When the sun shines ...

Two days of sunshine. No wind. And a low tide. It's been a while since I've been out on the tide flats. And there were birds, critters, seaweeds, rocks (so many rocks!); I've got a bunch of photos to process.

For today, here are some anemones, pink, green, beige. All were at the upper level of the beach, most barely underwater; they keep on fishing as long as the water covers their tentacles.

Pink-tipped green anemones, Anthopleura elegantissima. With barnacles, shredded seaweeds and eelgrass.

Burrowing or Moonglow anemones, Anthopleura artemisia. The green colour shows the presence of a green alga.

More Pink-tipped greens. With a blade of sea lettuce,

The tide has just left this one stranded; it will soon shrink down underneath the sand. Bits of broken shells stick to the base. Looks like a doughnut with sprinkles, doesn't it? 

The orange and white things on the left are Dwarf Calcareous tubeworms, Pileolaria spp. Also present: mussels, periwinkle snails and another pink-tipped anemone. Broken bits of shell collect on the sand near the top of the intertidal zone; lower down, the water washes them away.

More critters tomorrow, I think.

~~~~~~~~~~~~~

Salió el sol. Dos dias hace que no ha llovido, y no hubo nada de viento. Y la marea estaba baja en la tarde. Hace tiempo que no he podido caminar en la zona intermareal. Y había pájaros, animalitos, hierbas marinas, piedras (¡tantas piedras!) Ahora tengo un montón de fotos para procesar.

Por ahora, aquí hay algunas anémonas, color de rosa, verdes, café claro. Todas están en la aona superior intermareal; casi todas apenas cubiertas de agua. Siguen buscando alimento mientras el agua les cubre  los tentáculos.

1. Anémonas verdes con tentáculos color de rosa, Anthopleura elegantissima. Con bálanos y fragmentos de hierbas y algas marinas.
2. Estas son anémonas verdes, que llamamos "Resplandor de Luna", Anthopleura artemisia. El color verde se debe a la presencia de alga en los tentáculos.
3. A. elegantissima. Con una hoja de lechuga marina.
4. La marea acaba de dejar esta anémona fuera del agua. Pronto se esconderá bajo la arena. Pedacitos de concha se adhieren a la base. Parece una "dona con sprinkles", ¿no?
5. Las criaturitas anaranjadas con blanco son gusanos de tubo calcáreo, Pileolaria spp. Aquí también hay mejillones, caracoles marinos Littorina sitkana, y otra anémona A. elegantissima. En la parte superior de la zona intermareal se amontonas pedacitos de concha; más abajo, el agua se los lleva.

Para mañana, otras criaturas intermareales.

Painted, plumose, purple. Pizza?

Leaving Paradise Meadows, moving on. Our gallivanting took us to Brown's Bay. As always, I had to go first to see what was happening in the water below the wharf. On the blue plastic floats:

A painted anemone, Urticina crassicornis.

Another painted anemone, and kelp.

Mystery patch

I don't know what this round "underwater pizza" is. It doesn't help that the light was so bright, shining down through the water, that all the edges have rainbows. On the upper left, green algae cover either sea urchins or more anemones.

A narrow-ribbed kelp. Maybe Alaria marginata.

Kelp-encrusdting bryozoan patches on brown kelp. And a few limpets.

And on the rocks near the shore under a metre of incoming tide:

Purple starfish, Pisaster ochraceus. With a hermit crab for company.

Next: a few swimmers.

~~~~~~~~~~~~

En un dia caluroso, con el sol tan deslumbrante que me dejaba casi ciega, llegamos a Brown's Bay. Lo primero que hicimos, como siempre, fue ir a investigar lo que pasaba en el agua debajo de los muelles. En los flotadores de plástico azul, vimos:

1. Una anémona "pintada", Urticina crassicornis.
2. Otra anémona pintada, con quelpo.
3. No sé que cosa es esto; tal vez algo que se perdió, con criaturas nuevas creciendo en su lugar. Es difícil ver, también por la luz tan brillante que hace que todo esté rodeado de arcos iris. A la izquierda, unas hojas de alga verde cubren tal vez un erizo de mar.
4. Quelpo. Creo que es Alaria marginata.
5. Y otro tipo de quelpo, con sus colonias del briozoo Membranipora serilamella. Y unas lapas.
6. Y en la playa, bajo un metro de la marea que venía subiendo, una estrella de mar, Pisastre ochraceus. Con un pequeño cangrejo ermitaño.

Mañana; pescaditos y medusas.

Do they get overtime pay?

 Anemones at low tide. When the water recedes, they shrink into themselves, becoming greenish circles in the sand or soft lumps on the side of a rock. But between the rocks, where the sand dips and a few inches of water still cover them, they stay open and feeding. Do they grow bigger in these spots, or reproduce more enthusiastically? I wonder.

Pink-tipped green anemone, Anthopleura elegantissima, very pale, with bubbles.

Burrowing anemone, Anthopleura artemisia. With red feathery seaweed, with bleached tips.

This burrowing anemone has been eating mussels.

A small family grouping. "Colonies of clones actually war against each other." (Marine Life PNW)

Next: colonies on dry rock, waiting out the low tide.

~~~~~~~~~~~~~~

Unas anémonas, vistas durante la marea baja. Normalmente, cuando el agua desaparece, las anémonas se encogen, haciéndose apenas unos circulitos entre la arena, o cojines suaves en los lados protegidos de las rocas. Pero entre las rocas, en los espacios donde las corrientes hacen pocitos en la arena, y el agua sigue cubriéndolas, se quedan abiertas, comiendo. ¿Será que aquí crecen más, o se reproducen más rapidamente?

Fotos: 

1. Una anémona verde con las puntas color de rosa; ésta es muy pálida. Anthopleura elegantissima.
2. Una anémona verde, Anthopleura artemisia. Con un alga marina roja, pero con las ramitas blanqueadas por el sol.
3. Otra anémona verde; este ha estado comiendo mejillones.
4. Un grupo familiar. "Las colonias compuestas de clones hasta llegan a hacer guerra contra otras." (De la enciclopedia Marine Life PNW)

Mañana; otras colonias situadas en roca donde la marea baja las deja en seco.

A few anemones

The tide was low. And it was still daylight. And it wasn't raining! I had a chance to do a bit of tidepooling. I found these anemones, still wet, still exposing their tentacles.

Bright green colour, stripped tentacles. Burrowing anemone, Anthopleura artemisia.

The big anemone in my tank is one of these, but much paler; sunlight feeds the green algae that these anemones harbour in their tentacles and oral disc. The algae converts sunlight to sugars, feeding both itself and the anemone.

Another burrowing anemone; this one has a bit of orange pigment.

And a few inches away, this peach-coloured anemone is open for business under an inch of water. I'm not sure of the species.

And while I'm at it, here's my plumose anemone, at home in the tank.

"Metty"; Metridium senile, happily reaching out to the light.

~~~~~~~~~~~~~~~~~~~~

La marea estaba baja. Y los dias son más largos ahora; todavía había luz. ¡Y no estaba lloviendo! Pude pasar unas horas buscando entre pozas de marea. Encontré estas anémonas, apenas fuera del alcance de las olas, todavía mojadas, todavía con los tentáculos abiertos.

La primera es una anémona de las que llamamos "excavadoras", la Anthopleura artemisia, de un color verde fuerte y con las rayitas blancas en los tentáculos.

La anémona grande que vive en mi acuario es de esta especie, pero está mucho más pálida. Estas anémonas contienen algas verdes, viviendo en sus tentáculos y la superfice alrededor de la boca; estas contienen clorofilo y con la luz del sol producen azúcares que comparten con la anémona. La que vive en mi casa no recibe tanta luz del sol.

La segunda foto es de otra de la misma especie, pero con un poco de pigmento anaranjado.

La tercera es una anémona anaranjada; no sé a cual especie pertenece. Está totalmente abierta, ya que la cubre una pulgada de agua.

Y ya que estoy mirando anémonas, la cuarta foto es de mi anémona emplumada, Metridium senile, en mi tanque.

Under the water line

 The wharf, on the sunny side, is a quiet place, a watery parking lot. There are a few people, gulls, a dog or two, maybe even a cat. Sometimes a heron.

But on the underside; that's another story. There's more busy and crowded biodiversity there than in the entire city of Ankh-Morpork*.

Plumose anemones, sponges and much more, on the side of a float.

At first glance, this is a mess. Too much going on; too crowded, too many shapes. So I've added labels to the photo. It might be a good idea to click on it to bring it up to full size.

There's even a nudibranch!

Another anemone, same species, with friends.

And here it is, with labels. Help me out here!

And another photo, from a wharf edge in full sun:

A few barnacles grow above the water line, in the splash zone.

And here it is, labelled:

The worms like the dark better.

Summing up: there are anemones, sponges, tunicates, barnacles and mussels and limpets, assorted feather duster worms, at least one nudibranch, a sea urchin, hydroids, assorted algae. Present, but not visible, are a full contingent of amphipods, copepods, assorted worms out of tubes, assorted worms in tubes, snails, bryozoans, probably some isopods, maybe a few shrimp. The usual crabs are not the one here, which I think, seeing only the underside, is probably a shore crab; the usual crabs are kelp crabs, longer-legged for crawling on floaters, and an olive-green colour which makes them hard to see. 

But there is still more! I'll upload a few more photos tomorrow.

*Which includes trolls, dwarfs, golems, werewolves, vampires, banshees, gnolls, gnomes, Wee Free Men, zombies, talking dogs, ditto ravens, gargoyles, elves, goblins, orcs, Death, incarnated auditors, the 5 horsemen, bogeymen, and humans, just taking into account the "intelligent" (although not necessarily wise) species. And not counting the yeti, who is wise enough to stay up in the snows.

~~~~~~~~~~~~~~

En el muelle, todo es tranquilo; al fin es un estacionamiento, aunque sea sobre agua. Hay algunas personas, gaviotas, uno que otro perro, tal vez hasta un gatito. Y a veces una garza.

Abajo del agua, ya es otra cosa. Hay un ecosistema tan diverso, tan lleno, que es difícil verlo o describirlo.

En estas fotos, tomadas al lado de dos flotadores, hay: anémonas, esponjas, un nudibranquio, cientos (aunque solo se ven algunos) de anélidos, uricordados (tunicados), lapas, mejillones, cirrípedos, hidroides, y un cangrejo. Y muchas algas, rojas y verdes, que se intermezclan con los anélidos que viven en tubos y, abiertos, se confunden con los hilitos de alga.

Hay mas animales aquí que no se pueden ver, pero por cierto están escondidos bajo el alga: anfipodos, copepodos, más anélidos, briozoos, caracoles, probablemente unos isopodos, y camarones. Los cangrejos que veo a seguido no son como el que aparece en la foto, un cangrejo que más bien se halla entre las piedras en la playa, pero un cangrejo "kelp" que tiene las patas larguísimas para mejor agarrarse a los flotadores, y de un color verde oliva, que lo hace muy difícil de ver entre el alga.

¡Hay más! Subo más fotos mañana.

Busy scene

(Text in Spanish at the bottom: el texto en español sigue al pie de la página.)

The little periwinkle snails are hard workers. They scrape away the algae from the walls, from the oyster shells, from the eelgrass, and the filter intake. Here's one cleaning up the shell of a young hermit crab.

Hairy hermit, Pagurus hirsutiusculus, still very small. They lose their orange colour as they grow. 

Most of my crabs are quite small, but there's one huge one (huge by shore crab standards anyhow). His pincers are wide and powerful. The snail shell above, on the right shows what he can do; he breaks the shell of a live snail to get at the meat. He is otherwise not aggressive; everybody else gets out of his way; nobody challenges him.

But  nothing goes to waste. An orange-striped green anemone has set up shop in the abandoned snail shell.

Plumose anemone, Metridium senile, surrounded by seaweeds (Pacific rose, Turkish towel, eelgrass, a fragment of sea lettuce) and broken shells. 

~~~~~~~~~~~~~~

Los caracolillos trabajan constantemente. Raspan el algae de la pared, de las conchas en el piso, de las algas marinas, y hasta de la tubería del filtro. Aquí en la primera foto, uno se ocupa limpiando la concha usada por un cangrejito ermitaño.

El beneficiario es un ermitaño peludo, Pagurus hirsutiusculus, todavía muy joven. Al crecer, pierden el color anaranjado.

La mayoría de mis cangrejos son pequeños, pero uno es grande, enorme según el tamaño normal de su especie, Hemigrapsus oregonensis. Sus pinzas son grandes y fuertes. En la foto del cangrejo ermitaño, la conchita rota al lado derecho sirve como muestra de su actividad. Con las pinzas, aprieta la concha de mar hasta romperla, para comerse la carne.

Aparte de eso, no molesta a los demás habitantes del aquario; nadie le hace frente.

En el agua, nada se desperdicia. Una anémona (Diadumene lineata) se ha instalado en la concha rota donde está protegida pero expuesta a la corriente que le trae sus alimentos.

En la segunda foto aparece la anémona emplumada (Metridium senile) rodeada de algas marítimas: rosa pacífica, toalla turka, lechuga marina, y una hoja de Zostera marina.

Aquarium update

Surprising happenings in my aquarium! Up until a few months ago, almost every time I changed the water in the tank, I removed everything so that I could scrub the walls without scratching them or upsetting the residents. The hermit crabs and crabs went in one dishpan, the snails in a yogurt container, the barnacles and shells with anemones attached in another, seaweeds and eelgrass in a bucket, and so on. While they were there, I fed the hermits, checked over everything for problems, weeded out dying seaweed.

And, putting everything back, I counted. At last count, there were 40 hermits, most of them tiny. And 4 crabs. A varying number of snails; up to 70, down to about 40 (the big anemones eat them and I go to the beach for more.)

Orange-striped green anemones in old barnacle shells.

After the debacle with poisoned water this winter, I'd not been able to find a reliable source of water, so instead of bringing in new every couple of weeks, I've been cleaning and changing the filters a couple of times a week, adding fresh, filtered water as needed to bring down the salinity. I've scrubbed the walls and weeded, but without emptying the tank; it all takes time. So I haven't been counting my resident population.

Pink-tipped green anemone with her baby (clone) in an old moon snail shell.

The water situation improved. I found a source of safe water, and cleaned out the tank. And counted the hermits and shore crabs. I expected to have lost a few over the winter; nothing lives forever. But when I counted (three times, to be sure) there were 43 hermits, and still the 4 crabs, full-grown now. The tiny hermits were bigger now; I didn't see any pinhead-sized ones. But they were all there. Amazing!

A couple of the crabs were carrying young. They took good care of their brood, but of course, it was all a waste, wasn't it?

Out in the wide ocean, the baby crabs (zoea and then megalops) are microscopic free-swimmers that become part of the plankton, the base of the food chain that feeds invertebrates, fish, birds, and ultimately us. Life is precarious out there; everything is looking for a tasty bit of wriggly meat. Ma crab has released thousands of zoea; only a very few will survive.

In my tank, predators are few. The oysters, the anemones, the worms; that's about it. Except for one big, starving, insatiable predator: the pump and its filters. It sucks in seaweed fragments, incautious amphipods, copepods, and of course, all the crab and hermit crab babies. I never expect any native-born youngsters in the aquarium; the filters eat them.

Oyster lips and orange-striped green anemones

So I never expected this. I was watching a young hermit, when I saw a crab-like movement underneath an old shell. Crab-like, but too small. I had to get out my hand lens to look at it. And it was a crab! A Baby Crab! Tiny, tiny, really tiny; a new pre-adult, apparently grown from scratch in my tank!

And now, checking carefully under stones and shells, I found two more, one about 4 mm. across, the other a whole cm. across.

The second smallest. Very shy, running away from my and my camera. His "carpet" is a shard of broken abalone shell.

Over the winter, I've brought home a couple of handfuls of eelgrass and rockweed, a blade or two of red algae: it hasn't been a good winter (or spring) for fresh beach veggies. I always check this over very carefully, looking to see what live things have hitchhiked. There were a few tiny periwinkle snails, no hermits, an amphipod or two, and no crabs. And a damaged jellyfish last week, which the crabs ate. That's it.

So maybe, just maybe, those extra three hermits are also home-grown, not three pinhead hermits I'd missed before.

In a snowy underwater jungle

Every few days I pull up a stool and aim the camera at the community in my little aquarium. Yesterday, I took over 100 shots; two were usable, with a possible third to be processed. Par for the course.

I love it when one hermit goes for a walk on a blade of eelgrass, above the jungle below.

Small hermit, running, on waving eelgrass, halfway across the tank, but near the light. And the water is nearly clear up here. Auto lighting, auto noise filter. Piece of cake!

Most of the crab and hermit crab activity, however, goes on down on the floor, amid scraps of seaweeds, worms, copepods, amphipods, snails, waving antennae, limpet poop, dancing sand grains, rolling stones, broken shells, waving anemone and barnacle tentacles.

And algae. Algae covers everything, including the glass I'm shooting through. No matter how I scrub it, there's always some there, caught in the scratches on the glass. The hermits and crabs are responsible for these scratches; they're always banging about with the sharp edges of their shells, or piling up sand against the glass, and then scraping it away, or trying to climb the unclimbable.

And the water is full of blowing "snow", the crumbs of food tossed out by the crabs, (messy eaters), copepods and air bubbles, bits of torn seaweed, shreds of discarded hermit molts, more limpet poop, oyster spits, more fragments of algae. The crabs and hermits are happy in clear water, but the anemones (orange-striped green, burrowing, pink-tipped green, and plumose in this tank) love this nutritious snow soup.

The camera doesn't. I can train my eye not to see it, but the camera notices every little copepod antenna and every rotting spot on the seaweed.

So here's a hermit (and a bit of a second hermit) in her usual habitat, just the way she likes it, the way I would find their community on the shore (except there, if I get down to their level, they all up and leave):

Grainy hand hermit, Pagurus granosimanus, with a shell she's rolling around. It's too small for a new outfit, so maybe she's just playing. She has lost most of one red antenna; probably in an argument over a scrap of food.

I had to clean up the background, delete quite a bit of glass algae and a blurry anemone, and adjust the light just to make the hermit visible in the mess. Imagine algae spots and swimming tinies all over.

Down in the left corner is a swarm of copepods. The snail shell at the right is vacant; soon one of the growing hermits will claim it. Some of the limpet poop is visible to the right of that blue stone.

The seaweeds are green sea lettuce, well used, a dark red blade algae, some holey kelp blades; the hermits have been chomping on this all week. The yellow edges are where the red algae is dead and flaking off. I could remove this, for the look of it, but the hermits love to eat it, so it stays. Both the hermit's shell and the empty snail shell are coated with thick green algae. The yellow stuff in back is the kelp that came with its holdfast last week. I just checked; there are four hermits working on this at the moment.

One of my crabs is very pregnant. I've been trying to get a photo: she's not cooperating. One of these days; now that the days outside are so short, I'll have more time to wait for her.

New word: tafoni

Chapter Number Umpteen in "Why I love blogging."

I've been looking at holes in sandstone for a few years, wondering, not knowing how they were made. Twice, I've written posts about them, here and here, mostly full of questions.

And I've been given some answers on Facebook!

The holes have a name: Tafoni.

Sandstone rock with empty tafoni, Edgewater beach, 2010

Tafoni (singular: tafone) are small cave-like features found in granular rock such as sandstone, granite, and sandy-limestone with rounded entrances and smooth concave walls, often connected, adjacent, and/or networked. They often occur in groups that can riddle a hillside, cliff, or other rock formation. They can be found in all climate types, but are most abundant in intertidal areas and semi-arid and arid deserts. (Wikipedia)

"Small cave-like features ..." And "often ... adjacent ..." That describes the ones I find on our beaches. Other sites mention that they can be large, even room-sized, but our shore tafoni are rarely much more than a couple of inches across.

Often the holes line up around the edge of a flat lump of sandstone. This one is on Stories Beach. (No, I didn't put the small stone on top; that's how I found it.)

But what causes these? How do they form, and why? Why in these positions?

Explanations of their formation include salt weathering, differential cementation, structural variation in permeability, wetting-drying, and freezing-thawing cycles, variability in lithology, case hardening and core softening, and/or micro-climate changes and variation (that is, moisture availability). (Wikipedia)

That's a partial answer, but seems to leave out any biological factors. So what about snails and limpets? And the anemones in the pits?

Tafoni full of tiny snails. Willow Point Beach.

Some researchers believe that, in addition to salt weathering, mollusks and other marine life may also initiate tafoni. They do this by creating small holes in the rocky coastlines, where they attach themselves and extract minerals. The hole grows larger over time until eventually the mollusk, or other organism, drops off. The hole is then left to the elements, like wind, rain, and tidal water. (WorldAtlas)

"Salt weathering". What is that?

Mixing salt cations and water can produce a supersaturated solution. When this solution evaporates, salt crystals precipitate in pores spaces. The resulting crystalline solid precipitated between mineral grains can exert stress and readily cause mineral breakdown. (Tafoni.com Weathering)

Several sites explain this in simple terms. Salt weathering shows up on shore rocks periodically wetted with salt spray. In the intertidal zone, the rocks are underwater most of the time, but spend several hours in the open air daily. In the summer, they are exposed to warm sunlight, and dry out completely.

As the rock dries, the salt crystallizes. These salt crystals expand forcefully enough to create small cavities. In intertidal areas, the drying periods are shorter than on the upper shore, so intertidal tafoni tend to be small.

Thousands of tiny snails in tafoni, Willow Point Beach

So here's my idea, so far: the larger sandstone rocks standing above the intertidal floor dry out sooner, and spend more time out of water. This may be part of the reason for the arrangement of the tafoni. Here, salt crystals create small pits in the soft rock. Tiny snails find food in these holes, and dig them deeper; they have the grating radulas for this task. Limpets also bore into rock to create protected sleeping caves.

More weathering occurs. Wind, waves, crystalizing salt, and some chemical reactions depending on the material forming the rock, all may play their part.

And then along come the anemones. Do they enlarge the holes themselves, maybe by chemical means? Or do they just expand to fit the holes they find?

Anemones in sandstone pits, Edgewater beach, 2010

That still leaves the question of arrangement; why do the tafoni so often form along the rim of sandstone piles? Why do they sometimes cover the whole rock? Why do they often riddle one rock in a group and leave the rest free?

Rim tafoni.

The more I learn, the more questions I have.

Such fun!

(The site, Tafoni.com, has much more information, under many headings. Start with Tafoni.com/Definition and go to -Locations to see tafoni on Mars.)

Rock houses

Anemones are squishy. Touch one (not the tentacles; sometimes they sting). Touch the stalk; it feels like watery Jello. It leaks tears at your touch, and shrinks. Now it's regular Jello texture, still springy, still soft.

They have no teeth, no rasping mechanisms, no scratchy outer shell. So how do they excavate holes in rock?

Sandstone boulder, Willow Point. With ancient anemone homes around the edge.

Another boulder, another set of holes. This is rock, not sand.

Sometimes the holes line up along the edge of a flat rock. Sometimes the whole rock is pock-marked. And the next rock, of the same material, is smooth, without a hole to be seen.

Some holes are just that; old holes. I poke at them with a finger. There's nothing there but rock, hard and dry.

Some holes are occupied. The surrounding rock is hard, but if I touch the centre of a hole, it shrinks away from my finger, leaking tears, exposing a flash of yellow or green jelly.

Anemones in their rocky holes, unhappy because I poked them.

The beach life is layered.  Here, crabs, limpets, and snails in shallow pools, a seaweed level (sea cauliflower and red algae), barnacles on the bottom of a flat rock, and a rim of holes around the upper side. And more barnacles and algae on the top. Crouch and look up at the underside of the rock; there may be a starfish or three.

Why are the holes so often lined up along the edge of flat rocks? Could it be something to do with the currents bringing foods, the way the anemones in my aquarium congregate near the top of the tank, sometimes half out of the water? Do they line up because new babies move only a little way from their parent?

Why do they choose one rock, and not the next? Why is one rock smooth, its neighbour completely pock-marked, and the next one free of holes except for one edge?

Are some of those holes ancient limpet beds, hollowed out by years of tidewaters? Is there a way to tell the difference?

And in my tank, why do the few pink-tipped green anemones who choose to stay at the bottom park themselves mostly on oyster shells, almost never on stone?

I ask them, but they never answer.

Under a glaring sun

Where the intertidal flats are mostly flat slabs of sandstone, critters that usually hide in the sand under rocks when the water recedes, quickly burrowing deeper when their rocks are flipped, either just put up with unfiltered sunlight, or cling tightly to the underside of what few stones are available. There's nowhere to run.

A half-dozen hermit crabs and a Wosnesenski's isopod struggle to stay in the shade of a trio of mussels. I replaced their stone roof gently where I found it.

The sand is a thin dusting on the sandstone. There's no shelter for the critters that can't run and hide elsewhere.The anemones here are under about a half-inch of water.

The green algae, the red seaweed, and the anemones don't mind the sunlight. Even at full tide, they're exposed to it, just slightly shaded by the clear water.

This green algae is probably the same one that pollutes my aquarium, always growing first on the walls closest to the light. The pink-tipped green anemones also benefit from sunlight; they do not photosynthesize, being animals, but carry symbiotic algae in their tissues; these algae produce enough food for themselves and some over for the anemone that hosts them.

Bottoms up

A couple of anemones have started climbing the walls in the aquarium. I took the opportunity to look at them from an unusual point of view.

An orange-striped green anemone. The stripes show up on the base, too. And what are those little coiled white things?

The general structure of a sea anemone is simple. ... Internally, anemones are also simple with only a few anatomical features, largely limited to a throat-like actinopharynx and radiating mesenteries. (Brian McCloskey)

So, maybe they're mesenteries: infoldings of the skin that increase the digestive capacity. Or are those the orangey blobs? And could the squiggles be wormy parasites? Or gonads?

Pink-tipped green anemone. Interesting swirly lines.

This anemone has migrated to just below the surface. I added a bit more water, to avoid leaving it high and dry when I change the cooling ice packs, and the anemone moved on up to the top again. All its relatives (and possible clones) are still settled down on the bottom, in the sand or on oyster shells.

The big plumose anemone, Metridium dianthus, "looks" straight at me, giving me a clear view of her mouth.

A pink-tipped green anemone, from a more usual viewpoint. It's on a moon snail shell, which seems to be growing assorted algae in turquoise and pink.