotten about 93% of our normal rain. However, we had a very wet December, and almost no rain since then. I wasn't sure whether or not Waddell would be flowing into the ocean. It was.

Waddell Creek where it flows across the beach into the Pacific Ocean
Waddell Creek flowing into the Pacific Ocean
2020-01-31
© Allison J. Gong

The really big thing that we all stopped to look at was this guy lounging in the creek.

Subadult male elephant seal (Mirounga angustirostris) lying in the creek at Waddell Beach.
Northern elephant seal (Mirounga angustirostris) on Waddell Beach
2020-01-31
© Allison J. Gong

The students had many questions: What was he doing there? Was he sick? Was it a male? Was he dead? Well, no, he wasn't dead. And while I guessed from this view that it was a subadult male, I was secretly relieved to be proved right when we walked down the creek (keeping the mandated distance away from him) and looked back to see his big schnozz.

The elephant seal breeding season is coming to an end, but animals will continue to haul out and rest on the beach. This subadult male clearly isn't going to be dethroning any beachmasters this year, so he has taken the safe route and chosen a beach away from the breeding ground at Año Nuevo, which is ~2 miles up the coast. What I really liked about this particular animal was that we could see the tracks he made getting himself up the beach to the creek.

So that was the big thing. Eye-catching he certainly was, but to my mind not nearly as interesting as the small things we paid more attention to on the beach. It is tempting to think of sandy beaches as relatively lifeless places, compared to something like a rocky intertidal or a redwood forest. But for some reason, this trip I became intrigued by the dune vegetation. At first glance a sand dune seems to be a very inhospitable place for plants, and it is. Sand is unstable and moves around all the time, making it difficult for roots to hang on. Sand also doesn't hold water, so dune vegetation must be able to withstand very dry conditions. It's not surprising that dune plants have some of the same adaptations as desert plants.

Let's start with the natives.

Photograph of yellow sand verbena (Abronia latifolia) at Waddell Beach.
Yellow sand verbena (Abronia latifolia)
2020-01-31
© Allison J. Gong

I love this little sand verbena (Abronia latifolia)! It is native to the west coast of North America, from Santa Barbara County to the Canadian border. It is a sand stabilizer, decreasing the erosion that occurs. The sand verbenas also live in deserts; I saw them at Anza-Borrego and Joshua Tree last year. The beach sand verbena grows low to the ground, probably as a way to shelter from the winds that come screaming down the coast. Cute little plant, isn't it?

The other yellow beach plant we saw was the beach suncup (Camissoniopsis cheiranthifolia), a member of the primrose family.

Photograph of the beach suncup (Camissoniopsis cheiranthifolia) at Waddell Beach.
Beach suncup (Camissoniopsis cheiranthifolia)
2020-01-31
© Allison J. Gong

Like the yellow sand verbena, the beach suncup is a California native. It grows along the entire coast, including the Channel Islands. Also like the yellow sand verbena, the suncup grows low to the ground. Its leaves are thick and a little waxy, to help the plant resist desiccation.

And now for the non-natives. I must admit, I had given very little thought to the plant life on my local beaches. I'd seen and studied beach wrack, but to be honest most of my attention is usually directed towards the water instead of up high on the beach where the plants live. This day I decided to photograph the plants.

This plant is a little succulent called European sea rocket (Cakile maritma). As the common name implies, its native habitat is dunes in Europe, northern Africa, and western Asia.

Photograph of the succulent plant, European sea rocket (Cakile maritima) at Waddell Beach.
European sea rocket (Cakile maritima) at Waddell Beach
2020-01-31
© Allison J. Gong

Cakile maritima has several life history traits that enable it to be carried around the world. It produces a lot of seeds, more so than the native dune plants. The seeds are dispersed by water and can be transported long distances in the ballast water of ships, which is probably how it got to California in the first place. It tolerates disturbances better than native dune vegetation, which allows it to be a superior competitor. Cakile maritima is considered to be invasive, meaning that it can survive and spread on its own in a non-native habitat, but its effects seem to be restricted to beach dunes. Despite its ability to thrive and outcompete our native beach plants, it appears to be unable to expand away from the sand.

Mushrrom, Psathyrella ammophila, growing out of the sand at Waddell Beach.
Psathyrella ammophila at Waddell Beach
2020-01-31
© Allison J. Gong

Our surprise of the day was a beach mushroom! None of us had seen them before. This is Psathyrella ammophila, the beach brittlestem mushroom. Like sea rocket, it is also a European invasive. We were perplexed by this mushroom. Most of a fungus's body (mycelium) is underground. The mycelium spreads through soils as very thin threads called hyphae. Every once in a while the mycelium sends up a fruiting body, which is what we call a mushroom. There is no way to know, from the location of mushrooms, where and how far the mycelium spreads underground.

The presence of a mushroom on the beach means that a fungal mycelium is feeding on something in the sand. There isn't much plant matter buried on beaches, but we hypothesized that perhaps one of the logs from the forest had washed down the creek and been deposited on the beach. It would then be buried in sand, along with all the mycelium it carried, and a mushroom could have sprouted up through the sand.

Well, it was a good hypothesis.

I posted my photo to a mushroom ID page, and it was identified as Psathyrella ammophila. My submission to iNaturalist came back with the same result. A little research led me to another non-native invasive species, Ammophila arenaria, the European marram grass. Notice that the species epithet of the mushroom is the same as the genus name of the plant? That was my first clue. Marram grass is one of the most noxious weed species on the California coast. It was intentionally introduced to the beaches in the mid-1800s, to provide stability to the dunes. It is very good at that, but also spreads very rapidly, usually growing upwards away from the ocean. That said, marram grass also breaks off chunks that can survive in the ocean and float off to colonize new beaches.

The fungus Psathyrella ammophila grows as a saprobe on the decaying roots of Ammophila arenaria. No doubt the fungus was introduced along with the marram grass as an inadvertent hitchhiker. Since there is so much marram grass on our beaches, it's safe to assume that there is a lot of Psathyrella, too. That means it's time to start looking for mushrooms on the beach!

The intertidal sculpins are delightful little fish with lots of personality. They're really fun to watch, if you have the patience to sit still for a while and let them do their thing. A sculpin's best defense is to not be seen, so their first instinct is to freeze where they are. Then, if a perceived threat proves to be truly frightening, they'll scoot off into hiding. They can also change the color of their skin, either to enhance camouflage or communicate with each other.

Around here we have a handful of sculpin species flitting around in our tidepools. Sculpins can be tricky to identify even if you have the fish in hand--many of the meristics (things you count, such as hard spines and soft rays in the dorsal fin, or the number of scales in the lateral line) used to distinguish species actually overlap quite a lot between species. The fishes' ability to change color means that skin coloration isn't a very reliable trait. When I was in grad school there was another student in my department who was studying the intertidal sculpins, and she told me that most of the ones we see commonly are either woolly sculpins (Clinocottus analis) or fluffy sculpins (Oligocottus snyderi). I've developed a sort of gut feeling for the gestalt of these species, but I'm not always 100% certain of my identifications.

Sculpin in a tidepool at Asilomar State Beach. The fish is colored pink and brown, to match its surroundings in the tidepool.
Sculpin at Asilomar State Beach
2019-07-04
© Allison J. Gong

Anyway, back to the camouflaged sculpins. The ability to change the color of the skin means that sculpins can match their backgrounds, which comes in very handy when there isn't anything to hide behind. Since the environment is rarely uniformly colored, sculpins tend to have mottled skin. Some can be banded, looking like Oreo cookies. The fish in this photo lives in a pool with a granite bottom. The rock contains large quartz crystals and is colonized by tufty bits of mostly red algae. There is enough wave surge for these fist-sized rocks to get tumbled about, which prevents larger macroalgae from colonizing them.

Other shallow pools higher up in the intertidal at Asilomar have a different type of rocky bottom. The rocks lining the bottom of these pools are whitish pebbles that are small enough to be tossed up higher onto the beach. I don't know whether or not these pebbles have the same mineral content as the larger rocks lower in the intertidal, but they do have quartz crystals. The pebbles are white. So, as you may have guessed, are the sculpins!

Sculpins on a gravel bottom in a tidepool at Asilomar State Beach. The fish are white and gray in color, to match the color of the gravel in their pool.
Sculpins at Asilomar State Beach
2019-07-04
© Allison J. Gong

Other intertidal locations have different color schemes. On the reef to the south of Davenport Landing Beach, you will see a lot of coralline algae. Some pools are overwhelmingly pink because of these algae. Bossiella sp. is a common coralline alga at this location.

What color do you think the sculpins are in these pools?

Give yourself a congratulatory pat on the back if you said "pink"!

Sculpin in a tidepool at Davenport Landing. The fish is mottled pink and brown, for camouflage among the pink coralline algae in the pool.
Sculpin and coralline algae (Bossiella sp.) at Davenport Landing
2017-06-27
© Allison J. Gong

Sculpins aren't the only animals to blend in with coralline algae. Some crustaceans are remarkably adept at hiding in plain sight by merging into the background. Unlike the various decorator crabs, which tuck bits and pieces of the environment onto their exoskeletons, isopods hide by matching color.

Turning over algae and finding hidden creatures like these is always fun. For example, I saw these isopods at Pescadero this past summer. See how beautifully camouflaged they are?

Sometimes, when you're not looking for anything in particular, you end up finding something really cool. Last weekend I met up with students in the Cabrillo College Natural History Club for a tidepool excursion up at Pigeon Point. We were south of the point at Whaler's Cove, where a staircase makes for comparatively easy access to the intertidal.

Photo of Whaler's Cove just south of Pigeon Point, during an autumn afternoon low tide
Whaler's Cove at Pigeon Point
2019-11-24
©Allison J. Gong

It's fun taking students to the intertidal because I enjoy helping them develop search images for things they've never seen before. There really is so much to see, and most of it goes unnoticed by the casual visitor. Often we are reminded to "reach for the stars," when it is equally important to examine what's going on at the level of your feet. That's the only way you can see things like this chiton:

A chiton (Mopalia muscosa), heavily encrusted with a variety of red algae, at Whaler's Cove.
Mopalia muscosa at Whaler's Cove
2019-11-24
© Allison J. Gong

Mopalia muscosa is one of my favorite chitons. It is pretty common up and down the California coast. However, like most chitons it is not very conspicuous--it tends to be encrusted with algae! This individual is exuberantly covered with coralline and other red algae and has itself become a (slowly) walking bit of intertidal habitat. It is not unusual to see small snails, crustaceans, and worms living among the foliage carried around by a chiton. Other species can carry around some algae, but M. muscosa seems to be the most highly decorated chiton around here. I showed this one to some of the students, who then proceeded to find several others. A search image is a great thing to carry around!

Compared to the rocky intertidal, a sandy habitat can be a difficult place to live. Sand is inherently unstable, getting sloshed to and fro with the tides. Because of this instability there is nothing for holdfasts to grab, so there are many fewer algae for animals to eat and hide in. Most of the life at a sandy beach occurs below the surface of the sand, and is thus invisible to anyone who doesn't want to dig. There's a beach at Whaler's Cove where I've found burrowing olive snails (Olivella biplicata) plowing along just below the surface. I wanted to show them to the students, so I waded in and rooted around. I did find Olivella, but I also found a burrowing shrimp. I think it's a species of Crangon.

Shrimp on sandy bottom of a shallow tidepool at Whaler's Cove. The shrimp is colored to match the sand.
Shrimp (Crangon sp.) at Whaler's Cove
2019-11-24
©Allison J. Gong

Now that is some damn fine camouflage! If the shrimp didn't cast its own shadow, it would be invisible. Even so, it was clearly uneasy sitting on the surface like that. I had only a few seconds to shove the camera in the water and snap a quick photo before the shrimp wriggled its way beneath the sand again.

As I've said before, observation takes practice and patience. To look at something doesn't mean you truly see it. That's why it is so important to slow down and let your attention progress at the pace of the phenomenon you're observing. If the only things that catch your eye are the ones that flit about, then I can guarantee you will never find a chiton in the intertidal. And wouldn't that be a sad thing?

Autumn is migration season in California. We all know that, in the northern hemisphere, birds fly south for the winter and return north for the summer. And indeed, this is a very good time to go bird watching along the Pacific Flyway, as migrating birds stop to rest and feed at places such as Elkhorn Slough. Here in Santa Cruz, autumn is punctuated by the return of monarch butterflies (Danaus plexippus), roosting in eucalyptus trees at Natural Bridges State Beach and Lighthouse Field.

Since 1997 the Xerces Society for Invertebrate Conservation has been tracking monarch sightings on their migrations between the western U.S. and Mexico. They conduct a volunteer butterfly count every Thanksgiving. More recently, community science data sources such as iNaturalist provide much of the information.

Xerces Society Western Monarch Thanksgiving Count. 2019. Western Monarch Thanksgiving Count Data, 1997-2018. Available at www.westernmonarchcount.org.

This morning, before it got warm, I went to Natural Bridges to see how the monarchs were doing. I wanted to photograph clumps of butterflies dripping from tree branches. It seemed, however, that there aren't as many butterflies as I remember from previous years. The clusters were not nearly as large or as dense as they should be. And the data shown in the figure below do demonstrate a precipitous decline in monarch since 2017. We're still a couple of weeks away from this year's Thanksgiving count, and there is still a chance that the butterflies might arrive in larger numbers.

Xerces Society Western Monarch Thanksgiving Count. 2019. Western Monarch Thanksgiving Count Data, 1997-2018. Available at www.westernmonarchcount.org.

Trained observers know how to estimate the number of butterflies in a cluster like this. The numbers of butterflies at various roosting sites are aggregated to assess overall population sizes.

Monarch butterflies (Danaus plexippus) at Natural Bridges
11 November 2019
© Allison J. Gong

This morning I did see one butterfly that had a tagged wing. It was wearing a green Avery round sticker, with some writing in what looks like black Sharpie. The color of the sticker was very close to the green of the surrounding foliage, so I wasn't even able to see the sticker until I downloaded the pictures from the camera.

Monarch butterflies (Danaus plexippus), including one with a green tag, at Natural Bridges
11 November 2019
© Allison J. Gong

At first I thought the tag resulted from an official scientific project or undertaking, but it turns out that anyone can tag a monarch. The tags are used to track migration of the butterflies. There doesn't seem to be a central depository of tags and their origins, so knowing the color of the tag doesn't tell me where this particular butterfly came from.

Once the sun hits the butterflies and they begin to warm up, the clusters start breaking apart. Butterflies open and close their wings, exposing the darker dorsal surfaces to the sun and warming up their flight muscles. Sometimes they dislodge one another.

On a cool morning like this, many of the butterflies that fell out of the clump couldn't fly yet, and landed on the ground. The boardwalk is perhaps not the safest place for a butterfly to wind up, but at least in a monarch sanctuary such as Natural Bridges the visitors are knowledgeable and look out for the butterflies' safety.

Monarch butterfly (Danaus plexippus) on the boardwalk at Natural Bridges
11 November 2019
© Allison J. Gong

As I wrote before, the butterflies we see at Natural Bridges this year were not born here. This means that their survival to this point has depended on healthy conditions in the Pacific Northwest and the western slopes of the Rocky Mountains, where they lived as caterpillars and emerged from their chrysalises. This also means that planting milkweed for monarch caterpillars in California won't help the butterflies that we see here, although it would help butterflies that are destined to overwinter elsewhere. What will help local butterflies--monarchs and otherwise, and all nectar-feeding insects, in fact--is planting California native plants, to provide them with the nutrition they have evolved to survive on.

This time of year is when California earns its nickname as the Golden State. It isn't only the dried vegetation blanketing the hillsides. The light itself takes on a golden hue, especially in the morning and evening when the sun is low on the horizon. Photographers call the time periods just after sunrise and just before sunset the 'golden hour' and with good reason. Some of my favorite photos were taken in either the early morning or late evening.

Today the Elkhorn Slough National Estuarine Research Reserve (ESNERR) held an open house event. Booths were set up on the field outside the visitor center, with information on native plants, research projects taking place at the slough, a watershed demonstration, mosquito abatement tactics, face painting for kids, and even a food truck. I hadn't been to the slough since early summer, and when I got the notice about the open house I decided to spend the morning there. I'd hike around a bit, take some pictures, and do some nature journaling.

It certainly was a beautiful morning. It had been swelteringly hot earlier in the week, and fortunately the heat had lessened. There was a strong cool breeze and the sky was a clear blue.

Railroad tracks near Kirby Park
28 September 2019
© Allison J. Gong

In the spring, when I bring my Ecology students to the slough, the landscape is green. The grasses are green and wildflowers are in bloom. Even the pickleweed looks nice and fresh in the spring. Six months later, however, those same grasses are brittle and brown, and most of the wildflowers have long gone to seed and senesced. The live oaks retain their foliage throughout the year, and after two successive wet winters they are lush and green.

Dried grasses at Elkhorn Slough
28 September 2019
© Allison J. Gong

When I arrived at the reserve this morning I spent a few minutes touching base with acquaintances and meeting some new people, then wandered off on one of the trails. It was a little chilly, very welcome after the previous heatwaves, and I sat on a bench to do some painting and looking around. After about half an hour I heard something behind me that didn't sound like the wind blowing through the grasses. It was much more rhythmic and regular--definitely some critter walking through the brush. Very quietly, I stood up and sneaked around the oak tree to see a group of three or four juvenile wild turkeys disappearing into a thicket.

All in all I had a pretty good two hours of bird watching. I don't consider myself a birder, really. I enjoy watching birds, just like I enjoy watching other animals. The competitive aspect of birding is a real turn-off for me. I don't care about keeping a life list and comparing it to anybody else's. That said, I do like to keep note of what I see at a given time and place, because it helps me understand the natural world a little better. For example, the other day I heard my first golden-crowned sparrow of the season, and although I haven't seen it yet, knowing it is there makes me think that autumn has truly arrived.

In past decades, several different groups of people have been working to restore natural habitat to the slough. One of the earlier ideas was to build artificial islands, hoping they would encourage the marsh plants such as pickleweed to recruit and expand to their former abundance. It didn't really work, but the islands do provide places for resident and migratory birds to stop and rest.

Artificial islands at Elkhorn Slough
28 September 2019
© Allison J. Gong

More recently, a consortium of stakeholders has worked to restore marshlands closer to the ocean. They filled in areas that had been completely flooded, and pickleweed recruited there on its own. That area has been restored to a much more natural condition, with meandering waterways and pickleweed that isn't drowned by seawater. Elkhorn Slough falls into several jurisdictions at the federal, state, and local levels, and getting these groups to work together for a common goal can be difficult. The success that they have had speaks to their willingness to cooperate. I think it helps that any actions taken are based on science, rather than politics or economics.

Over the summer, a lot of work was done to eradicate non-native plant species. This work is ongoing, and may very well never be finished, but it is good to the ecosystem to try. An island called Hummingbird Island has been rid of invasive eucalyptus trees, and now the only trees there are native live oaks and cypress. The trail I hiked went through several areas where trees has been cut down.

Area of Elkhorn Slough where invasive trees have been removed
28 September 2019
© Allison J. Gong

Remember that train I mentioned? Here it is, traveling through the slough at about midday.

The Coast Starlight crossing through Elkhorn Slough
28 September 2019
© Allison J. Gong

Sometimes visitors to the slough don't believe that those tracks are actually used.

Much of the land that the ESNERR sits on used to be a dairy. These barns are, I think, the only dairy buildings that remain. Visitors aren't allowed into Little Barn, but we can walk through Big Barn. It is used for occasional equipment storage and is inhabited by barn owls. Sometimes we find owl pellets on the ground beneath the owl boxes mounted in the barn. It is also not unusual to find pieces of those old-fashioned glass milk bottles near the trails.

Big Barn (background) and Little Barn (foreground) at Elkhorn Slough
28 September 2019
© Allison J. Gong

When I was a little kid I disliked autumn because the shortening days meant that summer was over and winter was coming. As I grow older, though, and gain a presumably more mature outlook on life, I am more able to appreciate the glory of autumn. I still think spring is my favorite season of the year, but autumn in California is indeed golden and lovely.

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We usually think of sea stars as the colorful animals that stick to rocks in the intertidal. You know, animals like Pisaster ochraceus (ochre star) and Patiria miniata (bat star). I see these animals all the time in the intertidal, and if you're a regular reader of this blog you've probably seen the photos that I post here. Given how prominent P. ochraceus and P. miniata can be in the rocky intertidal, it may be a bit of a surprise to learn that not all sea stars live on rocks. In fact, some can't even really stick to a rock.

This morning I was meandering through the Seymour Center when I stopped at a recently refurbished tank. The new inhabitants are a couple of curlfin sole (Pleuronichthyes decurrens) and their secretive and strange roommate. Here's one of the flat fish:

Photo of curlfin sole (Pleuronichthyes decurrens)
Curlfin sole (Pleuronichthyes decurrens) at the Seymour Marine Discovery Center
5 September 2019
© Allison J. Gong

The other fish was hiding up against the wall in one of the back corners and didn't come down until it was feeding time.

The secretive roommate was all but invisible. Here's a photo. Ignore the fish's tail. Do you see anybody else?

Who is this?

Fortunately for all of the tank's inhabitants, feeding time was just around the corner. I knew what would happen, so I stuck my phone on the glass and recorded some video. Keep an eye on the upper left-hand corner. Watching the fish eat is entertaining, too. Just how do they manage with those tiny sideways mouths?

It's not the greatest bit of video, but did you see what happened? That creature emerging from the sand is Astropecten armatus, a sea star that lives in sand. And did you notice how fast it moves? Most of the time it is buried under the sand and usually comes out only to grab food. Every once in a while I'll find it on one of the walls but most of the time it is essentially invisible to human viewers on the other side of the glass.

Astropecten armatus
5 September 2019
© Allison J. Gong

All spread out, this Astropecten is probably a little smaller than my hand. It has a smooth-ish aboral (i.e., top) surface, lacking the spiny protuberances that Pisaster has. The texture of the aboral surface is similar to that of the bat star, Patiria miniata. The species epithet, armatus, means 'armored' and refers to the row of marginal plates along the perimeter of the body. These plates bear a row of spines that point up and another row that point down. Astropecten is unusual among sea stars for having suckerless tube feet. Its tube feet are pointed, and instead of being super grippy, work to push sand around so the animal can sort of bulldoze its way along. As always, form follows function!

Olivella biplicata at Whaler's Cove
3 January 2019
© Allison J. Gong

In the wild, A. armatus lives on sandy flats, rarely exposed even at low tide. One of its favorite prey items is the olive snail, Olivella biplicata. Imagine this life-and-death encounter taking place below the surface of the sand: Olivella is burrowing through the sand, minding its own business and unaware that Astropecten is following the slime trail it (Olivella) left behind. Astropecten catches up to Olivella, shoves a couple of arms into the sand around Olivella, engulfs the snail, and swallows it whole. Eventually an empty Olivella shell is spat out. Incidentally, many small hermit crabs, especially Pagurus hirsutiusculus and juveniles of other Pagurus species, live in Olivella shells. I've often wondered why there are so many empty but intact olive snail shells for the hermit crabs to find, and now suppose that Astropecten's method of feeding might have something to do with it.

Interesting star, this Astropecten. I'm really happy that it is on exhibit again, because even most visitors will never see it, watching it come out to feed is always fun.

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A few weeks ago I was contacted by a woman named Kathleen, who reads this blog and is herself a student of the seaweeds. She said that she studies a site up at Pescadero, about an hour up the coast from me. We decided to meet up during the series of low tides around the Fourth of July so we could explore the area together, and she could help me with my algal IDs. My friend and former student, Lisa, joined us for the fun.

Map of the Pescadero Point region
05 July 2019
© Google

The most prominent landmark along the coastline in this region is Bird Island, which is accessible only at minus tides, when it is revealed to be a peninsula. It smells pretty much as you probably imagine, especially if you happen to be downwind. Given the prevailing wind direction, that means that the closer you get to Bird Island from the south, the stronger the smell. Kathleen's site is the south side of Pescadero Point, fortunately far enough south of Bird Island that the smell isn't noticeable from that distance. She has a permanent transect that she surveys regularly, taking note of algal abundances and distributions.

South side of Pescadero Point
05 July 2019
© Allison J. Gong

One of the notable things we all noticed was the conspicuous presence of big, healthy ochre stars (Pisaster ochraceus)--many hand-sized or larger. I also saw many smaller stars, in the 2 cm size range, but these were hidden in crevices or under algae. The big guys and gals, were out there in plain sight.

Constellation of ochre stars (Pisaster ochraceus) at Pescadero Point
05 July 2019
© Allison J. Gong

However, not all was perfect for the sea stars at Pescadero Point. One of the ochre stars showed symptoms of sea star wasting syndrome (SSWS). It had autotomized two of its arms and had a sloppy, goopy open wound that extended into the oral disc. It was also mushy when I touched it and didn't firm up the way healthy stars do. This star is a goner, even though it doesn't know it yet. That's the beauty (and in this case, tragedy) of an entirely decentralized nervous system.

Sick ochre star (Pisaster ochraceus) at Pescadero Point
05 July 2019
© Allison J. Gong

After I mentioned having seen a sick sea star we compared notes on the current status of SSWS. What more do we know about the syndrome, and any recovery of stars? We came to the consensus that the oubreak was probably caused by a perfect storm of ecological conditions--an opportunistically pathogenic virus that is ubiquitous in the environment, environmental stresses, and high population densities both intertidally and subtidally. Kathleen asked me what I had been seeing recently. I told her that Pisaster ochraceus, one of the species that melted away in spectacular fashion, seems to be making a strong comeback in the places where I used to see it in large numbers. Even though every once in a while i see a sick star, places like Natural Bridges and Davenport Landing are again populated by lots of hand-sized-or-bigger ochre stars. Which of course brings up the question of where these large stars suddenly came from. I think they were tiny stars when the outbreak occurred, hiding in the mussel beds. Many of them died, but as with any plague there are always some survivors. Those lucky few managed to hang on and creep into the niches that opened up when so many adults died. But would little juveniles only a few millimeters in diameter be able to grow to the sizes that we're seeing now, in ~5 years? I suppose that's not out of the question, and we know that when fed well in the lab they grow very quickly, but individual growth rates in the field are difficult to measure.

Another animal goody that we saw were clusters of the bryozoan, Flustrellidra corniculata. Unlike most bryozoans, which are calcified and crunchy, Flustrellidra colonies are soft and flexible. They look more like strange, thick pieces of brown algae than anything recognizable as a bryozoan.

Flustrellidra corniculata at Pescadero Point
05 July 2019
© Allison J. Gong

We were there to do some basic marine botany, and although I kept getting distracted by the invertebrates I did also pay attention to the floral aspect of Kathleen's site. She pointed out that Laminaria sinclairii, one of the small low-intertidal kelps, was always abundant. It's true, there were rocks that were entirely covered with L. sinclairii, like this one:

Laminaria sinclairii at Pescadero Point
05 July 2019
© Allison J. Gong

Laminaria sinclairii and L. setchellii are the most common intertidal species of the genus on our coast. They are easily distinguishable because L. sinclairii has a single undivided blade arising from the stipe, and L. setchellii has a blade that is subdivided into fingerlike sections; in fact, the former species epithet for L. setchellii was dentigera, referring to 'finger'.

Laminaria setchellii at Franklin Point
15 June 2018
© Allison J. Gong

See the difference?

There is a third species of Laminaria on our coast, that I knew only by reputation. What I'd heard is that Laminaria ephemera resembles L. sinclairii except for the morphology of the holdfast: L. ephemera has a discoid, suction-cup holdfast while L. sinclairii has the more typical hapterous holdfast (made of intertwined cylindrical projections). I think I might have seen a few L. ephemera at Pescadero. These thalli appear to have suction-cup holdfasts, don't they?

Laminaria ephemera(?) at Pescadero Point
05 July 2019
© Allison J. Gong
North side of Pescadero Point
05 July 2019
© Allison J. Gong

We didn't spend much time on the south side of the point, but scrambled over the rocks to the north side, where there are stretches of sandy beach between rocky outcrops. Bird Island is that peninsula in the top of the picture. As I mentioned above, it is connected to the beach only at low tide, so while I think of it as a peninsula, it really is an island most of the time.

Once on the north side of the point we slowed down and made some more attentive observations of the flora. It turns out that this portion of our intertidal visit was sponsored by the letter 'P'. One of the things we all noticed was the prevalence of Pyropia, the filmy red alga that is common in the high-mid intertidal. The thallus of Pyropia consists of a single layer of cells connected to form a very thin elastic tissue. It dries to a crisp in the sun, but rehydrates when the tide returns. You've probably encountered Pyropia before without realizing it: nori is made of Pyropia that has been shredded and processed into paper-like sheets, used for things like sushi rolls.

Although it looks uniformly blackish-green when packaged for human consumption, Pyropia's color in life is a glorious iridescent mixture of greens, olives, and purples. It is another of those easily overlooked denizens of the intertidal that deserves a much closer look than it usually gets.

Pyropia sp. at Pescadero Point
05 July 2019
© Allison J. Gong
Plocamium cartilagineum at Pescadero Point
05 July 2019
© Allison J. Gong

Another common red alga at Pescadero Point is the delicate and lacy Plocamium cartilagineum. This is one of the hobbyist phycologist's favorite species because it presses like a dream and makes great gifts or wall decorations. As I wrote about here, Plocamium has a doppelganger: Microcladia coulteri. These algae share a similar morphology, but as I mentioned in the previous post, natural history makes it easy to distinguish between the two in the field. Microcladia is epiphytic, growing on other algae, and Plocamium is not.

Plocamium grows on rock surfaces in the mid-to-low tide regions. It sometimes gets surrounded or even buried in sand, but if you dig down far enough you'll always find the holdfast attached to a rock (or shell or other hard object).

Last month I wrote about Postelsia palmaeformis, the sea palm. We found a most handsome specimen washed up on the beach. Note that, as per usual, it wasn't the holdfast of the kelp that failed. The holdfast did its job perfectly well, and it was the mussel it was attached to that broke free of the rock.

Postelsia palmaeformis at Pescadero Point
05 July 2019
© Allison J. Gong

The sad thing about finding great specimens like this on the beach is the realization that it will soon be dead. In fact, so will the mussel. Such is the price organisms pay for failing to hang onto their substrate (or for their substrate's failure to hang on). The rocky intertidal is a harsh place to live, and can be unforgiving of mistakes and bad decisions.

That's part of the reason I find it so fascinating. Most wild organisms live on the knife-edge of survival, with only the thinnest margin between life and death. Every organism has its predators, pathogens, and parasites to deal with on a daily basis, in addition to the physical stresses of its habitat. All of the organisms that I study in the intertidal are marine--not freshwater or even brackish, although some can tolerate reduced salinity (and on the other extreme, some tolerate very high salinity). They evolved to live in the ocean, in a habitat where the ocean abandons them for a few hours twice a day. Yet as improbable as that sounds, the diversity in the intertidal is astonishingly high. Obviously, for those that can live there, the trade-off between stability and safety is worthwhile. Nature will always find a way.

Be honest now. When you think of clams, what comes to mind? If you're like most people, visions of clams steamed in white wine, garlic, and butter might dance in your head. Or perhaps clams in cioppino or a hearty chowder would be your go-to. In any case, I doubt that clams, as actual living creatures, occupy much of your brain. Because let's face it, at first glance even living clams aren't the most energetic and charismatic animals. Most of the really cool things that they do, like suck water through their shells for filter feeding and gas exchange, they do while buried in the mud.

When you think about it, though, just the fact that clams live in the sand or mud while depending on water that may be quite far from them is rather amazing. All animals require oxygen, and for marine animals that oxygen comes from seawater. Animals that move freely through the water have access to a ready supply of oxygen. But clams live more or less fixed lives encased in sediment, and water can be quite far from their bodies. How, then, do they pull water into their shells and across their gills? They use siphons, which can reach up to the surface of the sediment into the water column.

Siphons of a pholad bivalve at Pleasure Point
16 July 2018
© Allison J. Gong

A clam has two siphons--one pulls clean water into the shells and the other expels water from the shells. This arrangement allows for one-way flow across the gills, which serve double duty as both feeding and gas exchange organs. The siphons themselves are somewhat muscular and can open and close, but it's the ciliary action of the gills that create the actual water current. In a living clam the only visible body parts are the siphons, which in some species (e.g., geoducks) are so large that they cannot be entirely withdrawn into the shells.

Of the two siphons in the picture above, can you tell which is the incurrent and which is the excurrent? What do you think is the functional significance of that network of white structures that cover the opening of one of the siphons?

Not only do clams live buried in sediment, but some of them can actually bore into rocks. These boring clams, the pholads, have shells that are morphologically and functionally different from the typical clams you've encountered in cioppino. They are elongated on the anterior-posterior axis and the anterior ends are heavily sculpted and fortified to grind into rock. Of course, they can do this only in areas where the rock is soft--you don't see pholads burrowed into granite, for example.

Pholad siphons at Pleasure Point
16 July 2018
© Allison J. Gong

Fortunately for the pholads, much of the rock in the Santa Cruz area is a soft mudstone, easily eroded and burrowed into. I've seen pholads at intertidal sites from Capitola to Davenport. Both dead pholads and live pholads can be seen, but it takes a careful eye to spot the live ones. Of course, all you'd ever see of a living pholad is the siphons. When the animal dies, though, the shells are left behind. As the mudstone continues to erode the shells can be exposed, just like fossils. And as a matter of fact, the mudstone formations around here are known for their fossil contents. I think, but am not certain, that these empty shells in holes belong to Parapholus californica.

Pholad shells at Natural Bridges
8 June 2019
© Allison J. Gong

How does a clam burrow into even soft rock? A description of burrowing activity of Parapholus californica can be read here. As you can imagine, it's a slow and continuous process. Fortunately, these clams don't have much else going on and can take their time. In some ways, their lifestyle sounds pretty ideal: hang out in a snug burrow where predators can't get at your soft body and extend your siphons out to bring in clean water for food and oxygen. Sure, when it comes to reproduction the only option available is free-spawning and hoping for the best, but that has proven to be a successful strategy for countless generations of your kind. Aside from the cost of making gametes, it's a pretty low-energy way to produce offspring. Maybe the old saying "happy as a clam" isn't that far off the truth.

4

The annual Snapshot Cal Coast period is scheduled to coincide with the best midsummer low tides, to maximize opportunities for people to get out and blitz the intertidal. The whole idea of Snapshot Cal Coast is to document as much biodiversity as possible, to render a comprehensive account of what our coastal and nearshore biota look like at this moment in time. For someone like me, participating in the various bioblitzes that occur during Snapshot is a good excuse to get up early and play in some of my favorite intertidal sites.

Green surfgrass (Phyllospadix scouleri) and red algae at Pigeon Point
07 June 2019
© Allison J. Gong

We're in the high summer growing season now, and the algae are taking off. Pigeon Point has always been a great spot for seaweed diversity, and I anticipated having a lot much phycological fun when I went there last week. And, very happily, I was not disappointed. There were many animal finds as well, including some nudibranchs that I brought back to the Seymour Center, but the algae were definitely the stars of the show. So I thought I'd show off how beautiful and diverse they are.

The red algae

The vast majority of macroalgae at Pigeon Point are red algae, in the phylum Rhodophyta. Everywhere you look is a sea of rosy pinks, dark purples, and bright or brownish reds, punctuated now and then by a brilliant splash of green which is due to the surfgrass (not an alga!), Phyllospadix. The algae cover all surfaces. They drape into and drift with the water currents. They provide shelter and food for the animals of the intertidal. They make walking a treacherous undertaking--a large part of exploring the intertidal safely is knowing which algae will support your weight and which will dump you on your butt without a moment's hesitation.

At first look, the eye is bombarded with a confounding mélange of reds, dark greens, pinks, and purples. Knowing that they are all in the Rhodophyta doesn't help you make sense of what you are seeing. As usual, what helps is an ability to flip between what I call 'forest' and 'tree' observing: you can spend some time zeroing in on individual specimens and learning or remembering their names, but every once in a while you need to step back and take note of the larger environment where and with whom these species live.

Here's a small forest view to study. How many different red algae can you see?

Red algae at Pigeon Point
07 June 2019
© Allison J. Gong

It's kind of a trick question. A knowledgeable person can probably pick out seven or eight different species. I can distinguish six but can identify only five with any real certainty.

Here's the same photo, with some of the algae labeled for identification:

  • Species A: Prionitis lanceolata
  • Species B: Erythrophyllum delesserioides (my favorite alga!)
  • Species C: either Cryptopleura or Callophyllis
  • Species D: Neogastroclonium subarticulatum
  • Species E: Mazzaella splendens

Just because it's my favorite, and is undeniably beautiful, here's another photo of Erythrophyllum:

Erythrophyllum delesserioides at Pigeon Point
07 June 2019
© Allison J. Gong

To give you some idea of the color and morphological variety in the reds, here's a quartet:

Some of the red algae are epiphytic, living on other algae or plants. Epiphytes are not parasitic and obtain their nutrients from the surrounding water. Although they do not drain nutrients from the alga or plant on which they live, epiphytic algae can occur so densely that they shade their host and deprive it of sunlight. In the intertidal, algae in the genus Microcladia grow as epiphytes. I've seen them most often on other reds, but they'll also live on some of the browns. A while back I wrote about how Microcladia closely resembles another red alga, Plocamium, and how one of the ways to tell them apart is to examine the habitat of each. Microcladia is an epiphyte, and Plocamium grows attached to rocks.

This is Microcladia:

Microcladia coulteri growing on Chondracanthus exasperatus
07 June 2019
© Allison J. Gong

You can see the morphology of M. coulteri a little better here, where it is an epiphyte on host with a smoother texture:

Microcladia coulteri growing on Mazzaella splendens
07 June 2019
© Allison J. Gong

The coralline algae are a subset of the red algae. They have a different texture from the other reds, because they deposit calcium carbonate within their cell walls. Corallines can grow as encrusting sheets over surfaces, or have upright branching forms. They are often epizoic (living on animals) or epiphytic.

The brown algae

The brown algae (Phylum Ochrophyta) are not as diverse as the reds, but can be locally abundant. The browns come into their own in the subtidal, where they form the physical structure of California's famous kelp forests. Even in the intertidal they can be among the most conspicuous of the algal flora.

Egregia menziesii, the so-called feather boa kelp, is very common on our coast. It has tough, strap-like stipes that can be 3-4 meters long and a large conical holdfast, so it is pretty conspicuous. Egregia is the most desiccation-tolerant of the kelps around here; it grows as high as the mid-intertidal. The specimen in the photo below looks a little ragged at the ends, which makes me think it might be a holdover from last year.

Egregia menziesii at Pigeon Point
07 June 2019
© Allison J. Gong

I've seen Egregia at every rocky intertidal site so far. Other brown algae are more particular about where they live. Dictyoneurum californicum, for example, is a brown alga that lives only in areas that get a lot of water movement. It is seasonally abundant at Pigeon Point, where it is a low intertidal resident, but I don't see it at more sheltered locations such as Davenport or Natural Bridges. This year D. californicum is at Pigeon Point, although not in large patches as it was a few years ago. As the blades mature, they develop a split in the basal region just distal to the short stipe. The blades themselves feel crunchy and brittle.

Dictyoneurum californicum at Pigeon Point
07 June 2019
© Allison J. Gong

All that said, the most remarkable brown alga at Pigeon Point has got to be Postelsia palmaeformis, the sea palm.

Rocky outcrop at Pigeon Point
07 June 2019
© Allison J. Gong

Postelsia is restricted to the most exposed rocky outcrops, where they bear the full force of the bashing waves as the tide rises and falls. They stick up defiantly above the surrounding topography, as if daring the waves to do their worst.

Postelsia palmaeformis at Pigeon Point
07 June 2019
© Allison J. Gong

Sea palms grow to a height of about half a meter, and are usually the tallest things where they live. They typically occur in small clusters. They do resemble miniature palm trees, don't they? It's the thick, very flexible stipe that allows them to live where they do. When the waves come crashing down, the stipe simply bends with the force of the water, and then pops back up after the wave recedes. This hardiness doesn't make the thalli invincible, though. After winter storms blow through, you can often see Postelsia washed up on the beach.

Postelsia palmaeformis at Pigeon Point
07 June 2019
© Allison J. Gong

You might think that Postelsia gets ripped off rocks by strong waves, but you'd be wrong. The holdfast for these algae is surprisingly tough and good at doing its job. When you see Postelsia stranded on the beach, you'll usually find that it wasn't the holdfast that gave way--most likely the rock or mussel it was attached to will have been torn off along with the sea palm. That's pretty impressive! Of course, any sea palm washed up on the beach is a dead sea palm, so in that sense it doesn't matter whether it was the alga or the substrate that failed. But given the forces that these algae withstand on a daily basis, it's remarkable how well they manage to hang on in the high energy environment where they thrive.

Algae don't get a lot of love, even among marine biologists. If I think there are not many people who study the invertebrates, there are even fewer who study seaweeds. Some organisms have an easier time attracting the attention of human beings, and among macroscopic organisms the invertebrates and algae are probably tied for the bottom ranking. It amazes me that visitors to the seashore can look over a place like Pigeon Point and not see anything. I suppose it's a matter of getting lost in the forest and forgetting that it is made up of trees, or not even recognizing that it is a forest. In the intertidal the 'trees' are at foot level so it does take some work to figure out what's going on. Like most worthy endeavors, though, the effort is well rewarded.

Professor Emeritus John Pearse has been monitoring intertidal areas in the Monterey Bay region since the early 1970s. Here on the north end of Monterey Bay, he set up two research sites: Opal Cliffs in 1972 and Soquel Point in 1970. These sites are separated by about 975 meters (3200 feet) as the gull flies. My understanding is that the original motivation for studying these sites was to compare the biota at Soquel Point, which had a sewage outfall at the time, with that at Opal Cliffs, which did not. The sewer discharge was relocated in 1976, and the project has now morphed into a study of long-term recovery at the two sites. In the decades since, John has led students, former students, and community members to conduct Critter Counts at these sites during one of the mid-year low tides. Soquel Point is visited on the first day, and Opal Cliffs is visited the following day. When John founded the LiMPETS rocky intertidal monitoring program for teachers and students in the 1990s, the Soquel Point and Opal Cliffs locations were incorporated into the LiMPETS regime.

Soquel Point and Opal Cliffs sampling sites
© Google

I have participated in the annual Critter Counts off and on through the years--around here, one takes any chance one gets to venture into the intertidal with John Pearse! I usually have my own plans for this series of low tides, but try to make at least one of the Critter Count mornings. This year (2019) the first 16 days of June have been designated the official time frame for Snapshot Cal Coast, giving marine biologists and marine aficionados an excuse to go to the ocean and make observations for iNaturalist. I had set myself the goal of submitting observations for every day of Snapshot Cal Coast, knowing that every day this week would be devoted to morning low tides. That's the easy part. Next week, when we lose the minus tides, I'll do other things, like look at plankton or photograph seabirds. My plans for this week included a trip to Franklin Point on Wednesday and doing the Critter Count at Opal Cliffs on Thursday. John asked me if I could also do the Wednesday Critter Count. As I alluded above, I'm not going to say "No" to an invitation like that! So I didn't make it out to Franklin Point to document the staurozoans for Snapshot Cal Coast, but that's okay. Some plans are meant to be changed.

Day 1- Soquel Point

Both the Soquel Point and Opal Cliffs sites are flat benches with little vertical topography. The benches are separated by channels that retain water as the tide recedes. The Soquel Point site has deeper channels that make the benches more like islands than connected platforms.

Intertidal benches at Soquel Point
2019-06-05
© Allison J. Gong

The benches are pretty easy to get around on, as long as you remember that surfgrass (Phyllospadix spp.) is treacherous stuff. The long leaves are slippery and tend to cover pitfalls like unexpected deepish holes. The difficulty at this site is that it takes very little rise in the tide for water in the channels to get deep. You can be working along for a while, then get up to leave and realize that you're surrounded by water. Keeping that caveat in mind, we worked fast.

My partner for the morning, Linda, examines a quadrat at Soquel Point
2019-06-05
© Allison J. Gong

For the Critter Count we keep tabs on only a subset of the organisms in the intertidal. The quadrat defines our sample; we put it down at randomly determined coordinates within a permanent study area. Some animals, such as anemones, turban snails, and hermit crabs, are counted individually. For other organisms (surfgrass, algae, Phragmatopoma) we count how many of the 25 small squares they appear in. Some quadrats are pretty easy and take little time; others, such as ones that are placed over channels or pools, are more difficult and take much longer.

Because of the rising tide I didn't have a lot of time to look around and take photos of the critters we were counting. Linda and I were worried about finishing our quadrats before the channels got deep enough to flood our boots. But here are two of the things that caught my eye:

Anthopleura sola at Soquel Point
2019-06-05
© Allison J. Gong
Sea lettuce (Ulva sp.) and anemones (Anthopleura sola) at Soquel Point
2019-06-05
© Allison J. Gong

Day 2 - Opal Cliffs

Opal Cliffs intertidal area
2019-06-06
© Allison J. Gong
Lizzy counts critters in our quadrat
2019-06-06
© Allison J. Gong

The next day we met a half hour later and a few blocks down the road. The Opal Cliffs site is a popular spot with surfers: If you've ever heard of the surf spot Pleasure Point or seen the movie Chasing Mavericks, you know about this location. As far as the intertidal goes, it's an easy site to study. The channels aren't as deep as those at Soquel Point so we could work at a more leisurely pace. As the rest of the group hauled up all the gear and left to get on with their day, I stayed behind to take pictures for my iNaturalist observations. The sky was overcast, making for good picture-taking conditions. I'll just add a gallery of photos to share with you.

There is one critter that deserve more attention here, because I'd never seen one in the intertidal before. Two of the guys finished their quadrats early and started flipping over rocks to look for an octopus. To my knowledge they didn't find any octopuses, but they did find a bizarre fish. At first it didn't look like much:

Fish under rock at Opal Cliffs
2019-06-06
© Allison J. Gong

Hannah, the LiMPETS coordinator for Monterey and Santa Cruz Counties, recognized the fish right away and grabbed it by the body. She held it up so we could see the ventral surface.

Plainfin midshipman (Porichthys notatus) at Opal Cliffs
2019-06-06
© Allison J. Gong

This is a plainfin midshipman. These are nearshore fish found in the Eastern Pacific from Alaska to southern Baja. Clearly, I need to spend more time flipping over big rocks! The midshipman is a noctural fish, resting in the sand during the day and venturing out to feed at night. Like many nocturnal animals, it is bioluminescent--those white dots on the fish's belly in the photo above are photophores. Midshipmen are heavily decorated with photophores all over the body. This bioluminescence is used both for predator avoidance and mate choice.

The lives of plainfin midshipmen and human beings intersect in the wee hours of the morning. During breeding season these fish sing or grunt. They breed in intertidal areas, where females lay eggs in nests that are subsequently guarded by males. Both sexes make noise, but it's the breeding males that are the noisiest. They grunt and growl at each other when fighting for territory, but hum when courting females. Females typically grunt only when in conflict with others. People who live in houseboats on the water in Sausalito have reported strange sounds emanating from the water beneath them, only to learn that what they hear are the love and fight songs of fish!

I've always been a fan of the intertidal fishes. They seem to have a lot of personality. Plus, any aquatic animal that lives where the water could dry up once or twice a day deserves my admiration. Of course, all of the invertebrates also fall into this category, which may explain why I find them so fascinating.

After we admired the midshipman's photophores and impressive teeth, we put it back in the sand and replaced the rock on top of it. It was probably happy to get back to snoozing away the next few hours before the tide returned. I don't know how I never realized the midshipmen were in the intertidal. I think I just assumed that they were in deeper water. Now that I know where to find them, I will spend more time flipping over rocks. And who knows, maybe I'll even find an octopus!

2

In my experience, the most difficult organisms to photograph in the wild are staurozoans. Even birds in flight are easier. The problem with staurozoans is where they live. I never see them in calm, still pools, where taking pictures would be easy. Instead, they seem to like surge channels where the water constantly sloshes back and forth, and even in the few seconds between a wave coming in and receding they never really stop moving. Their bodies are extremely soft and squishy, so the slightest current causes them to flutter and make blurry photos. When they are emersed their bodies don't really look like anything except a soggy booger, so they aren't recognizable as staurozoans unless they are underwater. And when underwater they don't hold still, and so on and so forth.

Still, finding them is always a treat, even if I can't capture photographic proof. They really are extremely gorgeous creatures.

Staurozoan (Haliclystus 'sanjuanensis') at Franklin Point
2019-05-08
© Allison J. Gong

They are also enigmatic creatures. Much of staurozoan biology, including their evolutionary relationships, remains poorly understood. Until recently the staurozoans were considered a subgroup of the Scyphozoa, the taxon that includes the large medusae such as moon jellies (Aurelia spp.) and sea nettles (Chrysaora spp.). However, using data from more extensive morphological and molecular studies, most taxonomists now agree that the Staurozoa should be elevated to a level equivalent to the Scyphozoa. In other words, the staurozoan lineage probably evolved alongside, but separate from, the scyphozoan lineage.

Whatever their evolutionary history and relationships, what we know about staurozoans is very limited. They are considered to be stalked jellies (hence their previously assumed close affinity to the scyphozoans) that do not have a separate polyp stage. Their bodies consist of an adhesive peduncle, or stalk, that attaches to algae or surfgrasses, and a calyx or goblet-shaped portion surrounded by eight tapering arms. Each of the eight arms is topped with a puffball of stinging tentaches which are uses to catch food and presumably to defend the animal against predators. The mouth is located in the center of the calyx, usually lifted up on a short stalk called a manubrium. The animal feeds by capturing prey on the tentacles and flexing the arm so the food is brought to the mouth. Staurozoans are not permanently attached and can sort of 'walk' with a somersault-like motion, flipping end-over-end.

Staurozoan (Haliclystus 'sanjuanensis') at Franklin Point
2019-05-08
© Allison J. Gong
Haliclystus 'sanjuanensis' at Franklin Point
2019-05-08
© Allison J. Gong

Haliclystus 'sanjuanensis' at Franklin Point grows to a length and diameter of ~3 cm, although most of the ones that I see are smaller than that. The most common color is this reddish brown, but I've also seen them in a gorgeous bottle green that makes them much easier to see against the background of their habitat. I usually see them attached to pieces of red algae, but I'm not sure they actually prefer red algae to either green or brown algae. I don't think I've ever seen one attached to a rock.

Last week I had one of those moments in the intertidal when I felt something stuck on my finger and I couldn't get rid of it. That happens frequently, with small bits of algae getting caught on everything; usually I just flick my hand and they go flying off. But this thing wouldn't leave. I finally stuck my hand in the water to rinse it off, and saw that I had been glommed onto by a small staurozoan!

Staurozoan (Haliclystus 'sanjuanensis') on my finger at Franklin Point
2019-05-08
© Allison J. Gong

See how the animal stuck to me with its tentacles, while its peduncle is still attached to a piece of Ulva?

As I mentioned, not much is known about these strange animals. They possess the stinging cells to prove their inclusion within the Cnidaria, but are aberrant medusae which stick to algae instead of swimming around in the water column. Their life cycle is more or less cnidarian-like, but their planula is non-ciliated. Their ecological relationships haven't really been studied at all.

Which is why this photograph is so informative. It's not a great picture, by any means, but it shows a glimpse of how staurozoans interact with other species.

2019-05-08
© Allison J. Gong

This is a picture of two animals, a staurozoan (H. 'sanjuanensis') and a nudibranch (Hermissenda opalescens). Both of these animals are predators. Hermissenda is well known for its affinity for general cnidarian prey, from which it steals the stinging cells to defend its own body (a behavior known as kleptocnidae). But the staurozoan should be quite capable of defending itself. So, who is doing the eating, and who is being eaten?

Given the dastardly nature of Hermissenda, I'd bet on it as the eater. Those damned nudibranchs have to spoil everything! The staurozoan will probably sustain damage, perhaps losing a tuft of tentacles, but should be able to regrow the lost parts. And the sting of the staurozoan may keep the nudibranch from eating as much as it would like. That's the thing. We just don't know.

I'll definitely be keeping an eye out for the staurozoans at Franklin Point the rest of this tide season. I may even bring a few back to the lab for closer inspection; my collecting permit allows me to do so. I could then photograph them under controlled conditions and hopefully get some better pictures. I find these animals very intriguing, being both so clearly cnidarian-like and simultaneously so inscrutable. I always did like a good mystery story!

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